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112582
3701662
Note on the Relative Chemical Intensities of Direct Sunlight and Diffuse Daylight at Different Altitudes of the Sun
20
24
1,866
15
Proceedings of the Royal Society of London
Henry E. Roscoe|Joseph Baxendell
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0012
null
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1,860
1,850
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null
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II . " Note on the relative Chemlical Intensities of direct Sunlight and diffuse Daylight at different altitudes of the Sun . " i3By HENRY E. RoscoE , F.R.S. , and JOSEPH BAXXENDELL , F.R.A.S. rIeceived February 8 , 1866 . The method of determining the chemical intensity of daylight described by one of us* presents a convenient means of experimentally comparing the intensity of the chemically active rays which reach the earth 's horizontal surface directly from the sun with that of the same rays reflected from the atmosphere and constituting diffuse daylight . For this purpose it is only necessary alternately to expose pieces of the standard sensitive paper , according to the method described in the memoir above mentioned , to the action of the total light of day , and to the diffuse daylight alone , which is easily done by cutting off the sun 's direct rays from the sensitive paper , by throwing upon the paper a shadow cast by a small screen , having an apparent diameter slightly greater than that of the solar disk . In the first case the chemical intensity of the total daylight , in the second that of the diffuse light is determined ; the difference between these two observations giving the chemical intensity of the direct sunlight . As the experiments which we have already made in this direction have led us to conclusions differing altogether from those derived from theoretical considerations concerning the relative chemical intensities of direct and diffuse sunlight , we think that , although this investigation is incomplete , the results are worthy of the attention of the Society . No direct photometrical determinations of the relative intensity of sun and diffuse light have up to this time been made ; but Clausius tl has calculated this relation for varying altitudes of the sun , founding his calculations upon the hypothesis ( generally adopted by meteorologists to explain the red tints of the morning and evening sk ) that the diffused light is reflected , not from the par ' J3akerian Lecture , 1865 . Phil. Trans. 1865 , p. 605 . t Poggendorff ' , i 'Annalen , ' dcl . lxxii . p. 291 . tides of air or solid floating material , but from the minute vesicles of water which are supposed to be always contained in large quantities in the atmosphere . According to this hypothesis , Clausius obtained the following numbers as expressing the intensities of direct sunlight and diffused daylight for altitudes varying from 200 to 60:-Calculated Intensities of Sun 's Altitudes . Total Daylight . Diffuse Light . Direct Sunlight . 200 0-10049 0-06736 0003313 25 ? 0-17808 0'09291 0'08517 30 ? 0-25933 0-11184 0-14749 350 0-34049 0-12654 0-21395 40 ? 0-41957 0-13832 0-28125 i500 0-56686 0-15599 0-41087 160o 0-69442 0-16822 0-52620 ( The intensity of sunlight at an altitude of 90 ? , unweakened by atmospheric absorption , is taken as the unit . ) The measurement of the relative chemical intensities were made at three localities : ( 1 ) Owens College , Manchester , 530 29 ' N. , and 01 9M O W. ; ( 2 ) the Observatory , Cheetham HIill , near Manchester ; and ( 3 ) the summit of the Kinigstuhl , near I-eidelberg , 1900 feet above the sea , in 490 24 ' N. , and 34m 48 " E. We are indebted for the latter observations to Dr. Wolkoff , who kindly forwarded us his results through Professor Bunsen . The following experimental numbers , obtained at Owens College , may serve to illustrate the method adopted ; in most cases several ( four or five ) observations of the inltensities of the total and diffuse light were made quickly one after the other , and the mean of all the readings taken . TABLE I.-Observations at Owens College , Manchester , 530 29 ' N. 011 9"1 0s W. G reenwich Sun 's uns Number Intensity Number Intensity Sun 's Sun 's Intenslity . Da . Mean Time Altiof total of of of of atof Observa Obsel vadifoused Observadirect Angle . tude . Daylight . onsa tion . Ansle . tule . DayLight . tions . Sunlight . 1865 . hm0 Oct. 6 . 12 00 44W . 31 17 073 3 -068 4 -005 7 . 9 30 36 42 E. 23 23 '060 1 -056 1 -004 12 00 48W . 30 54 -063 1 -057 1 -006 18 . 11 25 7 18E . 26 30 -075 2 -056 2 -001 11 45 2 17 E. 26 46.111 2 -089 2 -022 12 30 8 58 W. 26 20 -088 4 '087 4 '001 1 19 21 13 W. 24 15 '071 4 -067 5 -004 2 45 42 43 W. 17 8 -062 2 -053 2 -009 24 . 0 45 12 51W7 . 23 42 -139 3 -113 5 026 1 20 21 41W . 22 4 -123 5 '115 4 -008 Nov.15 12 01 33W . 17 55 -101 5 -082 4 '019 12 40 11 33W . 17 15 -065 4 '063 5 '002 1 15 20 18 W. 15 50 -063 4 '058 5 -005 21 . 12 10 3 43 W. 16 27 -056 5 -055 4 '001 12 30 8 43 W. 16 8 -066 4.058 5 '008 12 45 12 28W . 15 44 '058 4 -050 5 '008 ... ... . As the altitudes here observed vary only from 15 ' 44 ' to 31 ? ? 47 ' , we thought it best to collect the results into two groups , containing the eight highest and eight lowest observed altitudes . TABLE II.-Results of Observations at Owens College . Number of Intensity nten Observations . Altitnde , of Sky or of tie atio of diffused Sun to Sky . of Sun . Sunlight . Sun to Sky Sky . Sun . ofS Daylight . Group 1 33 34 17 ? ? 8 ' -066 -007 0-106 2 20 24 26 38 '074 -008 0-108 The determinations made at Cheetham Hill ( 53 ? ? 30 ' 50 " N. , and Oh 8m 56s W. ) were sixty-three in number , in which the altitude varies from 1 6 ? ? 8 ' to 4 6 ? ? 14 ' , and these are divided into three groups , as follows : TABLE III.-Results of Observations at Cheetham Hill . Number of Intensity Observations . MeAen of Sky or Insty Ratio of Alfitude diffused Sunlight . Sun to Sky . of Sun . Sunlig_h . Sky . Sun . ofSun . Daylight Group 1 23 24 19 ? ? 30 ' '064 -012 0-187 2 22 22 25 31 -091 -019 0 208 3 18 17 34 8 -104 -026 0-250 The range of altitude in the Heidelberg experiments being a much wider one ( viz. from 0 ? to 63 ? ? 49 ' ) , we have been able to arrange these ( containing ninety-nine observations ) in five groups , as follows : TABLE IV.-Results of Observations at Heidelberg . Number of Range of Mean Intensity Intensity ao ObservaAltitude of Altitude of kyor of direct RatS o fS tions . of Sun . of Sun . dffu Sunlight . Daylight . Group 1 10 0 ? to 15 ? ? 7 ? ? 15 ' '048 -002 0-041 2 19 15 -30 24 43 -134 -066 0-472 3 31 30 -45 34 34 -170 -136 0'800 4 22 45 -60 53 37 -174 -263 1 511 5 17 above 60 62 30 '199 -319 1-603 The curves on P1 . I. fig. 1 are derived from the foregoing numbers , the ordinates representing the intensities and the abscissme denoting the corresponding altitudes . The curves marked a , b , c give respectively the observations at Heidelberg , Cheetham Hill , and Owens College ; the dotted curves represent the intensities of the diffuse light , the black curves those of the direct sunlight . The ratio of the sun and skylight for the same places is represented by the curves a , 6 , and c , fig. 2 . In the following Table the experimental ratios are compared with those calculated by Clausius . TABLFE V.-Ratio of Chemical Intensities of direct Sunlight to diffuse Light , Experiments . Sun 's Calculated --Altitude . ( Clausius ) . Heidelberg . Cheetham Hill . Owens College . 20 ? 0-491 0-350 0'19 0'10 25 0-896 0-480 0-20 0'11 30 1-320 0-650 0-23 35 1-690 0-820 0-26 40 2-032 1 00 50 2-634 1-37 60 3-129 1-60 These numbers show that whilst at 20 ? of altitude , according to theory , the relation of the intensities of diffuse light to direct sunlight is as 100 to 49'1 , the experiments at Heidelberg give a relation of 100 to 35 ; those at Cheetham Hill 100 to 19 , and those in Manchester 100 to 10 . If we compare the theoretical ratio for higher altitudes , we find that in our latitudes the ratio even at 35 ? of altitude is only as 100 for diffuse light to 26 for sunlight , whereas theory gives the relation as 100 to 169 . The Heidelberg observations show indeed a more rapid rise in the intensity of the direct sun 's rays , the ratio reaching 100 to 82 for 35 ? of altitude . The great difference between these and the other experimental results must doubtless be ascribed to the considerable elevation ( 1900 feet above the sea ) at which these observations were made . Even at Heidelberg , however , no less than eight observations show that at low elevations the chemical action of the sun becomes altogether inappreciable , whilst that of the diffuse light is still considerable ; and the same inactive condition of direct sunlight at low altitudes has been frequently observed both at Owens College and Cheetham Hill . In these cases the intensity of the sun 's direct visual rays was considerable , and a strong shadow was cast ; but the more highly refrangible rays were altogether absent , and the ratio became infinite . Heidelberg Observations . Altitude . Direct Sun . Diffuse Light . 0 ? ? 34 ' 0000 0-026 1 32 0'000 0-024 2 29 0'000 0-038 3 27 0'000 0-028 60 0'000 0-030 10 40 0'000 0'083 11 51 0'000 0-079 12 58 0'000 0'080 In some of the experiments made at Cheetham Hill the shadow of a small disk was thrown on a horizontal surface of white paper , and careful estimations made of the relative brightness of the shaded and unshaded portions of the surface . A comparison of these results with those obtained at the same time for the chemical rays showed that with the sun at a mean altitude of 25 ? ? 16 ' , the mean ratio of the chemical intensities of direct and diffused light being 0'23 , that of the luminous intensities was 4'00 , or that the action of the atmosphere was 17'4 times greater on the chemically active than on the luminous rays of sunlight . A series of photometrical experiments made afterwards at Owens College gave the following results Mean altitude of the sun ... ... ... . 12 ? ? 3 ' Mean ratio of chemical intensity ... . 0'053 Mean ratio of luminous intensity ... . 1 400 It appears therefore that with the sun at an altitude of 12 ? ? 3 ' , the action of the atmosphere was 26'4 greater on the chemical than on the luminous rays . The foregoing experiments appear to proveI . That the effect of the atmosphere upon the highly refrangible and chemically active solar rays is regulated by totally different laws from those founded upon the hypothesis of the reflexion by means of hollow vesicles of water . II . That the ratio of the chemical intensity of direct to diffuse sunlight for a given altitude of the sun at different localities is not constant , varying with the transparency , &c. , of the atmosphere . III . That this ratio of " chemical " intensity does not in the least correspond to the ratio of " visible " intensity as estimated by the eye ; the action of the atmosphere being 17'4 times greater upon the chemical than on the luminous rays when the sun 's altitude is about 25 ? ? 16 ' , and 26'4 times greater when the sun 's altitude is 12 ? ? 3 ' . _-oc:f ? : . ' & i Vo . a P._ . _/ RATIO OF DIRECT TO DIFFUSED LIGHT AT DIFFERENT ALTITUDES OF THE SUN . / / : / -~~~~ I ... ... ' I_ _ ... ... ... ... ... ... ... ... . . : 11 CbeetkF , aaIfi.-liAL. . fvl7.ia ' ( > ie , . : CHEMICAL INTENSiYV OF DIFFUSED AND DIRECT SUN-LIGHT ' AT DIFFERENT ALTITUDES OF THE SUN . -~--------A-------~--L -I-1I -j~~ k:a ... ..oo ' -8io -Io 17_jO 3^ wnj_ ? L_.0 _. . -^0 2l < ? 0 * 3\0 ? . ^ < 90~~~~1 / 1190( I ' / 7 ? L ... 400._ . * : 04 . | . O00-'QO & 0:00L L. i4t L6c < 67 : a. _H1a ; d.ede & a 6'y , :'- , ia..9,9 o & -e , az,.a ' . il b ' . ? .e ? .wka [ .t 11:iaat-a/ vni . ohs'vrV ' 'o:t/ . a , ' ... ... ... . . & ... ... oa'ae..y___ ? ? 9 ... ... ... --. . | ' ... . " .a^^^JSI/ .r^ssi . 4^ " A & iFi . II I~ . , f , , ; i ' I| I_ -_OP_O~ ... ... ... ... ... ... . . ! _~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ iIiII -----i i " ' ? '---=- ? -"'T-r ? . ? C^"-'U'P r 7j ; i1 It iIi --i L ~__ . _~..___._f_i._ ; _.i . _ ,
112583
3701662
Researches on Acids of the Lactic Series.--No. I. Synthesis of Acids of the Lactic Series. [Abstract]
25
28
1,866
15
Proceedings of the Royal Society of London
E. Frankland|B. F. Duppa
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
4
64
1,463
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112583
null
http://www.jstor.org/stable/112583
null
108,950
Chemistry 2
77.354412
Biochemistry
7.905559
Chemistry
[ -39.25494384765625, -62.668209075927734 ]
" Researches on Acids of the Lactic Series.-No . I. Synthesis of Acids of the Lactic Series . " By E. FRANKLAND , F.R.S. , and B. F. DUPPA , Esq. Received February 14 , 1866 . i(Abstract . ) In the first part of this paper the authors give the details of the synthetical production of numerous acids of the lactic family , which have been briefly described in a series of notes already published in these Proceedings during the years 1863 , 1864 , and 1865 . In the concluding portion of the present paper , they discuss the theoretical considerations which arise out of these investigations . They call attention to the existence of a group of elements , to which they give the name oxalyl and the formula ( C O Ho ) , and which exists not only in all acids of the lactic series , but also in nearly every known organic acid . The isolated molecule of this radical is oxalic acid , { COHo C0 Ho , in proof of which they show that when oxalic ether is acted upon by nascent amyl , it is converted into caproic ether : f C0Eto CBuH22 CB IIT2 COEto+ { CBuH=2 CCOEto . Oxalic ether . Amyl . Caproic ether . Oxalyl is closely related to cyanogen , the two radicals passing into each other in a host of reactions ; hence the production of cyanides from the ammonium-salts of the fatty acids on the one hand , and the synthesis of acids from certain cyanogen compounds on the other , -a reaction first pointed out by Kolbe and Frankland* , and which has of late yielded such important results in the hands of Maxwell Simpsont and of Kolbe and of Hugo MiillerT . C N " C0 Hol . 1CN C N " COHo . Cyanogen . Oxalyl . The researches of these chemists prove that the introduction of cyanogen into an organic compound , and its subsequenit transformation into oxalyl , converts that compound into an acid , or , if already an acid , increases its basicity by unity ( for each atom of oxalyl so developed ) , this result being apparently quite independent of the position of the oxalyl in the molecule . The atom of oxalyl ( as the above molecular formula shows ) may be regarded as methyl ( C H3 ) , in which two atoms of hydrogen have been replaced by one of oxygen , and the third by hydroxyl ( Ho ) . It may be objected that the group of elements , which is thus invested with radical functions , lacks one of the fundamental characteristics of a radical by its proneness to change ; but this characteristic is exhibited by the commonly received radicals in a very varied degree . And even methyl itself , which certainly possesses it in the most marked manner , readily permits of its hydrogen being replaced by chlorine or bromine on the one hand , and by sodium on the other . All compound radicals , the authors remark , are purely conventional groupings of elements intended to simplify the expression of chemical change ; and in this respect they believe the group oxalyl , entering as it does into the constitution of nearly every organic acid , has as valid a claim to a distinct name as the most universally recognized radical . Its admission renders possible the following very simple expression of the law governing the basicity of nearly all organic acids-an organic acid containing n atoms of oxalyl is n basic . The authors classify all acids of the lactic series at present known , or which could be obtained by obvious processes , into the following eight divisions : General formula . C R111 lo 1 . Normal acids ... ... ... ... ... ... . . C0 Ho 2 . Etheric normal acids ... ... ... ... C HR . C0 Ho 3 . Secondary acids ... ... ... ... ... O T2Io OH , Ho 4 . Etheric secondary acids ... ... ... . . C Ho Gf C:lRHo CR11 Ho 5 . Normal olefine acids ... ... ... ... . . ( C H2g ) C0 Ho + qCR IHRo 6 . Etheric normal olefine acids ... ... . . ( C H2 ) , n COHo +f CR2Ho 7 . Secondary olefine acids ... ... ... . . ( C COHo C0 BRo 8 . Etheric secondary olefine acids ... ... ( C H2)n CO Ho. A normal acid of the lactic series may be defined as one in which an atom of carbon is united with oxalyl , hydroxyl , and at least one atom of hydrogen . In the above general formula for these acids R may be either hydrogen , or any alcohol hydrogen . An etheric normal acid is constituted like a normal acid , but contains a monatomic organic radical , chlorous or basylous , in the place of the hydrogen of the hydroxyl . A secondary acid is one in which an atom of carbon is united with oxalyl , hydroxyl , and two atoms of an alcohol radical . An etheric secondary acid stands in the same relation to a secondary , as an etheric normal does to a normal acid . A normal olefine acid is one in which the atom of carbon united with oxalyl is not united with hydroxyl , and in which the atom of carbon united with hydroxyl is combined with not less than one atom of hydrogen . In -1this formula R may be either hydrogen or a monatomic alcohol radical , and the olefine , or diatomic radical of these acids , may belong to either the ethylene , or the ethylidene series . An etheric normal olefine acid differs from a normal olefine acid only in D having the hydrogen of the hydroxyl replaced by an organic radical positive or negative . A secondary olefine acid is one in which the atom of carbon united with oxalyl is not combined with hydroxyl , and in which the atom of carbon united with hydroxyl is also combined with two monatomic alcohol radicals . In the above formula R must be a monatomic alcohol radical . An etheric secondary olefine acid is related to the secondary olefine acids in the same way as the etheric normal olefine acids are related to the normal olefine acids . The numerous cases of isomerism in the lactic series are next examined and explained ; and the authors then show how the radicals which are employed for the production of the synthesized acids may again be separated , thus affording analytical as well as synthetical proof of the constitution of these acids . These investigations have conducted the authors to the following conclusions:1 . All acids of the lactic series are essentially monobasic . 2 . These acids are of four species , viz. normal , secondary , normal olefine , and secondary olefine acids ; and each of these species has its own etheric series of acids , in which the hydrogen of the hydroxyl contained in the positive or basylous constituent of the acid is replaced by a compound organic radical , either positive or negative . 3 . The normal acids are derived from oxalic acid by the replacement of one atom of oxygen , either by two atoms of hydrogen , or by one atom of hydrogen and one atom of an alcohol radical . 4 . The secondary acids are derived from oxalic acid by the replacement of one atom of oxygen by two atoms of monatomic alcohol radicals . V , 5 The olefine acids are derived from oxalic acid by a like substitution of two monatomic positive radicals for one atom of oxygen , with the addition of a diatomic radical ( C. IT2f ) between the two atoms of oxalyl . 6 . The acids of the lactic series stand in the very simple relation to the acids of the acetic series first pointed out by Kolbe , viz. that by the replacement , by hydrogen , of the hydroxyl , ethoxyl , &c. contained ill the positive radical of an acid of the lactic series , that acid becomes converted into a member of the acetic series . 7 . The acids of the lactic series stand in an almost equally simple relation to those of the acrylic series , as is seen on comparing the two following formula:{ C ( C HI ) H Ho C ( C 112 ) IH . CO Ho CO Ho. Lactic acid . Acrylic acid .
112584
3701662
Note on a Correspondence between Her Majesty's Government and the President and Council of the Royal Society regarding Meteorological Observations to Be Made by Sea and Land
29
38
1,866
15
Proceedings of the Royal Society of London
Lieutenant-General Sabine
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0014
null
proceedings
1,860
1,850
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10.1098/rspl.1866.0014
http://www.jstor.org/stable/112584
null
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Meteorology
24.825936
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I. " Note on a Correspondence between Her Majesty 's Government and the President and Council of the Royal Society regarding Meteorological Observations to be made by Sea and Land . " By Lieutenant-General SABINE , P.R.S. Received March 8 , 1866 . Her Majesty 's Government having been pleased to consult the Royal Society on several occasions in the last few years regarding the proper steps to be taken by this country , under the sanction and authority of its Government , for the prosecution , in cooperation with the Governments of other States in Europe and America , of systematically conducted meteorological observations by Land and Sea , it may be desirable to offer to the Fellows a resume of the correspondence , and of the suggestions which from time to time have been tendered on the part of the Society to the several depart . ments of the State . The correspondence commenced by a communication from the Foreign Office in March 1852 , transmitting , by direction of the Earl of Malmesbury , several documents received from foreign governments in reply to a proposition which had been made to them by Her Majesty 's Government , for their cooperation in establishing a uniform system of recording meteorological observations ; and requesting the opinion of the President and Council of the Royal Society in reference to these documents , and more especially in reference to a communication from the Government of the United States of America respecting the manner in which the proposed cooperation might be carried out . The reply of the President and Council was dated May 10 , 1852 . It recognized fully the importance of well-directed and systematically conducted meteorological observations , not only for their scientific value , but also on account of the important bearing which correct climatological knowledge has on the welfare and material interests of the people of every country . With reference to a specific proposal for the adoption , by all countries , of a uniform plan in respect to instruments and modes of observation in meteorological researches on land , the President and Council expressed a doubt whether any practical advantage was likely to be gained by pressing such a recommendation in the then state of meteorological science . Many of the principal Governments of the European Continent had already organized systematic climatological researches throughout their respective States under the superintendence of men eminently qualified by theoretical and practical knowledge , and whose previous publications had obtained for them a general European reputation . The instruments employed in each country had.been constructed under the care of the Superintendents , and the instructions for their use drawn up and published by them ; the observations were also received by them and reduced and coordinated , and were in this state published periodically by the respective governments . To call on countries so advanced in systematically conducted meteorological observations to remodel their instructions and instruments with the view of establishing uniformity in these respects , was scarcely likely to be successful , especially if the request proceeded from a country which " had no similarly organized system extending over its own area . Moreover the discussions which had taken place at the Magnetical and Meteorological Congress assembled at the Cambridge Meeting of the British Association in 1845 , which was attended by the Superintendents of the different continental systems , had manifested so marked a disposition on the part of the meteorologists of the different countries to adhere to their respective arrangements in regard to instruments , times of observation , and modes of publication , as to produce a strong conviction that the suitable time for pressing a proposal for the substitution of a uniform scheme , however advantageous in some respects , had not then arrived . But in respect to Marine Meteorology the case was widely different ; and the suggestions which the President and Council felt it their duty to offer on that subject had a much more positive character , and were directed to immediate action . An application had been made by the Government of the United States to that of our own country to give a greater extension and a more systematic direction to meteorological observations made at sea . Apart from the important scientific bearing of such researches , the wellknown publications of Lieutenant Maury had given to the Government of the United States a fair claim to make such an application to that of our own country , to whose commercial interests a practical knowledge of the meteorological statistics of the ocean was not less important than to those of the United States . Accordingly , in their reply to the Foreign Office , the President and Council did not fail to express emphatically their hope that the application for cooperation , thus earnestly addressed by the Government of the United States , might not be addressed in vain . The following extracts from a memoir addressed by Lieutenant Maury to the Secretary of the United States Navy , printed in " Papers presented to the House of Lords by command of Her Majesty , pursuant to an address dated Februairy 21 , 1853 , " will show that the sugglestions thts made by the President and Council , both in regard to Land and to Sea Meteorological Observations , were fully concurred in by Lieutenant Maury , on his return from an official mission to visit and report upon the meteorological establishments of the principal States of Europe . Lieutenant Maury 's memoir is dated November 6 , 1852 . " I would recommend that the United States should abandon , for the present at least , that part of the 'Universal System ' which relates to the Land , and that we should direct our efforts mainly to the Sea , where there is such a rich harvest to be gathered for navigation and commerce ... . I am induced to make this recommendation in consequence of the evident reluctance with which Russia , Austria , Bavaria , Belgium , and other powers seem to regard any change in their systems of meteorological observations on shore ... . Each country seems to have adopted a system of its own , according to which its labourers have been accustomed to work , and to which its meteorologists are more or less partial . Any proposition having in view for these systems a change so radical as to bring them to uniformity , and reduce them to one for all the world , would , I have reason to believe , be regarded with more or less jealousy by many ... . . Not so , however , with regard to the Sea ; that proposal meets with decided favour and warmest support . " Lieutenant Maury then quotes largely from the Report of the President and Council of the Royal Society ( already referred to ) , and from the anniversary address of the President of the British Association at the Belfast Meeting in 1852 , in illustration of the advantages which navigation and commerce may derive from the extension of maritime researches by the proposed cooperation of Great Britaii and the United States . In June 1854 the Board of Trade informed the President and Council by letter that they were about to submit to Panliament an estimate for an office for the discussion of observations on Meteorology to be made at Sea in all parts of the globe , in conformity with the reconmmendation of a conference held at Brussels in the preceding year ; and that it was their intention to publish from time to time , and to circulate , such statistical results , obtained by means of the observations referred to , as might be considered most desirable by men versed in the science of meteorology , in addition to such other information as might be required for the purposes of navigation . To this end , the Board of Trade were desirous of obtaining the opinion of the Royal Society as to what were the great desiderata in that science , and as to the forms which may be best calculated to exhibit the great atmospheric laws which it may be most desirable to develope . The Board further stated that , " as it may possibly happen that observations on land upon an extended scale may hereafter be made and discussed in the same office , it is desirable that the reply of the Royal Society should keep in view and provide for such a contingency . " In their reply to this communication , dated February 22 , 1855 , the President and Council kept carefully in view the relative importance which the Board of Trade attached to the suggestions which might be olrered respecting observations to be made at sea , and observations to be made on land ; the immediate bearing of the one , and the contingent and eventual bearing of the other . Their reply consequently bore chiefly on points to be investigated by marine observations , -under the several heads of barometric variations ; of those of the dry air and of aqueous vapour ; of the mean temperature of the air ; of the temperature of the sea , and investigations regarding currents ; of storms and gales ; thunderstorms ; auroras and falling stars ; and charts of the magnetic variation . ( Proc. Roy . Soc. , vol. vii . pp. 342-361 . ) These were treated of in their generality , as subjects of investigation to be made ( in the words of the Board of Trade ) " at sea in ail parts of the globe . " Nor was the contingency of observations to be made on land upon an extended scale , " which may hereafter be made and discussed in the same office , " overlooked ; and to enable the Royal Society to be more fully prepared , and to be ready " to provide for the contingency " whenever it should present itself , the President and Council put themselves in communication with several of their foreign members who were known as distinguished cultivators of meteorological science , -having always in view the possibility that , when the occasion should occur , they might be prepared to offer such suggestions as might facilitate the purpose which had been deemed so desirable by Her Majesty 's Government in the preceding year . The chief difficulty which had then presented itself had been the desire shown by the meteorologists of the different European States to adhere to the instruments , and more particularly to the hours of observation , to which they had been accustomed . The hours had been selected partly on grounds of convenience , and partly in the belief that they were those best suited to receive the corrections required in different localities for diurnal and casual variations . The most hopeful way of surmounting the difficulties in question would obviously be the introduction of instruments which should be continuously self-recording ; such instruments would in addition supply the exact instants of the maxima and minima of the different phenomena-points greatly required in the discussion of the laws of extensive atmospherical disturbances . At the epoch of the Cambridge Congress in 1845 it was understood that no perfectly reliable instruments for continuous record were in use amongst the continental observers . The self-recording instruments of M. Kreil , employed at the observatories of Prague , Senftenberg , Vienna , and Munich , and which had also been in use for many months at the Kew Observatory , were not continuously self-recording , and were also , in the opinion of many , not altogether free from objections . The construction of instruments both in magnetism and meteorology which should serve this important purpose and at the same time be free froma causes of error in other ways , had been a cherished object of the Committee of the Kew Observatory from the commencement of that institution . The advance which had been accomplished at a very early period may perhaps best be stated in the following extract from the fourth report of Mr. Ronalds , its Director , published in the volume of the British Association for 1847 , Trans. of Sections , page 30 . " The preliminary experiments on the photographic registration of the atmospheric electrometer , the thermometer , the barometer , and the declination-magnet having been long since completed and published , and their results having warranted the cost and trouble of constructing apparatus of a durable and convenient character , a declination-magnet and a barometer have been mounted at Kew which scrupulously fulfil the requisite conditions without the intervention of those friction-rollers , levers , pivots , or other mechanism which have hitherto rendered self-registering apparatus so objectionable . " Mr. Ronalds added that it was his " intention to provide during the ensuing year complete apparatus on like principles for registering as many of the other meteorological and magnetical instruments as funds will permit . " The instruments which would be required for a complete equipment of a meteorological observatory would be those which should automatically and continuously record ( 1 ) the variations of the atmospheric pressure ; ( 2 ) those of the dry and wet thermometers ; ( 3 ) those of the force and direction of the wind ; and ( 4 ) those of the atmospheric electricity . Of these , Nos. 1 and 2 , as has been already said , had been devised at Kew in or before 1847 . Dr. Robinson 's hemispherical-cup anemometer , of which a description was published in 1851 in the Transactions of the Royal Irish Academy , and which was immediately adopted at Kew , records , in a manner which I believe is universally held to be unexceptionable , the direction and force of the wind at every instant . The electrometer to which Mr. Ronalds referred in his report of 1847 , though highly ingenious and yielding very instructive results , was not continuously self-recording . An electrometer fulfilling this condition was consequently a desideratum until Professor William Thomson devised , and caused to be constructed under his own superintendence at Kew , in the spring of 1861 , the self-recording electrometer which has been subsequently in successful work at that observatory ; thus supplying the fourth apparatus required for a complete meteorological record . It may be added that the Kew Barograph photographs its records self-compensated for temperature ; its curves consequently are in immediate readiness for the lithographer or engraver . Such was the state of instrumental preparation at the Kew Observatory when the untimely death of Admiral FitzRoy , who had been placed by the Board of Trade in charge of the meteorological office established in 1855 , occasioned a renewal of the communications which had taken place on the formation of the office , between the Board of Trade and the Royal Society . In a letter dated May 26 , 1865 , the Board of Trade recalled to the recollection of the Royal Society the recommendations regarding marine meteorology contained in the letter of the President and Council of February 22 , 1855 , stating that those recommendations had been adopted by the Board as the basis of the proceedings of the meteorological department ; and that in conformity therewith instruments and logs had been prepared and furnished to ships proceeding on distant voyages , and had been returned to the office ; and that some progress had been made in carrying into effect the original programme of tabulating these in readiness for statistical charts . It was further stated that " in 1859 or 1860 , the French Government having adopted a system of telegraphing and publishing the actual state of the weather from one place to another , in which Admiral FitzRoy 's cooperation had been sanctioned , a considerable part of the vote previously applied to obtaining and digesting observations was devoted to these telegrams ; and further , that in 1861 , Admiral FitzRoy having grafted on this system of telegraphic communication a system of forecasting the weather , and , on occasions of anticipated storms , the giving of special warnings , communicated by telegraph to the different ports and there made known by hoisting certain signals , the whole or almost the whole of the funds originally voted for the purpose of observations had thus been diverted from their original scientific purpose to an object deemed more immediately practical . " The decease of Admiral FitzRoy afforded , in the judgment of the Board of Trade , a fitting opportunity to review the past proceedings and present state of the meteorological department , and rendered them desirous of again consulting the Royal Society on the constitution and objects of the department , and the mode in which those objects might be most effectually attained . The points on which the opinion of the Royal Society was specially requested were the following:1 . Are the points specified in the letter of the Royal Society of the 22nd of February 1855 still deemed as important for the interests of science and navigation as they were then considered ? ? 2 . To what extent have any of these objects been answered by what has already been done by the meteorological department ? ? 3 . What steps should be talen for making use of the observations already collected ? ? 4 . Is it desirable to make any , and what , further observations on any of the subjects mentioned in the Iloyal Society 's letter of the 22ndl of February 1855 ? ? 5 . What is the nature of the basis on which the system of daily forecasts and storm-warnings established by Admiral Fitz oy rests ? Are they founded on scientific principles , so that they , or any part of them , may be carried on satisfactorily notwithstanding Admiral Fitzloy 's ( lecease ? ? 6 . Can the Royal Society suggest any improvemenit in the form and manner of the process pursued in forecasts and storm-warnings ? ? 7 . Have the lRoyal Society any er general suggestions to make as to the mode , place , 'or establishment in , at , or by which the duties of the meteorological department ct an be be performed ? it being understoodLta tha the Admiiralty are willing to undertake to place in the hands of the iHydrrographer all those observations which can properly be used in framing charts for the purposes of navigation , but not those which relate to meteorology proper or meteorological observations on land . Several documents accompanied this communication , -amongst them a statement by Mr. Babington , chief clerk in Admiral FitzRoy 's office , regarding the method adopted in the department in regard to forecasts and stormwarnings ; and returns , exhibiting a comparison of the probable force of the wind indicated by signals in the years ending March 31 , 1864 , and March 31 , 1865 , and its actual state as reported in the three days following the exhibition of the signals . The reply of the President and Council was dated June 15 , 1865 . It suggested the continuance , for the present , of the practice of forecasts and storm-warnings as before , and the continued issue of instructions and forms to such masters of vessels proceeding on distant voyages as might be expected to make a profitable use of them ; both these duties to be continued under Mr. Babington 's superintendence , by whom in effect they had been carried on for some time previous to Admiral FitzRoy 's decease . And it was further recommended that both the system under which the forecasts and storm-warnings had been hitherto carried on , and the extent and value of the information regarding ocean-statistics which had been accumulated in the office of the Board of Trade , should be subjected to a careful examination . These recommendations were adopted ; and a Committee has been appointed , of three members , one nominated by the Board of Trade , a second by the Admiralty , and a third by the Royal Society , to report on what has been done , and to suggest any modifications which may appear desirable for the future . The report of this Committee is expected to appear very shortly . With reference to the subject of Land Meteorology , the President and Council had been apprised by the Board of Trade , in February 1855 , that " observations on land upon an extended scale might hereafter be made and discussed in the meteorological department of the Board , " and had been requested to be " prepared for such a contingency . " In the more recent correspondence in 1865 , the subject of land observations was again brought forward , and the Royal Society was invited to offer suggestions in reference to it . Thus appealed to , the President and Council would have failed in their duty if they had not replied fully and explicitly to a request proceeding from Her Majesty 's Government , -carefully restricting themselves , in their reply , to such suggestions as their own knowledge enabled them to affirm with confidence could be carried into practical operation , and which at the same time enabled them to respond to the more general inquiry in the letter from the Board of the 26th of May 1865 , viz. " Have the Royal Society any suggestions to make as to the mode , place , or establishment in , at , or by which the duties of the meteorological department can best be performed ? " The reply of the President and Council was as follows:- " There remain , therefore , to be noticed solely the considerations which relate to 'Meteorology roper , ' i. e. to the Land Meteorology of the British Islands . We find that the principal states of the European Continent have almost without exception formed establishments for the collection and publication periodically of the meteorology of their respective countries . The arrangements consist usually of a central office , at which instruments and instructions are provided for a number of stations , greater or less , according to the area which they represent ; at which stations observations are made and transmitted to the central office , where the results of all are reduced , coor . dinated , and published . The small extent of the area comprised by the British Islands in comparison with the territories of many of the European States may requirefewer stations ; but in a matter now so generally attended to and provided for , it seems scarcely fitting that our country should be behind others . There is , moreover , a peculiarity in the meteorological position of the British Islands in respect to Europe generally as its northwestern outpost , in consequence of which an especial duty appears to devolve upon us . M. Matteucci , in a very recent publication , has already made the important remark that extensive atmospheric disturbances which first invade Ireland and England are those which , in winter more especially , extend to and pass the Alps ( although somewhat retarded by them ) , and spread over Italy ; and that storms so telegraphed from England have actually reached Italy , and have been found to correspond with the accounts subsequently received from Italian 3Mediterranean Ports . " A few stations-say six , distributed at nearly equal distances in a meridional direction from the south of England to the north of Scotland , furnished with self-recording instruments supplied from and duly verified at one of the stations regarded as a central station , and exhibiting a continuous record of the temperature , pressure , electric and hygrometric state of the atmosphere , and of the force and direction of the wind-might perhaps be sufficient to supply authoritative knowledge of those peculiarities in the meteorology of our country which would be viewed as of the most importance to other countries , and would at the same time form authentic points of reference for the use of our own meteorologists . The scientific progress of meteorology from this time forward requires indeed such continuous records-first , for the sake of the knowledge which they alone can effectively supply , and , next , for comparison with the results of independent observation not continuous . The actual photograms or other mechanical representations , transmitted weekly by post to the central station , would constitute a lithographed page for each day in the year , comprehending the phenomena at all the six stations , each separate curve admitting of exact measurement from its own base-line , the precise value of which might in every case be specified . " The President and Council suggest that the observatory of the British Association at Kew might with much propriety and public advantage be adopted as the central meteorological station . " It has been already shown , in the earlier part of this communication , that the Kew Observatory possesses all the instruments required in a complete system of continuous self-recording meteorological observation . These are well known to the Directors of many meteorological observatories both at home and abroad , who in several instances , after personal examination , have applied for and obtained for their own establishments similar instruments prepared under the Superintendent of the Kew Observatory , Mr. Balfour Stewart . Thus , Barographs on the Kew pattern have been supplied to Oxford , St. Petersburgh , and Coimbra ; Anemometers to St. Petersburgh , Odessa , Melbourne , Coimbra , Ascension , Madras , Agra , and two meteorological stations established by Admiral FitzRoy ; Electrographs to Lisbon and Coimbra . There would be no difficulty ( as was stated in the letter to the Board of Trade ) in preparing instruments at Kew for affiliated meteorological stations in Britain , and in arranging for their verification and comparison with the Kew standards , as well as in giving to those in whose hands they may be placed such instructions as may ensure uniformity of operation . Such functions constitute in fact part of the original purposes of the Institution at Kew , and are in continual exercise both for magnetism and for meteorology . It is not unreasonable to anticipate that the success of such a system of continuous self-recording meteorological observation , exemplified over the limited area of the British Islands , might occasion its wider extension , and thus contribute to the virtual fulfilment of the desire expressed by Her Majesty 's Government in 1852 " for the adoption of a general and uniform plan of making and recording meteorological observations . " POSTSCRIPT , March 23.-Since this " Note " 'was communicated to the Royal Society , I have read with great satisfaction the opinion expressed in the following extract from the " Report of a Committee assembled at the Board of Trade to consider certain questions relating to the Meteorological Department of the Board , " pages 52 , 53:"There is no doubt that self-recording instruments are urgently needed in the present state of meteorological science , and that they will soon in all probability be largely employed both in this country and abroad . Their advantages are manifest . By reason of the continuity of their records , no wave or variation of any description in any of the meteorological elements can escape notice , and the course of that wave or variation can be tracked with certainty from station to station , and its modification at the time of reaching each station in succession can be accordingly observed . For the same reason one difficulty , now seriously felt , in charting the weather , viz. that which arises from observers in different places and countries adopting different hours of observation , would wholly disappear ; and a further difficulty , viz. that which arises from observers being unpunctual to their professed hours of observation , would disappear also . The unvarying accuracy of the record is an advantage of still greater importance than might be expected by those who have had no experience of the frequent errors to be found in meteorological registers . Each error creates considerable confusion ; it throws doubt on the observations accurately made at neighbouring places ; and that doubt cannot be removed except by the continuity of the records at those places . This continuity is unattainable unless the weather happens to be uniform over a wide district , or unless observations are made at many more places than would be needed , if reliance could be placed upon the accuracy of the observers . Another advantage of self-recording instruments is that their records are independent of particular scales . Their notation is in lines and curves that can be measured with equal facility according to any desired scale . The thermometer lines could be measured at pleasure according to Fahrenheit 's scale , as used in England ; to the Centigrade , as in France ; or to Reaumur 's , as in Germany . The barometer lines could be measured with equal ease in English inches , in millimetres , or in Paris feet . For the various reasons we have mentioned , self-recording instruments are of eminent local and international utility . The establishment of a series of them in England would confer a wide benefit . They would give precision and fulness to the charts of our own weather ; they would set an example that foreign governments would soon follow ; and they would afford material in a very acceptable form to meteorologists at home and abroad for the discussion of the weather of Europe at large . "
112585
3701662
On the Action of Compasses in Iron Ships
38
42
1,866
15
Proceedings of the Royal Society of London
John Lilley
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0015
null
proceedings
1,860
1,850
1,800
5
58
2,423
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112585
10.1098/rspl.1866.0015
http://www.jstor.org/stable/112585
null
null
Biography
36.02385
Measurement
29.770204
Biography
[ 50.72037124633789, -2.761422872543335 ]
II . " On the Action of Compasses in Iron Ships.9 By Mr. JOHN LILLEY . Communicated by Sir W. SNOW HARRIs , F.R.S. Received February 9 , 1866 . Although many ably-written papers upon this subject have at various times appeared , none of them seem to be of that simple practical character as to supersede the necessity of any further investigation of the subject , or deter the author from submitting to the Royal Society the results of many years ' practical experience in the construction of the mariner 's compass , and its adjustment in iron ships . These results are given with a view to advance our knowledge of this important and great practical scientific question , and to add still more to the security of life and property . In the present day , when iron shipbuilding is so widely extending , it is presumed that the most humble offering tending to place the directive action of the compass beyond the reach of disturbing magnetic forces may not be unacceptable . It is unnecessary here to enter into a mathematical investigation of the properties or magnetic condition of iron ships , this part of the subject having been already fully treated and developed by many learned men . The author rather proposes to confine himself to the consideration of the probable causes of the disasters so frequently attendant on the navigation of iron and other ships , through defective compass guidance ; such disasters , according to the author 's experience , may be traced , in a large majority of cases , to one or other of the following causes:38 [ March 8 , 1 . The improper construction and position of the steering binnacle and compass . 2 . The too frequent habit of placing all reliance upon the steering binnacle compass . 3 . Allowing the compasses to be too long in use without due examiniation . 4 . The improper manner in which the compasses have been adjusted . 1 . The construction of the compass is at all times a matter of great importance , but when applied to the case of an iron ship its value is increased tenfold ; it is most essential that the compass should be of the best attainable ( lescription , and so constructed that its centre and pivot should be subject to the smallest possible amount of friction in order that the needles may be entirely free to follow the directive force of the earth , and have at the same time great retentive power . Some years since the author observed , when adjusting an iron steamer 's coinpass furnished by him with very powerful needles , discarded from some previous experiments in magnetism , and which were only 4 inches in length , that more than usually satisfactory results were obtained ; the deviations were of a smaller value , and far more uniform than when using needles of greater length . IHe has since adopted the practice of employing needles not exceeding 6 inches in length , even for cards of the largest diameter . The position of the compass is also important ; it is an objectionable practice of too frequent occurrence , even with the ordinary plane spindle and barrel , to place the binnacle near the steering-wheel ; with the screw apparatus , arms , and levers the practice becomes extremely dangerous , the whole mass , from the process of manufacture , being found highly magnetic . The idea , however , prevails that all this is a matter of indifference , since the counteracting magnets are supposed to neutralize all magnetic disturbance . The reverse , however , is the case ; many instances have come under the author 's notice practically in which errors have arisen solely from this cause , but which ceased to exist on the removal of the binnacle to a distance of 4 feet from the spindle , or twice the original distance . It would be far better , in all cases , if the steering-wheel could be placed before the mizzenmast of ships , instead of abaft and close to the stern , as is generally the case ; compasses would invariably act better and be subject to smaller changes . 2 . It is too frequently the practice to place exclusive reliance upon the steering-compass ; this may be attended with less trouble to the navigator , but is , as regards the safety of the ship , very perilous . As ships are now fitted , the steering-compass is placed very near the stern ; and since in iron ships the magnetic forces are generally concentrated at the two ends of the vessel , it must be obvious that it is placed at that spot where the greatest variations may be expected . Every iron ship should be furnished with a properly constructed standard binnacle not less than 5 feet high above the deck , suitably placed , and containing a compass fitted in the most con venient manner for taking observations without the aid of compensating magnets . By this compass alone should the ship be navigated ; the steering-compass is simply the helmsman 's guide . Many iron ships have been fitted with two navigating binnacles , the one for steering , and the other at the fore part of the poop , both furnished with compensating magnets , and obviously both subject to the same changes incident to the change of hemisphere ; cases of ships thus fitted have come under the author 's notice , in which many providential escapes from wreck have occurred on the return passage from India ; in one particular instance , land was made on the coast of Ireland when the commander imagined he was entering the channel , an error that could not have arisen had the ship been furnished with an uncompensated standard compass instead of a compensated compass . In the uncompensated compass , the changes of deviation are far less than would be found in a compensated compass placed not more than 2 feet above iron beams . Very full directions on this subject will be found in the valuable work of the late Capt. E. J. Johnson , R.N. , and it is much to be regretted that this work is not more studied by commanders and officers of iron ships . 3 . Frequent disasters have been found to occur in consequence of allowing the compass to be too long in use without due examination , more particularly in steam-vessels going short voyages ; the author is led to this conclusion from the fact of having readjusted iron vessels ' compasses stated to be largely in error , but subsequently found , on swinging the ship , to have a comparatively small error , the supposed error being referable to a defective centre and pivot in the compass itself , which prevented the needle from reaching its meridional position . In such cases an error of 8 ? or 10 ? has been often observed ; the importance of such an error in narrow channels is too obvious to require comment . There are valuable and simple appliances which to a very great extent remove this difficulty , and which are comparatively inexpensive ; it is to be much regretted that a great indifference to the state of vessels ' compasses exists in the minds of those under whose care the compasses are often placed , and who , it might be expected , would from experience have been more sensitively alive to the absolute necessity of keeping the compasses , as far as possible , in a state of efficiency . If a compass looks clean upon its surface , it is believed to be in a perfect state , although it may have been stowed away with the card upon the pivot without any protection , thus interfering with the most important of its working parts ; as a consequence , the card , when required for use , will be sluggish upon its pivot , and a false indication of the direction of the vessel 's head is an unavoidable result . 4 . A defective adjustment of the compass is again a vital source of error . This mainly depends , 1 , on the locality in which the vessel is swung , which is too often a dock , where other iron vessels lie in dangerous proximity ; 2 , a want of due precaution on the part of the adjuster , in the place selected for the shore-compass . This is a matter of great importance , far more than is often supposed . As the corrections made on board necessarily depend upon the bearings given from the shore , if these are faulty , the ship 's compass cannot be otherwise than incorrect . The author has more than once seen a shore-compass within a very short distance of an iron shed . The prevailing practice of swinging a ship in the short space of two hours is also very objectionable ; it is utterly impossible to regulate compensating magnets , and to make the requisite observations for the use of soft iron , in so short a time ; it does not allow the vessel to be stayed upon the several points for a sufficient scrutiny of the compasses , sometimes three in number , and the results are too often merely guessed at , and thus all the advantages of that admirable system of adjusting iron vessels ' compasses , introduced by the Astronomer Royal , and which are invaluable to our coasting and short voyage vessels , are , to a great extent , negatived . London is unfortunately very badly provided with the means of adjusting the compasses of iron vessels , and , as their number is so much increasing , this subject is daily becoming more important ; the docks are crowded , and it is by mere chance that in the Victoria Dock , the only available dock at our command , a sufficiently clear space is to be met with . Greenhithe remains as the last resource in this dilemma ; here moorings have been laid down by the City authorities for the use of merchant-vessels , but they are too near the edge of the tide . A very strong down current exists ; the entire space of slack water in the Reach is occupied by two sets of moorings for the use of the Royal Navy , It would be a very great boon if one of these sets of moorings were allowed to be used by the merchant service , when not required for Her Majesty 's Navy . It rarely happens that both sets of moorings are at the same time required for use . As the swinging a ship , moreover , at Greenhithe is entirely dependent upon the tide , it must be commenced with the flood , added to which , the operation is often much impeded by the wind , so that in the winter months , when the days are short , and the seven hours of ebb occur during nearly the whole of daylight , much serious delay is the result ; the author has often occupied three days in adjusting a ship 's compasses . The construction of a dock for this purpose would be very desirable ; the expense may be urged against the proposal ; but surely in London , one of the greatest mercantile cities in Europe , such an undertaking should be regarded as a national matter , and it is believed that shipowners would not object to pay a small rate of charge for the use of such a dock which might render it self-supporting . An opportunity for constructing such a dock may possibly arise in the formation of the new docks at Dagenham , where the expense of an entrance would be saved by simply making a basin from the dock large enough to swing a ship 400 feet in length round a dolphin placed in the centre , and well supplied with mooring-posts for ropes to be made fast to , and a suitable spot for the shore observer--of course removed from all possibility of attraction by iron in the immediate vicinity ; such basin to be kept exclusively for this purpose , and known as " The Ship-swinging , " or " The Compassadjusting " Dock . With the view of deducing a practical result from what has been advanced in the foregoing remarks , the author would most strongly urge the necessity of some offcial inspection of iron vessels with reference to their compass-fittings . A code of rules and instructions might be laid dowi for this purpose ; this would be essential in the cases of new ships ; old ships should be examined at stated times , and certificates of compass adjustment be recognized by the appointed officer solely from those who can furnish evidence of having been properly instructed by competent persons , so that such an important work should not be allowed to be taken up and carried on by any amateur as his fancy may dictate . It may be a question how far a Government inspection would be cordially received by shipowners or public companies ; it might by some be regarded as an undue interference ; the Government also might be indisposed to incur the cost of an extra office , with all its details ; it mright be more properly thought a matter for the consideration of Lloyd 's . It is a question assuredly in which underwriters are largely and personally interested , and they already hold arbitrary powers as concerns the construction of the hull of a ship . The simple question of the compass as a means of safety is comparatively disregarded . The above suggestions are offered with great deference , and the author would rather leave the subject in the hands of those more conversant with legislation than himself ; but he cannot refrain from repeating that the results of his own practical experience ( which has been of no small amount ) convince him that an official supervision1 of the compass-fittings of iron ships has become , from various causes , absolutely requisite .
112586
3701662
On the Tidal Currents on the West Coast of Scotland
42
46
1,866
15
Proceedings of the Royal Society of London
Archibald Smith
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0016
null
proceedings
1,860
1,850
1,800
5
80
2,235
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112586
10.1098/rspl.1866.0016
http://www.jstor.org/stable/112586
null
null
Geography
61.19681
Meteorology
24.204003
Geography
[ 45.68946075439453, 33.56230545043945 ]
III . " On the Tidal Currents on the U W\est Coast of Scotland . " By ARCHIIBALD SMlITI , M.A. , ? F..S . Received March 1 , 1866 . The tidal currents on that part of the west coast of Scotland which is comprised between the Mull of Cantyre and the Island of Mulll r]un in general with great velocity . Their velocity , direction , and the time of their change , or of slack water , are therefore matters of great importance to navigators . On the other hand , the rise and fall of the tide is so small , and the depth of water in the chaninels and the harbours so considerable , that the times of high and low water are of comparatively small importance . While the laws of the currents are thus of more importance than the laws of the rise and fall of the tide , they are also much more simple . The times of high and low water are very different at different parts of the [ Mar. 8 , coast , while the times of slack water are nearly the same throughout the whole region in question . In a great part of this region the current , which sets for six hours in one direction , has no distinct title to be considered . either a flood tide or an ebb tide . The consequence is , that to describe the laws of the currents by reference to the time of high and low water , introduces great and unnecessary complexity . The application to the currents of the method first applied by Admiral Beechey to the tidal stream of the Englisih C(hannel and German Ocean ( Phil. Trans. 1851 , p. 703 ) introduces at once order and simplicity , and makes that intelligible which before was only a confutsed maze . In the following paper an attempt is made , from the materials to be found in the charts of the Admiralty Survey of the west coast of Scotland , now nearly completed , to obtain a first approximation to a tidal chart of the west coast of Scotland . For this purpose I have , with the kind assistance of Commander Evans , F.R.S. , the first Naval Assistant to the iHydrographer of the Navy , deduced from the charts all the information to be there found as to the direction and times of change of the tidal streams , as well as the times of high and low water . The latter are indicated in the usual way by Roman numerals , which , to avoid confusion , are always within the land . The times of change and direction of the currents are described by a particular symbol which I have found convenient for the purpose , and which I will now describe . In the seas which we are considering , the stream at any point generally flows for six hours in one direction and for six hours in the opposite direction . This may be conveniently indicated by the following symbol:which indicates a stream flowing from XII . o'clock to VI . towards the east , and from VI . to XII . towards the west . In this notation , for simplicity , the interval of the tide is considered as 12 hours instead , as it really is , about 1211 2 'm . T bhe hours are expressed in Greenwich mean time . The same symbol is adapted to the case of a stream flowing longer in one direction than in the other . Thus in the Sound of Sanda the stream at full and change may be indicated by V xj indicating that it flows seven hours towards the west and five hours to the east . The velocity of the stream may be expressed by the length of the figure , or sometimes more conveniently by separate lines , the terminations of which are well marked as --- , the length of the lines indicating either the velocity at the middle of the stream , or , if it is found more conveniient , the whole distance which a particle of water moves in one tide . E2 I may observe that an analogous symbol may be used to express the more complicated tides which occur where different streams meet . Thus near the Eddystone the stream may be expressed by a symbol of this kind:4 the bearing and distance of the centre of the diagram from any inumeral indicating the direction and rate of stream at that hour . The time of high and low water in the region which we are considering may be thus described . Near the two extremities , viz. the Giant 's Causeway and the Island of Eysdill , the time of high water at full and change is nearly VI Greenwich time , being very nearly that due to the Great Atlantic tidal wave propagated from S.W. to N.E. , and the same is very nearly the hour of high water on the chain of islands of which Isla , Jura and Scarba are the chief . But along the coast of the mainland of Ireland and Scotland the case is very different . Between these two countries is the great opening into the Liverpool basin , in which it is high water about XI . The change in the time of high water takes place by the following gradations:-At Giant 's Causeway it is high water about VI , , at Ballycastle VII . , Torpoint X. , Mull of Cantyre XI . , Gigha II . , Loch Killispoint IV . , Eysdill and Scarba V , Jura and Islay VI . But while the hour of high water varies , the stream through nearly the whole of the region runs from X. to IV . in one direction and from IV . to X. in the other . Between the Mull of Cantyre and the N.E. coast of Ireland , the X. to IV . stream runs to the north . The most westerly part turns to the west , and runs through the Sound of Rathlin along the north coast of Ireland ; the central part flows to the N.W. past the lihynns of Islay ; the easterly part , which has flowed partly through the Sound of Sanda , turns sharply round the Mull of Cantyre , and flows to the northward , pouring with great velocity through the narrow openings in the chain of islands , viz. , the Sound of Islay between Islay and Jura , the Gulf of Corry Vreckan between Jura and Scarba , the little Corry Vreckan between Scarba and Lunga , the Slate Isles and the Cuan Sound ; of these the little Corry Vreclsan is quite impassable ; and Corry Vreckan and the Cuan Sound are seldom attempted except near slack ' , ater . These channels open into the basin which lies between Jura and Iona-a comparatively tideless sea , owing apparently to the circumstance of the ocean tide from the outside of Isla rising to nearly the same height as that b ' " " " " ' ' " " " '^ " which pours through the openings , so that the tidal stream would be little altered by building a dam from Islay to the Ross of Mull . The question may now be asked , Is the great X. to IV . stream which has just been described a flood or an ebb tide ? So far as regards the Mull of Cantyre , Fairhead , and all that lies to the south or east , it is a true ebb tide . So far as regards Jura , Scarba , and the coast to the north and east , it is a true flood tide ; but as regards a great part of the region in question , it cannot be called either a flood or an ebb tide , and much confusion is occasioned in the Charts by attempting so to distinguish it . At the south end of Gigha in the Admiralty charts an arrow is laid down , indicating that the flood tide runs to the northward ; and a few miles south of this , another arrow is laid down , indicating that the flood tide runs to the southward . From these arrows we might expect to find at this place a meeting of the tide and a sudden change in the direction of the flood stream . But the stream which is indicated by these arrows is nothing more than the great X. to IV . northerly current which we have described . The spot which is treated as a meeting of the tides , is merely that at which it is high water at I. North of this , for more than three hours of the X. to IV . stream , the tide is rising , and it is indicated as a flood tide . South for more than three hours the tide is falling , and it is indicated as an ebb tide . On the south and west coast of Isla the confision is greater . In some of the charts , the incoming stream is marked as the flood , in others , and perhaps with better reason , the outgoing tide . It is in truth neither the one nor the other . The extreme complication which arises from describing the time of change of the stream by reference to the time of high and low water will now appear ; thus we should have to say that in the Sound of Sanda , the ebb stream begins two hours before high water ; at the Mull of Cantyre , one hour before high water ; a little north of this again two hours before high water . At the south of Gigha we might say indifferently , that the flood tide runs to the south and begins three hours before low water , or that it runs to the north and begins three hours after low water ; in the Sounds of Islay and the Gulf of Corry Vreckan that it begins an hour before low water ; and in describing the streams along the north coast of Ireland , we have even greater complication . The direction of the tidal streams on the rest of the west coast of Scotland is easily described . The X. to IV . stream , through the course which I have described , becomes an XI . to V. stream at the outside of Isla , and through the Sound of lona . The stream which sets to the northward up the Sound of Jura fills the Linnhe Loch , and causes high water at the south end of the Sound of Mull at half-past V. , whilst the high water caused by the ocean tide at the north end of the Sound of Mull is an hour later ; the consequence , as may easily be seen , is that nearly the whole flood tide through the Sound of Mull runs to the northward , and the nearly whole ebb tide runs to the southward . The tides round the island of Sky are comparatively simple . The V. to XI . tide from the outside of Mull is gradually retarded to a VI . to XII . stream at the outside of Sky , and then as it rounds the north end of Sky , it is met by the tidal stream which has rounded the north end of the island of Lewis , and bends round into the inner Sound of Skve , where it becomes a VII . to I. tide ; the course of both streams being nearly the same as if there were an embankment from Loch Shell in the island of Lewis to Ru Rea on the coast of Ross-shire . At the same time , another branch of the tide which has rounded the point of Ardnamurchan flows through the Sound of Sky as a XII . to VI . tide , and being an hour earlier than the tide which has rounded the north end of Sky , it pours with great velocity through Kyle Rea , but only to fill Loch Alsh and Loch Duich ; the retardation which it meets with in so doing , making the rise inside of the narrows at Kyle Akin so nearly contemporaneous with the rise outside , that there is little stream through that narrow opening ; the flood stream , as I am informed , sometimes flowing in one direction and sometimes in the other , according to the prevailing winds . There are many more minute details in these streams which have features of great interest . I have not , however , ventured in the present imperfect state of the data which we possess to enter upon these . I ventlre , however , to express a hope that before the survey is completed , the data may be obtained for showing , and that the charts may show the direction and rate of the stream at every place and at any time .
112587
3701662
On a Possible Geological Cause of Changes in the Position of the Axis of the Earth's Crust
46
54
1,866
15
Proceedings of the Royal Society of London
John Evans
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0017
null
proceedings
1,860
1,850
1,800
9
79
4,493
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112587
10.1098/rspl.1866.0017
http://www.jstor.org/stable/112587
null
null
Fluid Dynamics
50.760779
Geography
27.646867
Fluid Dynamics
[ 51.3262939453125, -18.335834503173828 ]
" On a possible Geological Cause of Changes in the Position of the Axis of the Earth 's Crust . ' By JO . HN EVANS , F.R.S. Sec. G.S. Received February 28 , 1866 . At a time when the causes which have led to climatal changes in various parts of the globe are the subject of so much discussion , but little apology is needed for calling the attention of this Society to what possibly may have been one of these causes , though it has apparently hitherto escaped observation . That great changes of climate have taken place , at all events in the northern hemisphere of the globe , is one of the best established facts of geology , and that corresponding changes have not been noticed to the same extent in the southern hemisphere may possibly be considered as due , rather to a more limited amnount of geological observation , than to an absence of the phenomena indicative of ' suchi alterations in climatal conditions having occurred . [ Mar. 15 , The evidence of the extreme refrigeration of this portion of the earth at the Glacial Period is constantly receiving fresh corroboration , and various theories have been proposed which account for this accession of cold in a more or less satisfactory mannaer . Variations in the distribution of land and water , changes in the direction of the Gulf-stream , the greater or less eccentricity of the earth 's orbit , the passage of the Solar System through a cold region in space , fluctuations in the amiount of heat radiated by the sun , alternations of heat and cold in the northern and southern hemispheres , as consequent upon the precession of the equinoxes , and even changes in the position of the centre of gravity of the earth and consequent displacements of the polar axis , have all been adduced as causes calculated to produce the effects observed ; and the reasoning founded on each of these data is no doubt familiar to all . The possibility of any material change in the axis of rotation of the earth has been so distinctly denied by Laplaceand all succeeding astronomers , that any theory involving such a change , however tempting as affording a solution of certain difficulties , has been rejected by nearly all geologists as untenable . Sir I-enry Jamest , however , writing to the 'Athenaeum ' newspaper in 1860 , stated that he had long since arrived at the conclusion that there was no possible explanation of some of the geological phenomena testifying to the climate at certain spots having greatly varied at different periods , without the supposition of constant changes in the position of the axis of the earth 's rotation . I-e then , assuming as an admitted fact that the earth is at present a fluid mass with a hardened crust , showed that slaty cleavage , dislocations , and undullations in the various strata are results which might be expected from the crust of the earth having to assume a new external form , if caused to revolve on a new axis , and advanced the theory that the elevation of mountain-chains of larger extent than at present known produced these changes in the position of the poles . The subject was discussed in further letters from Sir Henry James , the Astronomer Royal , Professors Beete Jukes and I-ennessy , and others , but throughout the discussion the principal question at issue seems to have been whether any elevation of a mountain-mass could sensibly affect the position of the axis of rotation of the globe as a whole , and the general verdict was in the negative . At an earlier period ( 1818 ) the late Sir John Lubbock , in a short but conclusive paper in the 'Quarterly Journal of the Geological Society ' : pointed out what would have been the effect had the axis of rotation of the earth not originally corresponded with the axis of figure , and also mentioned some considerations which appear to have been absent from Laplace 's calculations . * Mec . C61 . , vol. v. p. 14 . t A.thenauinm , Aug. 25 , 1860 , &c. + Vol. v. p. 5 . in the Sir John Lubbock , however , in common with other astronomers , appears to have regarded the earth as consisting of a solid nucleus with a body of water distributed over a portion of its surface ; and there can be but little doubt that , on this assumption of the solidity of the earth , the usually received doctrines as to the general persistenceof the direction of the poles are almost unassailable . Directly , however , that we argue from the contrary assumption that the solid portion of the globe consists of a comparatively thin , but to some extent rigid crust with a fluid nucleus of incandescent mineral matter within , and that this crust , from various causes , is liable to changes disturbing its equilibrium , it becomes apparent that such disturbances may lead , if not to a change in the position of the general axis of the globe , yet at all events to a change in the relative positions of the solid crust and the fluid nucleus , and in consequence to a change in the axis of rotation , so far as the former is concerned . The existence in the centre of the globe of a mass of matter fluid by heat , though accepted as a fact by many , if not most geologists , has no doubt been called in question by some , and among them a few of great eminence . The gradual increase of temperature , however , which is found to take place as we descend beneath the surface of the earth , and which has been observed in mines and deep borings all over the world , the existence of hot springs , some of the temperature of boiling water , and the traces of volcanic action , either extinct or still in operation , which occur in all parts of the globe , afford strong arguments in favour of the hypothesis of central heat . And though we are at present unacquainted with the exact law of the increment of heat at different depths , and though , no doubt , under enormous pressure the temperature of the fusing-point of all substances may be considerably raised , yet the fact of the heat increasing with the depth from the surface seems so well established that it is highly probable that at a certain depth such a degree of heat must be attained as would reduce all mineral matter with which we are acquainted into a state of fusion . When once this point was attained , it seems probable that there would be no very great variation in the temperature of the internal mass ; but whether the whole is in one uniform state of fluidity , or whether there is a mass of solid matter in the centre of the fluid nucleus , are questions which do not affect the hypothesis about to be considered . Those who are inclined to regard the earth as a solid or nearly solid mass throughout , consider that many volcanic phenomena may be accounted for on the chemical theory , which has received the support , among others , of Sir Charles Lyell. . But apart from the consideration that such chemical action must of necessity be limited in its duration , the existence of local seas of fluid matter , resulting from the heat generated by intense chemical action , would hardly account for the increase of heat at great depths in places remote from volcanic centres ; and the rapid transmission of shocks of earthquakes and the enormous amount of upheaval and subsidence as evidenced by the thickness of the sedimentary strata , seem inconsistent either with the general solidity of the globe or any very great thickness of its crust . The supposition that the gradual oscillations of the surface of the earth , of which we have evidence all over the world as having taken place ever since the formation of the earliest known strata up to the present time , are due to the alternate inflation by gas and the subsequent depletion of certain vast bladdery cavities in the crust of the earth , can hardly be generally accepted . Those who wish to see the arguments for and against the theory of there being a fluid nucleus within the earth 's crust , will find them well and fairly stated in Naumann 's 'Lehrbuch der Geognosie'* . AMy object is , not to discuss that question , but to point out what , assuming the theory to be true , would be some of the effects resulting from such a condition of things , more especially as affecting climatal changes . The agreement or disagreement between these hypothetical results and observed facts may ultimately assist in testing the truth of the assumption . The simplest form in which we can conceive of the relations to each other of a solid crust and a fluid nucleus in rotation together is that of a sphere . Let ACBD be a hollow sphere composed of solid materials and of perfectly uniform thickness and density , and let it be filled with the fluid matter E , over which the solid shell can freely move , and let the whole be in uniform rotation about an axis F G , the line CD representing the equator . A - ? cc It is evident that in such a case , the hollow sphere being in perfect equilibrium , its axis and that of its fluid contents would perpetually coincide . 1866 . ] 49 -*2nd edit ; . , 1.858 , vol. i. p. 36 , in the If , however , the equilibrium of the shell or crust be destroyed , as , for instance , by the addition of a mass of extraneous matter at H , midway between the pole and the equator , not only would the position of the axis of rotation be slightly affected by the alteration in the position of the centre of gravity of the now irregular sphere , but the centrifugal force of the excess of matter at 11 would gradually draw over the shell towards D until , by sliding over the nucleus , it attained its greatest possible distance from the centre of revolution by arriving at the equator . The resultant effect would be that though the whole sphere continued to revolve around an axis as nearly as possible in the line F G , yet the position of the pole of the hollow shell would have been changed by 45 ? , as by the passage of II to the equator the points I and K would have been brought to the poles by spirals constantly decreasing in diameter , while A and B , by spirals constantly increasing , would have at last come to describe circles midway between the poles and the equator . The axis of rotation of the hollow sphere and that of its fluid contents would now again coincide , and would continue to do so perpetually unless some fresh disturbance in the equilibrium of the shell took place . If instead of the addition of fresh matter at H1 we had supposed an excavation or removal of some portion of the shell , a movement in the axis of rotation of the shell would also have ensued , since from the diminished centrifugal force of that portion of the hollow sphere where the excavation had taken place , it would no longer equipoise the corresponding portion on the opposite side at I , and the excavated spot would eventually find its way to the pole . In order more clearly to exhibit these effects , I hyave prepared a model in accordance with a suggestion of Mr. Francis Galton , F.R.S. , in which a wheel representing a section of a hollow sphere has its axis , upon which it can freely turn , fixed in a frame , which is itself made to revolve in such a manner that the axis of its rotation passes through one of the diameters of the wheel , and coincides with what would be the axis of the sphere of which the wheel is a section . In the periphery of the wheel are a number of adjustable screws with heavy heads , so that , by screwing any of them in or out , the addition of matter or its abstraction at any part of the sphere may be represented . If by adjusting these screws the wheel could be brought into perfect equilibrium , its position upon its own axis would remain unchanged in whatever position it was originally placed , notwithstanding any amount of rotation being given to the frame in which it is hung ; but practically it is found that with a certain given position of the screws a certain part of the wheel coincides with the axis of the frame , or becomes the pole around which the sphere revolves . The rim of the wheel is graduated so as to show the position of the poles in all cases , and generally speaking the wheel always settles down after rotation with the pole within three or four degrees of the same spot , if no alteration has been made in the adjustment of the screws , though of course what was the uppermost pole may become the lower one ; and in some cases the wheel may be in equilibrio with a projecting screw either above or below the equator , in which case there may be four readings on the circle at the index-point , according as the one pole or the other is uppermost , and the projecting screw is above or below the equator . With the screws on the wheel evenly balanced , a slight alteration in the adjustment of any of them immediately tells upon the position of what , for convenience sake , may be called the poles , except , indeed , in such cases as screwing outwards those already at the equator , or making similar alterations in the adjustment of two screws at equal distances on either side of one of the poles . If a screw be turned outwards so as notably to project at any spot , no matter how near to the pole , it will be found , after the machine has been a short time in revolution , in the region of the equator . Or again , if one or , better still , two opposite screws at the equator be turned inwards , they will be found after a short period of revolution at the poles . Now let us assume for a moment that , though the crust was partially covered by water , the earth , instead of being a spheroid , was a perfect sphere , consisting of a hardened qrust of moderate thickness supported on a fluid nucleus over which the crust could travel freely in any direction , but both impressed with the same original rotatory motion , so that without some disturbing cause they would continue to revolve for ever upon the same axis , and as if they were one homogeneous body . Let us assume , moreover , that this crust , though in perfect equilibrium on its centre of rotation , was not evenly spherical externally , but had certain projecting portions , such as would be represented in Nature by continents and islands rising above the level of the sea . It is evident that so long as those continents and islands remained unaltered in their condition and extent , the relative position of the crust to the enclosed fluid nucleus would remain unaltered also . But supposing those projecting masses were either further upheaved from some internal cause , or worn down and ground away by the sea or by subaerial agency and deposited elsewhere , it seems impossible but that the same effects must ensue as we see resulting upon the model from the elevation and depression of certain screws , and that the axis of rotation of the crust of the sphere would be changed in consequence of its having assumed a fresh position upon its fluid nucleus , though the axis of the whole sphere might have retained its original direction , or have altered from it only in the slightest degree . An irregular accumulation of ice at one or both of the poles , such as supposed by M. Adhdeftar , would act in the same manner as an elevation of the land ; and even assuming that the whole land had disappeared from above the surface of the sea , yet if by marine currents the shallower parts of the universal ocean were deepened and the deeper parts filled up , in the there would , owing to the different specific gravity of the transported soil and the displaced water , be a disturbance in the equilibrium of the crust , and a consequent change in the position of its axis of rotation . Now if all this be true of a sphere , it will also , subject to certain modifications , be true of a spheroid so slightly oblate as our globe . The main difference in the two cases is , that in a sphere the crust may assume any position upon the nucleus without any alteration in its structure , while in the case of the movement of a spheroidal crust over a similar spheroidal nucleus , every portion of its internal structure must be more or less disturbed as the curvature at each point will be slightly altered . The extent of the resistance to an alteration of position arising from this cause will depend upon the oblateness of the spheroid and the thickness and rigidity of the crust ; while the thicker the latter is , the less also will be the proportionate effect of such elevations , subsidences , and denudations as those with which we are acquainted . The question of friction upon the nucleus is also one that would have to be considered , as the internal matter though fluid might be viscous . It will of course be borne in mind that the elevations and depressions of the surface of the globe are not , on the theory now under consideration , regarded according to the proportion they bear to the earth 's radius , but according to their relation to the thickness of the earth 's crust ; and that , even assuming Mr. Hopkins 's extreme estimate to be true , yet elevations or depressions , such as we know to have taken place , of 8000 or 10,000 feet , bear an appreciable ratio to the 800 or 1000 miles which he assigns as the thickness of the earth 's crust . It is , however , to be remarked that the extremely ingenious speculations of Mr. Hopkins are based on the phenomena of precession and nutation , and that if once the possibility of a change in the position of the axis of rotation of the earth 's crust be admitted , it is not improbable that the value of some of the data upon which the calculations of these movements are founded may be affected . The supposition of the thickness of the crust being so great seems also not only entirely at variance with observed facts as to the increase of heat on descending beneath the surface of the earth , but to have been felt by Mr. Hopkins himself to offer such obstacles to any communication between the surface of the globe and its interior , that he has had recourse to an hypothesis of large spaces in the crust at no great depth from the surface , and filled with easily-fusible materials , in order to account for volcanic and other phenomena . But though it may be possible to account for volcanoes upon such an assumption , yet , as already observed , the phenomena of elevation and depression , such as we find to have taken place , and more especially the existence of vast geological faults , cannot without enormous difficulty be reconciled with such a theory . Taking the increment of heat as 1 ? Fahrenheit for every 55 or 60 feet* in descent , a temperature of 24000 Fahr. would be reached at about 25 miles , sufficient to keep in fusion such rocks as basalt , greenstone , and porphyry ; and such a thickness appears much more consistent with the fluctuations in level , and the internal contortions and fractures of the crust which are everywhere to be observed . Sir William Armstrong , on the assumption of the temperature of subterranean fusion being 3000 ? Fahr. , considers that the thickness of the film which separates us from the fiery ocean beneath would be about 34 miles . Even assuming a thickness of 50 miles , so as to make still greater allowance for the increased difficulty of fusion under heavy pressure , the thickness of the crust would only form one-eightieth part of the radius of the earth ; or if we represent the earth by a globe 13 feet in diameter , the crust would be one inch in thickness , while the difference between the polar and equatorial diameters would be half an inch . In such a case , the elevation or wearing away of continents such as are at present in existence , rising , as some of them do , nearly a quarter of a mile on an average above the mean sea-level , would cause a great disturbance in the equilibrium of the crust , sufficient to overcome considerable resistance in its attempts to regain a state of equilibrium by a movement over its fluid nucleus . Whether the thickness of the earth 's crust was not in early geological times less than at present , so as to render it more susceptible of alterations in position-whether the spheroid of the fluid mineral nucleus corresponds in form with the spheroid of water which gives the general contour of the globe-whether or no there are elevations and depressions upon the nucleus corresponding to some extent with the configuration of the outer crust , and whether the motion of the crust upon it , besides effecting climatal changes , might not also lead to some elevations and depressions of the land , and produce some of the other phenomena mentioned by Sir Henry James , are questions which I will leave for others to discuss . My object is simply to call attention to what appears to me the fact , that if , as there seems reason to suppose , our globe consists of a solid crust of no great thickness resting on a fluid nucleus , either with or without a solid central core , and if this crust , as there is abundant evidence to prove , is liable to great disturbances in its equilibrium , then it of necessity follows that changes take place in the position of the crust with regard to the nucleus , and an alteration in the position of the axis of rotation , so far as the surface of the earth is concerned , ensues . Without in the slightest degree undervaluing other causes which may lead to climatal changes , I think that possibly we may have here a vera causa such as would account for extreme variations from a Tropical to an Arctic temperature at the same spot , in a simpler and more satisfactory manner than any other hypothesis . The former existence of cold in what are now warm latitudes might , and probably did in part , arise from other causes than a change in the axis of rotation , but no other hypothesis can well account for the existence of traces of an almost tropical vegetation within the Arctic circle . Of the former existence of such a vegetation , the evidence , though strong , is not conclusive . But if the fossil plants of Melville Island , in lat. 7.5 ? N.@ , which appear to agree generically with those from the English coal-meastires , really grew upon the spot where they were now discovered , they seem to afford conclusive evidence of a change in the position of the pole since the period at which they grew , as such vegetation must be considered impossible in so high a latitude . The corals and Orthoceratites from Griffiths Island and Cornwallis Island , and the liassic Ammonites from Point Wilkie , Prince Patrick 's Island , tell the same story of the former existence of something like a subtropical climate at places at present well within the Arctic circle . To use the words of the Rev. Samuel I aughton:t , in describing the fossils collected by Sir F. L. MeClintock , " The discovery of such fossils in situ , in 76 ? N. latitude , is calculated to throw considerable doubt upon the theories of climate , which would account for all past changes of temperature by changes in the relative position of land and xvater on the earth 's surface ; " and I think that all geologists will agree with this remark , and feel that if the possibility of a change in the position of the axis of rotation of the crust of the earth were once admitted , it would smooth over many ? difficulties they now encounter . That some such change is indeed taking place at the present moment may not unreasonably be inferred from the observations of the Astronomer Royal , who , in his Report to the Board of Visitors for 186 l , makes use of the following language , though " only for the sake of embodying his description of the observed facts , ' as he refers the discrepancies noticed to " some peculiarity of the instrument ... . . The Transit Circle and Collimators still present those appearances of agreement between themselves and of change with respect to the stars which seem explicable only on one of two suppositions-that the ground itself shifts with respect to the general Earth , or that the Axis of Rotation changes its position . " .
112588
3701662
On the Action of Trichloride of Phosphorus on the Salts of the Aromatic Monamines
54
62
1,866
15
Proceedings of the Royal Society of London
A. W. Hofmann
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0018
null
proceedings
1,860
1,850
1,800
8
142
3,624
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112588
10.1098/rspl.1866.0018
http://www.jstor.org/stable/112588
null
null
Chemistry 2
91.345669
Fluid Dynamics
3.294846
Chemistry
[ -44.836204528808594, -59.395896911621094 ]
I. " On the Action of Trichloride of Phosphorus on the Salts of the Aromatic Monamines . " By A. W. IIOFMANN , LL. D. , F.1.S . , &c. Received March 3 , 1866 . The starting-point of the following experiments was an accidental observation . Whilst investigating the chlorine- , bromine- , and nitro-derivatives of aniline , I had prepared a large quantity of phenylacetamide by the action of chloride of acetyl on aniline . From the hydrochlorate of aniline , abundantly produced as a by-product in this reaction , the aniline was recovered by treating the mother-liquors with hydrate of sodium . During the distillation , after the greater part of the aniline had passed over and collected in the receiver , a tenacious oily fluid began to come over , adhering to the tube of the condenser and gradually becoming a crystalline mass . It was easily purified by washing with cold , and crystallization from hot alcohol . Beautiful white leafy crystals were thus obtained , fusible at 137 ? , and volatile without decomposition at a temperature beyond the range of the mercury-thermometer . These crystals are almost insoluble in water , difficultly soluble in cold , but soluble in hot alcohol , and also soluble in ether . The solutions are neutral . In acids the crystals are also easily soluble ; an alkali precipitates the original substance unaltered frora the solutions . The hydrochloric-acid solution yields , with tetrachloride of platinum , a difficultly soluble crystalline precipitate . The new substance thus exhibits the deportment of a well-characterized base . Its composition was readily determined by combustion with oxide of copper , the analytical results pointing unequivocally to the formula C7 71 N as the simplest atomic expression for the new body . But the whole behaviour of the substance , and more especially its transformation , by means of concentrated sulphuric acid , into aniline and acetic acid , leave no doubt that the above expression must be doubled , and that the new base is repre , sented by the formula Cl I-1 N2 . This formula was confirmed by the analysis of the platinum-salt already mentioned , and that of the nitrate which separates from the solution as an oily fluid , gradually changing to a beautiful crystalline compound ; the former contains 2(C1 11 N , IIC1 ) , Pt *C1 , the latter C , l Hi1 N , , HN03 . Whence is this body derived ? and how is its formula to be interpreted ? An answer to these questions was furnished by examining the chloride of acetyl employed in preparing the phenylacetamide . When on distilling the chloride the principal product had passed over , the thermometer gra* Pt=198 . dually rose from 55 ? to 78 ? . The last portion which came over was pure trichloride of phosphorus . It was obvious that this substance must have played a part in the formation of the new compound . I therefore submitted phenylacetamide to the action of trichloride of phosphorus . The new body was formed , but in very unsatisfactory quantity . The result of the experiment was essentially different when phenylacetamide and aniline in varying proportions were jointly submitted to the action of trichloride of phosphorus . The amount of substance obtained varied with the composition of the mixture , and appeared greatest when the mixture was made in the proportion of one part of trichlloride of phosphorus , two parts of aniline , and three parts of phenylacetamide . Hence the reaction had taken place according to the following equation : 3 C6 7N+3 C,8 H NO + PC3 =3 C14 H14 N2 + 113 PO3 +3 HC1 . Perfectly similar results were obtained when a proportionate quantity of hydrochlorate of aniline was employed instead of aniline in this experiment . The idea naturally presented itself to produce the same result without taking the trouble of preparing and purifying the phenylacetamide by including its preparation in the very process of forming the new compound . For this purpose 6 molecules of aniline were added to 3 molecules of chloride of acetyl , and the dense liquid thus 'obtained mixed with 1 molecule of trichloride of phosphorus . The result could not have been better : 6C , , N +3C13 OCIl+PCI3=3 C3 , HI N , + H3 P 3+ 6 HC1 . A simple additional step and the true mode of preparing the substance , and with it the general method for the production of an endless variety of analogous bodies , was found . Evidently it was not even necessary to prepare the chloride of acetyl separately . The new body must be as easily obtained by the direct action of trichloride of phosphorus on aniline and acetic acid . The mixture had only to be made in such a manner that , after transforming the acetic acid into chloride of acetyl , there was a sufficient amount of trichloride of phosphorus left to perform the rest of the work . In this case , therefore , 6 molecules of aniline and 3 molecules of acetic acid had to be added to 2 inolecules of trichloride of phosphorus , 6C , H , N +3 CH2 0 , +2PC13 -3C 11 , N + , 2 13 P03 6HC1 . The reaction is violent , and the operation must be performed with care . The substances are mixed according to the above equation . For this purpose three parts by weight of aniline are added to one part of acetic acid and into the mixture surrounded by cold water two parts of trichioride of phosphorus are slowly poured ; in which proportion the latter compound is in slight excess . The tenacious fluid thus obtained is then heated for a couple of hours to 160 ? . On cooling , it solidifies to a hard , friable , translucent , resinous mass of a light-brown colour , which dissolves in boiling water almost without residue , leaving only traces of an amorphous yellow substance containing phosphorus behind . The clear filtered solution , after cooling , yields , on the addition of soda , a white crystalline precipitate , which requires only to be washed and recrystallized from alcohol . The foregoing equations give a pretty clear idea of the qualitative and quantitative nature of the experiment , but they do not afford us an insight into the true mechanism of the reaction . This , nevertheless , is a very simple one . Trichloride of phosphorus acts water-generating and waterwithdrawing . The oxygen required for this purpose is supplied by the pheliylacetamide ; as , however , the molecule of this compound contains but one atom of hydrogen belonging to the original ammonia skeleton , a molecule of aniline is required in addition to supply the second atom of hydrogen . In this manner a diamine is formed , in which two atoms of the hydrogen of the double ammonia type are replaced by two univalent phenyl-residues , and three of the remaining hydrogen atoms by the trivalent group C2 H1 , to which the term ethenyl * may for the present be applied . The new body would thus become ethenyldiphenyldiamine , the formation of which in the most simple form would depend upon the removal of 1 mol . of water from 1 mol . of phenylacetamide and 1 mol . of aniline . C , , j > N -N N==1 + ( C6 HA )2 N , . Hi 3H1 I-I H3 I was anxious to test this assumption by experiment . At 100 ? iodide of ethyl has no action on ethenyldiphenyldiamine , but at about 150 ? the two bodies react on one another . The mixture , after being heated for five or six hours , yielded , upon cooling , beautiful crystals of an iodide . By treatment with chloride of silver this iodide was converted into the corresponding chloride , and then into the platinum-salt . Analysis of this salt showed that the ethyl group had been once taken up . On the addition of caustic soda the corresponding base was separated . It is a thick oily fluid , which , when shaken with water , does not impart to it the slightest alkaline reaction . By renewed treatment with iodide of ethyl an iodide , it is true , was separated , but it was proved on examination that the ethyl group had not been assimilated a second time . In the sense of the above assumption , this nevertheless ought to have taken place . The experiment was therefore repeated with iodide of methyl which is well known to act much more powerfully than the ethyl-compound . This body attacks the ethylated base even at 100 ? . The iodide thus obtained , when decomposed by oxide of silver , yielded a strongly lalkaline liquid , whence quantivalence of the residuary group again increases , the groups becoming quadri . valent and quintivalent , and acquiring the terminations in and inyl , &c. According to this principle the following names are formed : Methane , ( C H4 )o Sextane , ( C6 H14 ) ? Ethane , ( C2 He )o Septane , ( C , H116 ) Propane , ( C3 H8 )o Octane , ( C8 HI18 ) Quartane , ( C4 Hio)0 Nonane , ( C9 IH20 ) Quintane , ( C5 H112 ) Decane , ( CIo H22 ) ? And further : Methane , ( C H1)J 'Ethane , ( C20 1)0 Propane , ( Ca H8 ) ? Quartane , ( I H10 ) ? Methyl , ( C H13 ) Ethyl . ( C2 H5 ) ' Propyl , ( C H ) ' Quartyl , ( C4 1 , ) ' Methene , ( C 12 ) " Ethene , ( C21 ) " Propene , ( C311H ) " Quartene , ( C4s ) " Methenyl , ( C H ) " ' Ethenyl , ( C2 ) " ' Propenyl , ( Ca { O ) " ' Quartenyl , ( C4H ) " ' Ethine , ( C2 H2)iV Propine , ( C3 H)iv Quartine , ( C 116)iV Ethinyl , ( C0 I7 Propinyl , ( C 1H3 ) V Quartinyl , ( 04 H)V Propone , ( C3 H2 ) , i Quartone , ( 04 4)vi Proponyl , ( Ca I{)vii Quartonyl , ( C4 113)ii Quartune , ( O4 I2)viii Quartunyl , ( C4 H )i This is not the place to develope this subject further . The short notice I have given must suffice . A superficial examination of the system shows , however , how large a number of groups of atoms may be clearly and succinctly expressed in it . It appeared convenient to submit the plan to a provisional test by framing some of the names required for the substances which were furnished by the above experiments . Bodies containing oxygen may be as simply nominated according to this plan . The acid derived from ethylic alcohol is ethoxylic acid ( acetic acid ) , the first acid corresponding to ethenic alcohol would be etho.xenic acid ( glycolic acid ) , the second being ethdioxenic acid ( oxalic acid ) . We speak of the oxylic , oxenic , and dioxenic acids of a series , of the quartane series , for inlstance , and any one would understand that by these expressions are meant butyric , butylactic , and succinic acids . it was at once inferred that the methyl group had been added to the ethyl group already present in the substance . This conclusion was amply corroborated by the analysis of the platinum-salt precipitated from the liquid . By this experiment the nature of ethenyldiphenyldiamine is most satistorily elucidated . The action of iodide of ethyl had converted this base into the tertiary diamine ethenylethyldiphenyldiamine , ( C2 H3 ) ; ( C2115 ) N2 ; ( C6 11)2 J the latter , under the influence of iodide of methyl , yielding the compound [ ( C2 113 ) " ' ( C2 11 ) ( C6 Ha ) > N2 ] ( C H3 ) } , which is soluble in water with a strongly-marked alkaline reaction . The stability of ethenyldiphenyldiamine is remarkable . As I have already mentioned , this base distils at a very high temperature without decomposition . It is moreover scarcely attacked by fision with hydrate of potassium . Concentrated sulphuric acid , on the other hand , decomposes it easily . When gently heated , the solution of ethenyldiphenyldiamine in sulphuric acid evolves acetic acid , and , on addition of water , the slightly-coloured liquid solidifies to a white crystalline mass of sulphanilic acid , ( 0 211)2 }H 11C2 r0C io5 ( C s)2 N 2+2H SO= 3 o+2 HN 83 RH H It need scarcely be mentioned that , by reactions similar to that of trichloride of phosphorus on acetate of aniline , an almost endless variety of new compounds may be obtained . By changing the acid , or base , or both , a series of substances is formed , the composition of which in each case is fixed in advance by theory . I have worked only very little in this direction . Toluidine acts in a manner precisely similar to that of aniline . The base formed can scarcely be distinguished from the phenyl base . Analysis of the platinum-salt has led to the formula ( C2 ) " ' ) 16 I,18 N2= ( C , H7)2 N2 . With naphthylamine the reaction is less smooth . The product obtained by acting with 1 molecule of trichloride of phosphorus on 3 molecules of chloride of acetyl and 6 molecules of naphthylamine , was an unenjoyably viscous scarcely crystalline mass which retained , after repeated solution and precipitation , its amorphous character . An analysis of the platinumsalt led , however , to the formula ( C2 1H3 ) " C22 1 N2= ( CO 117)2 N2 . toluidine , and naphthylamine being primary monamines , it seemed of interest also to extend the examination to a secondary one . For this purpose I selected diphenylamine . When a mixture of diphenylamine and phenylacetamide , in the proportion of their molecular weights , was submitted to the action of trichloride of phosphorus , the reaction took place in the ordinary way , but the mass precipitated from the solution of the chloride by ammonia could not be crystallized . It had therefore to be analyzed as platinum-salt . Determination of the platinum as well as combustion showed , however , that the expected ethenyltriphenyldiacmine had been formed , C2 1130 C6 1-5 N ( C2 13 ) " C , H1 N+C , H+ N= 0+ ( ( , . ) , 2 N.2 , II~J ( C( J-J- ) J An entirely unexpected result , on the other hand , was obtained by the action of triclloride of phosphorus on a mixture of acetic acid and methylaniline . Working , as I did , exclusively with a secondary monamine , I had expected to see the reaction take place according to the following equation:rCi3 Oc io-1 ( C2 113 ) " 3 C6JI , N+2 }0=2 1O +(C H3)3 N3 . L IH ( C 115 J_3 But this was not the case ; the action was found to have been very irregular ; and amongst the products a chloride was observed , the base of which , when liberated by oxide of silver , dissolved in water with an alkaline reaction . When analyzed in the form of a platinum salt , this body proved to be ethenyldiphenyldiamlinie , which had twice appropriated the methyl-group , having the composition [ ( C2 H , ) " ( C , Hii , ) ( C H3 ) N , ] C HI , In this case evidently chloride of methyl had been eliminated from one of the molecules of mietliylaniline , which , acting on the ethenyldiphenylmethyldiatnine , had given rise to the formation of the chloride corresponding to the above-mentioned oxide , 2[(C , H1 ) ( C H13 ) HN ] + C2 I3 0 C1= -110 + [ ( C , I- , ) ' " ( C , II ) , ( C HI ) N , ] ( C 11 ) Cl. A few experiments made with the derivatives of valeric and benzoic acids are still to be mentioned . Quintenyldiphenyldiamine.-For the preparation of this substance , 3 molecules of valeric acid were miixed with 6 molecules of aniline , and to the liquid , after cooling , 2 molecules of trichloride of phosphorus were added . This mixture , on being submitted for a couple of hours to a temperature of 150 ? , yielded a viscous mass soluble in water . Fromn the solution hydrate of sodium precipitated a crystalline base almost insoluble in water , which was recrystallized from alcohol . This substance fused at 1 11 ? . The com bustion of the body and the analysis of its platinum-salt , which crystallized in rhombic plates difficultly soluble in water and almost insoluble in alcohol , led to the formula ( C , H1 ) " ' CG7 -20 N2 =(C6 HJ ) N2 . H Benzyldiphenyldiamine.-By substituting benzoic acid for valeric acid in the reaction just described , the corresponding benzyl-compound is obtained . I have prepared this substance by the action of 1 molecule of trichloride of phosphorus on a mixture of 3 molecules of phenylbenzamide and 3 molecules of hydrochlorate of aniline . The reaction takes place in the ordinary way . The product is a very weak base crystallizing in fine silky needles . The hydrochlorate forms thin brilliant plates difficultly soluble in water , which upon re-crystallization lose their acid . The analysis led to the formula ( C7 )'1 C19 Uo16 N2=(C6 HUE , )2 > N2 . HJ This compound has been already observed by Gerhardt . He obtained it whilst examining the action of pentachloride of phosphorus on the amides , the last experiments which he performed before his death . A short notice of this investigation , found after his death , has been published by M. Cahours * . The phenyl-compounds of the acetic and valeric groups above described are naturally linked with a compound which several years ago I procured by an essentially different reaction . This substance , which at the time I described under the name of formyldiphenyldiaminet , but to which , in accordance with my present ideas on nomenclature , I would give the name methenyldiphenyldiamine , is obtained by the action of chloroform on aniline ; its relation to the compounds before mentioned is seen by a glance at the following formule:(C T1 ) ' " Methenyldiphenyldiamine , C13 H1 N2= ( C6 T1s ) N2 . ( C , H1 Ethenyldiphenyldiamine , C , , IH , N= ( C , HI)2 N , . HJ ( C5 J1 ) " ) Quintenyldiphenyldiamine , C7 HI0 N2 =(C6 II)2 N , . It seemed worth while to establish by a special experiment the analogy of methenyldiphenyldiamine , obtained in so different a reaction , with the substances just described . For this purpose I submitted phenylform* Ann. Ch. Phys. [ 3 ] , vol. liii . p. 302 . t Proceedings of the Royal Society , vol. ix . p. 229 . 61 amide* to the action of a mixture of aniline and trichloride of phosphorus . The result proved that the methenyl-compound can be thus prepared even more easily than by means of chloroform . In conclusion , the relation must be mentioned which the compounds just described hear to the base obtained by Professor Strecker t , when acting with gaseous hydrochloric acid on acetamide , The body thus formed is C2 H , N2 ( C2 3)i } N2 , H3 ~ , and has been called acediamine , for which name , in accordance with the proposed nomenclature , I would now substitute the term ethenyldiamine . When compared with the analogous aniline-compound , the very slight stability of acediamine , which splits up with the greatest facility into acetic acid and ammonia , deserves to be noticed . A quintenyldiamine , corresponding to the quintenyldiphenyldiamine , has not as yet been prepared . Methenyldiamine , on the other hand , is known , although the compound which I have in view has scarcely been looked upon as such . The body in question is no other than cyanide of ammonium . ( C I[ ) " ' t ) Methenyl(C I)m } Methenyldiamine ( C H it Methenyl(C H)'N ( Cyanide of ammonium ) dieny ( Ce 5)2 HJ diamine H The facility with which this substance decomposes is well known ; amongst the productsformic acid and ammonia are invariably found . It is further known that by heating ammonia with chloroform ( trichloride of methenyl ) , cyanide of ammonium is formed , a reaction which is perfectly similar to that by which the analogous phenyl-base was originally obtained in the corresponding experiment with aniline . In conclusion , I beg to thank Messrs. Tingle and Fischer for their valuable assistance during the performance of the experiments described .
112589
3701662
Notice of a Zone of Spots on the Sun
63
70
1,866
15
Proceedings of the Royal Society of London
John Phillips
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0019
null
proceedings
1,860
1,850
1,800
8
174
3,950
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112589
10.1098/rspl.1866.0019
http://www.jstor.org/stable/112589
null
null
Astronomy
45.39217
Optics
26.544189
Astronomy
[ 74.14315795898438, 31.21519660949707 ]
II . " Notice of a Zone of Spots on the Sun . " By JOHN PHILLIPS , M.A. , LL. D. , F.R.S. , Professor of Geology in the University of Oxford . Received March 22 , 1866 . During the latter half of February and the first half of March , spots of extremely varied character have appeared on the sun , and have been seen with great distinctness , in good observing weather , through the whole or parts of two semi-rotations . On the 13th of February , at 10h 25 ' , four spots were visible on the disk , in the situations marked Z , A , B , C in the diagram No. 1 . In that diagram the apparent course of the sun 's equator is Diagram No. 1.\3 marked by the curved line e , and the pole of rotation at P. Thus the four spots indicated for observation being all on the same side of the sun 's equator , and all within the latitude of 10 ? , constitute a zone of spots . Since that date a fifth spot , D , still in the same zone , has appeared , following C. Of these Z was about to disappear ; its reappearance was noted , and several remarkable changes in form were observed while it traversed half the disk , till its contraction to a black speck 1000 miles in diameter , after which it was obliterated . The spot B had advanced some distance on the disk , and was followed till the 2i st of February , when it approached the edge , with indications of being a shallow concavity . It was not observed to reappear . The spots A and C require longer notice , both on account of their persistence through more than a rotation-period , and because of the remarkable changes which they have undergone . The spot D is now under observation . The spot A , visible from the 4th to the 16th of February , and again reappearing early in March , was solitary , and approximately round , measuring , on February 10 , about 23,000 miles across the penumbra , and about 8000 across the umbra . It had a clear brown tint over the whole penumbra , the body of the sun appearing fairly white , and a deeper brown tint over part of the umbra , the remaining and larger space of the umbra being black . The penumbral space was marked with the broken structure represented in a former communication* . The edges of the umbra and penumbra were much broken , the former running out into a sharp point on the apparent left , and including a lighter brown space . Except in this part , the dark umbra was uniformly and equally distant from the penumbral border , so that it offered an excellent object , large enough and distinct enough to be employed with confidence as a test of the depth of the umbra beneatli the luminous photosphere . In a former communication I assigned to an umbra of good figure , carefully observed , a depth of only 300 milest . Since then M. Chacornac+ has given the depth of 400 miles as an approach to average , though in some cases 1000 miles might be nearer . That the spots are most frequently sunk below the photosphere , as Wilson long since asserted , can no longer be doubted , since Mr. De la Rue , Mr. Stewart , and Mr. Loewy have recorded , after many measures of photographs taken at Kew , as the general result that the interior parts of the solar spot are sunk below the general surface ? . . The spot now under consideration approached the edge of the disk on the 15th of February , when the umbra seemed nearly bridged across by a lighter part , and was perceptibly but very slightly nearer to the following , or left-hand side . The reappearance of this spot was anxiously looked for . It came into view on the morning of March 3 , having when observed passed the limb about 6§ 16 ' . Its appearance was sketched on this occasion , and again on successive days to the 14th of March . Its apparent magnitude was diminished , but the main features were less altered than is usual with sunspots . The umbra still appeared in such relation to the penumbral border as to confirm the opinion of its being but very little depressed below the photosphere . Remarkable changes happened between the 7th and 10th of March . On the 8th two broad penumbral extensions appeared ; on the 9th these were separated into two detached masses , and much altered in figure . Diagram No. 2 . The path of spot A in February and March . The great spot , or rather aggregation of spots , marked C , was observed from the 13th to the 24th of February , as often as good opportunities occurred in the extremely variable weather . When fully expanded , about the 17th , 18th , and 19th of February , it measured about 12 ? on the surface of the sun , and occupied a space about 100,000 miles long , lying not quite parallel to his equator , and including forty or more black , dark , and dusky umbral tracts , in a cormplicated penumbral area . The definition was often excellent , so as to show the granular surface of the photosphere with more than ordinary distinctness . The same fine brown tint already referred to was observed in the penumbral spaces , and there was every gradation of depth in this tint observable in the many specks and spots , till in a few only it seemed to be black . The penumbral tracts were plainly broken up into a kind of network of granllation ; and the largest spot , chosen for special study , threw out long black digitations into the surrounding granulated space of the penumbra , like slits in a solid substance , 1000 or 2000 miles in length . These characters of the largest spot in the group C became very prominent on the 19th of February , and were accompanied by others of an unusual character , which seem to deserve special attention in the question of the nature and history of these black spaces . In the drawing for this date these appearances are sketched with a power of 135 . The spot was somewhat rhomboidal , the extreme length from angle to angle being about 15,000 miles , the least breadth about 4500 . On the right the boundary was gently convex ; parallel to it was a bright facular tract of uniform breadth ; this was margined on the right by a nearly continuous very narrow black band , 17,500 miles long , extending in both directions beyond the spot , and slightly ramose in the ( apparently ) upper part . Parallel to this again was a curiously interrupted series of black angularly bent sharp cuts , ending upwards in a larger subdigitated mass , near which were some other small spots , forming broken chains , which turned off in curves to the right for about 40,000 miles ( P1 . II . fig. 7 ) . On the 20th of February the appearances had changed to those represented in another sketch ( P1 . II . fig. 8 ) , where the great spot , something reduced in magnitude and altered in figure , shows very long digitations on all sides ; the facular space on the right is broader ; the long very narrow black band shows two internal extensions ; the outer crested ridge has gathered itself into a shorter figure , 10,000 miles long , and has lost the character of angular tegulation which was so remarkable on the 19th. . On the 21st the spot had approached enough toward the limb to undergo some apparent change of general figure , by contraction perpendicular to the edge ; the facular space on the right was entirely free from the narrow curved black divisional band ; and the summit of the outer broader band was bent away from the great spot , to which it had been parallel ( PI . II . fig. 9 ) . The disappearance of the spot amidst large elevated bright faculm and depressed broader shaded tracts , was sketched on the 24th of February . Reappearing with similar splendid companion ridges of mountainous clouds , but much reduced in size , and altered in every part , it was observed again from the 12th to the 17th of March , after which the weather allowed no further opportunity . Two sets of drawings of this remarkable spot are presented to show its growth , development , and decay ( P1 . II . figs. 7 , 8 , 9 , and 10 , 11 , 12 ) . The apparent path on the sun 's disk is given for each period of appearance the two paths differing by reason of the change in the apparent place of the sun 's equator ( see Diagram No. 3 ) . Diagram No. 3 . 4 But few examples occur of such large penumbral tracts grouped about so many dark and half-darkened umbrm . On the sun they occupied , as already stated , a tract about 12 ? in length , not quite parallel to the equator ; and may be compared to some of those which are most conspicuous in Mr. Carrington 's plates . From what has been observed , it appears that , in a given zone of spots , not only are the aspects of the particular spots much diversified , but further , that the changes to which they are subject offer much variety . These circumstances seem to point to particular local conditions as the cause of the diversity of appearance , though it may be possible to refer to other influences the frequency of their occurrence , if not the fact of their occurring at all . The five spots now under review lie within an arc of longitude of 205 ? , leaving 155 ? in which as yet no spot has lately been s ? .en . In 1864 , during the months of March and April , a zone of spots , also five in number , and on the same side of the equator , was contained within an arc of longitude of 243 ? , leaving 117 ? at that time free from spots . There was then within the same arc of 243 ? a pair of spots in about the same latitude , but in the opposite hemisphere . Taking these into account , the average of the arcs of longitude between the spots was about 49 ? . In the case of the spots lately passing it was 51 ? . Twenty-six revolutions would have brought the middle of that zone of activity of 1864 to nearly the same place on the sun 's disk , as the group now under consideration . To whatever cause we may ascribe the fact of the breakixng out of these [ Mar. 22 , spots , there would appear reason for expectation that spots of like character may be expected to recur again in the same parts of the sun 's surface . In the great work of Mr. Carrington we find several examples of the appearance of new spots in nearly the same places as those which had been so occupied before . Those who think with M. Chacornac that sun-spots are due to volcanic eruptions , and regard their changes of appearance as effects of the displacement of solid and gaseous bodies about the region of disturbance , must naturally look for repetitions of these phenomena in the same parts of the solar surface . The greater frequency of spots between the parallels of 10 ? and 30 ? lat. N. and S. , the comparative rarity of them on the equator , and the almost entire absence of them from the circumpolar regions is well established . If we take the data from Mr. Carrington 's register and suppose in all 1000 spots to be observed , 178 will be found between the parallels of 0 ? and 10 ? from the equator , 450 between 10 ? and 20 ? , 324 between 20 ? and 30 ? , and 48 above 30 ? . The proportionate numbers for the northern and southern hemispheres are 450 in North latitude , 550 in South latitude . If now we inquire , by the aid of the same invaluable book , as to the relative frequency of spots in different longitudes , we shall obtain a result of considerable interest in reference to the qcuestion of the place of the eruptions . Mr. Carrington has registered his observations through 99 rotations , and has arranged them in groups which can be tabulated for longitude . Assumring the rotation-period to be exact enough for fixing the longitudes in the course of seven years and 142 days , we may represent the relative frequencv of the spots on different meridians as follows : 00 Longitude 10 to 20 ... . 320 maximum ; G , 60 to 70 ... . 220 mini-mui m ; , , 100 to 110 ... . 313 maximum , , 60 to 170 ... . 250 mininmumn ; , 190 to 200 ... . 366 maximum ' 300 to 310 ... . 173 minimumn ; showing three maxima at intervals of 90 ? , 90 ? , and 180 ? , and three minima at intervals of 1000 , 1400 , and 120 ? . Or if we take the eircumference of the sun in three meridional compartments of 120 ? each , and suppose ] 000 spots in all , we shall find 0 to 120 ... . 357 120 to 240 ... . 368 240 to 360 ... . 274 I am at present of opinion that this result may be trust ( so far as to show that certain tracts of the sun 's surface are more liable to eruption than other tracts , by reason of local peculiarity only . 67 Luminosity of the Sun . Attentive observation shows the light of the sun to be feeblest toward the edges of the disk , strongest about the centre . By M. Chacornac 's measure the ratio of the central to the marginal light is 100 to 45 . Looking directly on the central regions , the light is found to be much the brightest on the apparent summits of the undulations of the photosphere ( " ricegrains " ) ; and looking to the limb , it is the facule which are the brightest parts . In each case it is the outermost parts of the photosphere which are the brightest , and it is the innermost parts which are the darkest . The depth of shade appears to be in direct proportion to the depth below the outer surface of the photosphere . It appears to me that such appearances would follow naturally from the hypothesis mentioned in my first communication on this subject * . The hypothesis is that the lowest parts of the umbral spaces yield the least refrangible and least luminous rays , such as belong to the space about the red end of the spectrum . These spaces may not be black , not even very dark , except by comparison with the brilliant spaces around ; where the rays from them pass into the photosphere , they heat it , as the dark rays separated by sulphuret of carbon in Tyndall 's experiment heat the platinum foil , and other solid bodies . Bodies thus heated emit new rays according to their nature ; the solar photosphere is of such a nature as to send to us the miugled pencils which we receive ; the principal effect of this kind being at a maximum on the outermost layer . The effect of this will be to cause streams of the most luminous rays from the most elevated parts of the photosphere , which will be seen directly in front , about the sun 's centre , while toward the edges the sides of the undulations alone will be seen , and the rays which they yield will be less luminous the only parts which are there very bright being the high ridges of the facule . Another view has presented itself to me . If we admit the depressed part to be the body of the sun disclosed from below the luminous envelope , we may suppose its darkness to be due simply to radiation . For however hot the sun may be , if its composition be like that of the earth , the fused parts would be cooled and darkened at the surface where it may be uncovered-very much darkened where the exposure is complete ( the umbra ) , partially so where the envelope is not wholly removed ( the penumbra ) . It might be some test of this view , if the hourly changes of the umbra , immediately after its first appearance , could be accurately noted in respect of the degree of darkness as well as of the change of form . The umbra ought to grow darker and darker , never lighter and lighter , except by the overspreading of photosphere , which would be indicated independently by changes on the penumbral area . From what I have seen in the course of these observations , I infer that the study of the physical condition of the solar spots cannot be regarded as likely to yield data of sufficient weight , if it do not include determina* Proc. Roy . Soc. January 1865 . [ Mar. 22 , tions at short intervals , as twice a day for the whole penumbral outline , and once an hour for selected critical parts of the umbra . EXPLANATION OF PLATE II . [ The figures are all drawn to represent the objects as they appeared in a 6-inch achromatic furnished with the glass mirror set to reflect the rays in the equatorial plane to the westward . The motion of the spot is from left to right . ] Fig. 1 . Appearance of the spot A , nearly on the central meridian , on Feb. 10th , 1866 , at 11h 15im . The darkest part of the umbra was to the right ; on the left a sharp excurrent part like a fissure ; between this and the larger and darker part was a lighter brown tract . Small dots on the penumbra in the upper part to the left . Diameter 23,000 miles . Fig. 2 . First sketch of the spot A after its reappearance , March 5th , 10oh 30 . The long excurrent parts at the extremities of the elliptical figure ( elliptical by reason of the proximity of the spot to the edge of the disk ) are frequent appearances in this position of the spots . This figure is rather too small in proportion to 4 , 5 , and 6 . Fig. 3 . Spot A , further on the disk . The figure is rather too small . Note the peculiar shapes of the small fissure-like extensions on the left . March 6th , 211 30 " . Fig. 4 . Spot A , still further on the disk , March 7th , 10h Om . The ramifications from the umbra have changed in appearance . Fig. 5 . Spot A. near the central meridian , March 8th , 12h 30 " . The two extensions of the penumbra on the left have come into sight since yesterday . Note the little dot at their common origin , and , directed towards it , the longest of the excurrent umbral fissures . Fig. 6 . Spot A , March 9th , 121 0o " . Here the excurrent penumbral tracts are foundc to be separated from the spot , and from each other , and changed in directioni The umbra is much altered , and has a deep emargination , in place , apparently , of a small white speck , seen in fig. 5 . Note also a black speck on the right upper edge of the umbra . Fig. 7 . Spot C , the largest umbral tract with its border on the right , Feb. 19th , 10h 45"1 . On account of the remarkable aspect which the umbra wore on this occasion , it was drawn repeatedly with great care . Note in particular the digitations of the large umbra , the broad facular space to the right , and the parallel very narrow , interrupted , and tegulated umbral bands , which are part of a system of interrupted small dark tracts , traceable through nearly all the length of the penumbra , which on this occasion was about 100,000 miles from end to end . The umbra itself measured about 15,000 miles between the extremities of the digitations . Fig. 8 . The same parts as they appeared on Feb. 20th , 10h 20m . The general figure of the umbra is changed ; the long parallel narrow black space , and the broader tract on the outside of it are greatly altered ; the latter , turning away from the umbra , appears to have gathered into itself the detached spots which appear in fig. 7 , and to have lost the angular tegulation which then was conspicuous . Fig. 9 . In this figure the approach toward the edge of the sun is sensible in the elongation of the large umbra and its com panion . Feb. 21st , 21 30Om . Fig. 10 shows the reappearance of this spot C , near the edge , with a divided umbral tract , of different shades of darkness ; the whole figure compressed elliptically by proximity to the edge . March 12th , 12h 10 . Fig. 11 . The same spot after it had proceeded on the disk , so as to allow of all parts being seen in their true proportions . March l3th , 2'1 30m . The change of figure in the whole penumbral space , and in the darkest parts , is so great that it is difficult to be assured of the identity of any one point now visible with the appearance shown on ally occasion in February . Yet , in fact , on searching carefully the neighbouring tracts of photosphere , we can discern what appear to be traces of the spaces occupied by the old penumbra . This important observation was made , not by myself only , but also by friends who were quite unaware of the interesting changes of form which had occurred . Fig. 12 . March 14th , I11 30m . HIere the spot is seen further modified ; gathered up into a smaller and more regular shape , with a deep slit through the penumlbra into the umbra ; the detached penumbra on the left was lost after a further day 's motion .
112590
3701662
On Uniform Rotation. [Abstract]
71
73
1,866
15
Proceedings of the Royal Society of London
C. W. Siemens
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
3
24
1,407
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112590
null
http://www.jstor.org/stable/112590
null
108,958
Measurement
65.765419
Fluid Dynamics
26.139017
Measurement
[ 42.28742599487305, -12.62064266204834 ]
I. " On Uniform Rotation . " By C. W. SIEMENS , F.R.S. Received March 10 , 1866 . ( Abstract . ) The paper sets out with an inquiry into the conditions of the conical pendulum as a means of obtaining uniform rotation . This instrument , as applied by Watt to regulate the velocity of his steam-engines , is shown to be defective , -first , because the regulated position of the valve depends upon the angular position of the pendulums , and therefore upon the velocity of rotation , which must be permanently changed in order to effect an adjustment of the valve ; and secondly , because when the balance between force and resistance of the engine at a given velocity is disturbed , the angular position of the pendulums will not change until a power has been created in them , through acceleration of the engine , sufficient to overcome the mechanical resistance of the valve , giving rise to a series of fluctuations before a balance between the power and resistance of the engine is reestablished . These defects in Watt 's centrifugal governor are shown to be obviated in the chronometric governor , an instrument which was proposed by the author of the paper twenty-three years ago , and which consists of a conical pendulum proceeding at a uniform angle of rotation , and therefore at uniform speed , which is made to act upon the regulating-valve by means of a differential motion between itself and the engine to be regulated , which latter has to accommodate itself to the rotations imposed by the independent pendulum . The differential-motion wheels are taken advantage of for imparting independent drivingor sustaining-power to the pendulum ; and a constancy of the angle of rotation , notwithstanding unavoidable fluctuations in the sustaining-power , is secured ( within certain limits ) by calling into play a break , or fluid resistance , at the moment when the angle of rotation reaches a maximum , which maximum position is perpetuated by increasing the sustaining-power beyond what is strictly necessary to overcome the ordinary resistance of the pendulum . The chronometric governor is used by the Astronomer Royal to regulate the motion of the large equatorial telescope and recording apparatus at Greenwich , in which application a very high degree of regularity is attained ; but the instrument proved to be too delicate in its adjustments for ordinary steam-engine use . After a short allusion to M. Foucault 's governor , the paper enters upon the description of a new apparatus which the writer has imagined for obtaining uniform rotation , notwithstanding great variations in the drivingpower , and which consists , in the main , of a parabolic cup , open at top and bottom and mounted upon a vertical axis , which cup dips with its smaller opening into a liquid contained within a casing completely enclosing the cup . It is shown that a certain angular velocity of the cup will raise the liquid ( entering from below ) in a parabolic curve to its upper edge or brim , and that a very slight increase of the velocity will cause actual overflow , in the form of a sheet of liquid , which , being raised and projected against the sides of the outer chamber , descends to the bath below , whence fresh liquid continually enters the cup . Without the overflow scarcely any power is required to maintain the cup , with the liquid it contains , in motion ; but the moment an overflow ensues , a considerable amount of power is absorbed in raising and projecting a continuous stream of the liquid , whereby further acceleration is prevented , and nearly uniform velocity is the result . When absolute uniformity is required , the cup is not fixed upon the rotating axis , but is suspended from it by a spiral spring , which not only supports its weight , but also transmits the driving-power by its torsional moment . The cup is guided in the centre upon a helical surface , which arrangement has for its result that an increase of resistance or of driving-power produces an increased torsional action of the spring , and with it an automatic descent of the cup , sufficient to make up for the thickness of overflow required to effect the readjustment between power and resistance , without permanent increase of angular velocity . It is shown that the density of the liquid exercises no influence upon the velocity of the cup , which velocity is expressed by the following formula , p2 n-2r7r in which n signifies the number of revolutions per second , h the height of liquid from the surface to the brim of cup , r the radius of the brim , and p the radius of lower orifice of cup ; only the rigidity of the spring must be greater when a comparatively dense liquid is employed . In order to test the principle of action here involved , Mr. Siemens has constructed a clock consisting of a galvanic battery , an electro-magnet , and his gyrometric cup , besides the necessary reducing-wheels and hands upon a dial face , which proceeds at a uniform rate , although the driving-power may be varied between wide limits , by the introduction of artificial resistances into the electrical circuit . The instrument appears , therefore , well calculated for regulating the speed of all kinds of philosophical apparatus , and also for obtaining synchronous rotations at different places for telegraphic purposes . One of its most interesting applications is embodied in the " Gyrometric Governor " for steam-engines , of which an illustration is given . This consists of a cup of 200 millinetres diameter and the same height , which is fixed upon its vertical axis of rotation , and is enclosed in an outer chamber , containing water in such quantity that the lower extremity of the cup dips below its surface . The upper edge of the rotating cup is , in this application , surrounded by a stationary ring armed with vertical vanes , by which the overflowing liquid is arrested and directed downward , causing it to fall through a space or zone which is traversed by a number of radial and vertical blades projecting from the external surface of the rotating cup , which , in striking the falling liquid , project it with considerable force against the sides of the outer vessel , at the expense of a corresponding retarding effect on the cup , increasing its regulating-power . The cup-spindle carries at its lower extremity a pinion , which gears into two planet-wheels at opposite points , which on their part gear into an inverted wheel surrounding the whole , which latter is fastened upon a vertical shaft in continuation of the cup-spindle , and is driven round by the engine in the opposite direction to the motion of the cup . The two intermediate or planet-wheels are attached to a rocking frame supported , but not fixed , upon the central axis , which wheels , in rotating upon their studs , are also free to follow the impulse of either the pinion or the inverted wheel to the extent of the differential motion arising between them . The rocking frame is connected to the regulating valve of the engine , and also to a weight suspended from a horizontal arm upon the valve-spindle , tending to open the valve and at the same time to accelerate the cup to the extent of the pressure produced between the teeth of the planet-wheels and the pinion , while the engine is constantly employed to raise the weight and to cut off the supply of steam . The result is that the engine has to conform absolutely to the regular motion imposed by the cup , which will be precisely the same when the engine is charged with its maximum or its minimum of resisting load . The paper shows that the action upon the valve must take place at the moment when the balance between the power and load of the engine is disturbed , and that the readjustment will be effected notwithstanding a resistance of the valve exceeding 100 kilogrammes-a result tending towards the attainment of several important objects .
112591
3701662
On a Fluorescent Substance, Resembling Quinine, in Animals; and on the Rate of Passage of Quinine into the Vascular and Nonvascular Textures of the Body
73
93
1,866
15
Proceedings of the Royal Society of London
H. Bence Jones|A. Dupr\#xE9;
fla
6.0.4
null
null
proceedings
1,860
1,850
1,800
21
450
10,627
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112591
null
http://www.jstor.org/stable/112591
null
null
Physiology
29.437222
Chemistry 2
21.870386
Physiology
[ -64.95606231689453, -20.668569564819336 ]
Professor Donders has carefully investigated the time in which atropine and Old Calabar bean begin and cease to act on the iris in man . A solution of atropine dropped upon the cornea began to act in fifteen minutes , and attained its maximum in from twenty to twenty-five minutes . In forty-two hours the pupil was rather smaller ; and even after thirteen days the pupil had not returned to its natural size . The solution of Calabar bean began to act in from five to ten minutes . It attained its maximum in from thirty to forty minutes . At the end of three hours it began to diminish , and its effect disappeared entirely in from two to four days . After continued applications of belladonna to the eye of a rabbit , it was thoroughly washed by a full current of water . The aqueous humour was then evacuated and brought into contact for a long time with the eye of a dog ( De Graefe injected the aqueous humour into the anterior chamber ) ; then a notable dilatation of the pupil was observed . As one part in 120,000 of water acts very energetically , the quantity must be very little that produced the dilatation of the pupil . When belladonna used internally produces the dilatation , the aqueous humour which is taken from the anterior chamber is inactive . Thirdly . The fluorescence that naturally occurs in different parts of the human body when no quinine had been taken before death was determined , in order that the effect of quinine on the fluorescence in the same parts might be estimated : The different parts were dried in a water-bath , and equal quantities of the dried substance were taken , amounting to 0'6 grain , that being the weight of the dry lens . The same method of extraction was followed . The solution was in all cases made up to twenty-five grains . Extract from per 100 litres . Cartilage fluoresced one 32nd of a grain of quinine to a litre. . =3'1 Nerves fluoresced a little more than one 64th of a grain of quinine to a litre ... ... ... ... ... ... ... ... ... ... ... . =1*6 Liver fluoresced a little more than one 64th of a grain of quinine to a litre ... ... ... ... ... ... ... . . =1 6 Kidney fluoresced a little more than one 64th of a grain of quinine to a litre ... ... ... ... . . =16 Lens fluoresced a little less than one 64th of a grain of quinine to a litre ... ... ... . * ... ..l ... ... ... 6 ... ... . 1 ' Lungs fluoresced one 128th to one 64th of a grain of quinine to a litre ... ... ... ... .=0 ... ... ... ... ... . 08 to 1'6 Muscle fluoresced a little more than one 128th of a grain of quinine to a litre ... ... ... ... ... ... ... ... ... ... =.0'8 Spleen fluoresced one 128th of a grain of quinine to a litre. . =0'8 In another patient , who died after a surgical operation , the same quantity of substance , treated in exactly the same way , gave[Apr . 12 , 88 Extract from per 100 litres Cartilage fluoresced a little less than one 128th of a grain of quinine to a litre ... ... ... ... ... ... ... =0'8 Nerves fluoresced a little less than one 128th of a grain of quinine to a litre ... ... ... ... ... ... ... ... . . =0'8 Liver fluoresced a little less than one 64th of a grain of quinine to a litre ... ... ... ... ... ... ... ... ... ... . = -1'6 Kidney fluoresced a little less than one 64th of a grain of quinine to a litre ... ... ... ... = 1'6 Lungs fluoresced one 128th of a grain of quinine to a litre. . =0'8 Muscle fluoresced between one 128th and one 64th of a grain of quinine to a litre - ... ... .=0'8 to 1'6 Spleen fluoresced a little less than one 128th of a grain of quinine to a litre ... ... ... . ; ... ... ... ... ... ... ... . . =08 Heart fluoresced one 128th of a grain of quinine to a litre. . =0'8 When a much larger quantity of each organ was taken ( whether from loss or destruction of substance in the process of preparation ) , no great increase of fluorescence was obtained . Thus , of the different parts of a man who died of apoplexy , six grains were taken and treated as in the previous cases . Extract from per 100 litres . Cartilage fluoresced one 128th to one 64th of a grain of quinine to a litre ... ... ... ... ... ... ... ... ... ... ... . =08 to 1'6 Nerves fluoresced one 64th of a grain of quinine to a litre. . 1'6 Liver fluoresced one 64th of a grain of quinine to a litre ... . = 1'6 Kidney fluoresced one 64th to one 32nd of a grain of quinine to a litre ... ... ... ... ... ... ... ... ... ... =1'6 to 3'1 Lungs fluoresced one 64th of a grain of quinine to a litre. . =1'6 Muscle fluoresced a little less than one 64th of a grain of quinine to a litre ... 6 ... ... ... ... ..= 16 Spleen fluoresced one 64th to one 32nd of a grain of quinine to a litre ... ... ... . . =16 to 31 Heart fluoresced one 32nd of a grain of quinine to a litre. . =3 1 Brain fluoresced one 64th to one 32nd of a grain of quinine to a litre ... ... ... ... ... . = 1-6 to 3-1 In a precisely similar way the different parts of the tissues of a woman who had taken small doses of quinine up to twenty-four hours of her death , were examined . The tissues were dried in a water-bath , and 0'6 grain of the dry substance was taken for examination . Extract from per 100 litres . Kidney fluoresced one 32nd to one 16th of a grain of quinine to a litre ... ... ... ... ... -- , ==3'1 to 6'3 I Nerves fluoresced a little more than one 64th of a grain of quinine to a litre ... .= ... ... ... ... ... ... ... = 1'6 Liver fluoresced one 64th of a grain of quinine to a litre ... . =1 ' 6 Muscle fluoresced one 64th of a grain of quinine to a litre. . =1'6 Spleen fluoresced a little less than one 32nd of a grain of quinine to a litre ... ... ... ... ... ... ... ... ... . =31 Lungs fluoresced one 128th to one 64th of a grain of quinine to a litre ... ... ... ... ... .=08 to 1-6 Fourthly . On the increase of fluorescent substance in the human lens after different quantities of sulphate of quinine had been taken at different periods before the operation for cataract ( for the means of making these experiments we are indebted td the great kindness of Mr. Bowman):The fluorescence of the human lens without cataract was about equal to one 64th of a grain of quinine in a litre of water ; grs. per 100 litres . That is , natural fluorescence about ... ... ... ... ... ... . . 1'6 Sulphate of quinine was given for many days previous to the extraction of a cataract . After the operation the fluorescence was found to be less than one 16th and more than one 32nd of a grain of quinine to a litre of water ... ... =c6'2 to 3'1 In four patients , aged respectively 75 , 60 , 60 , and 72:the lens removed 1 hour after 5 grains of quinine , fluorescence =1 6 , , 14 , , , , =1'6 , 2 , , =1-6 2 , , 2 , , =-21 to 1-6 Fifthly . On the rate of increase of fluorescent substance in the urine after quinine was taken , or on the rapidity of the passage of quinine , when taken by the stomach , into and out of the urine of man : A healthy man breakfasted at 8.30 A.M. ; at 12 he emptied the bladder , and took four grains of sulphate of quinine in solution . The fluorescence of the urine at different periods after the quinine was taken was examined by rendering it alkaline with caustic potash and shaking it up three times with its own bulk of ether . Half an ounce of urine was taken for each examination . Urine passed at gr. of quinine . water . 12 ( just before taking the quinine ) , fluorescence=ie --to -4 to 1 litre . 12.10 , fluorescence ... ... ... ... ..= , 12.20 , , ... ... ... .= to , , 12.30 = 4to4 , , 12.30 , , ... ... ... ... ... ... ... to 1 ... ... ... ... ... ... ... . to 2 ... ... ... ... ... ... = tol 4 , , ... ... ..o ... ... ... ... ... t , 8 , . 8 24 hours after quinine , fluorescence ... ... ... little less . 48 , ... ... ... . , little more . 72 , , , ... . about 1 ? , [ Apr. 12 , 90 The same man breakfasted at 8.30 A.M. ; at 12 took four grains of sulphate of quinine . Urine passed at gr. of quinine . water . 12 ( just before taking the quinine ) , fluorescence -= to to 1 litre . 12.10 , fluorescence ... ... ... ... ... ... ... . to ~~1 ~~~2 . ~~-20 , * Urine passed at . gr. of quinine . water . 12.30 , fluorescence below ... ... ... ... ... ... . . to 1 litre . 1 , ... ... ... ... ... ... . . I to i2 , , , ... ... ... ... ... ... . . ? to 1 , , 4 , , , ... ... ... ... ... ... . . to , , , ... ... ... ... ... ... . . to , , 24 , , , ... ... ... to 11 48 , ... ... ... ... ... ... . . I e , 72 , , , ... . . scarcely perceptible . The same boy breakfasted at 8.30 , passed urine at 12 noon , and immediately took four grains of sulphate of quinine . The fluorescence was observed in half an ounce of the urine passed at different periods after the quinine was taken . Urine passed at gr. of quinine . water . 12 ( just before taking the quinine ) , fluorescence 1 - , little more , to 1 litre . 12.15 , fluorescence ... ... ... ... ... ... ... y to 12.30 , , , ... ... ... ... ... ... ... . 1 1 , , , ... ... ... ... ... ... above 1 , , 2 , , ... ... ... ... ... ... above 1 , 3 , , , ... ... ... ... ... . . above I ( was at maximu ) , , 4 , , ... ... ... ... ... ... .above 1 8 , , , ... ... ... ... ... ... . . 1 24 , , ... ... ... 48 , ... ... ... ... ... ... ... . to 72 , , , ... ... ... ... ... ... ... not perceptible . Henlce in fifteen minutes quinine is detectable in the urine , and in three hours the maximum quantity is present in the urine . In eight hours it begins to decrease ; in forty-eight hours it is much decreased ; and in seventy-two hours it has entirely disappeared . CONCLUSIONS . Part I. From every texture of man and of some animals a fluorescent substance can be extracted , which is identical with the fluorescent substance that for some years has been known to exist in the lenses of man and animals . This fluorescent substance , when extracted , has a very close optical and chemical resemblance to quinine , and when mixed with quinine it cannot be separated from it ; we have therefore called it " animal quinoidine . " Part II . By quantitative determinations of the amount of fluorescent substances naturally existing in the textures , we were able to determine the rate and time of increase of fluorescent substance in the vascular and non-vas . cular textures of animals , and in the urine of man after quinine had been taken . By this means we have shown that in guineapigs , in fifteen minutes , the quinine has certainly passed into all the vascular , and most probably into the extra-vascular textures . In three hours the amount of quinine in the textures may be at the maximum ; and for six hours it does not much diminish . In twenty-four hours the quinine sinks very considerably , and in forty-eight hours it is scarcely perceptible anywhere . By similar experiments on cataracts in man , it appears that in two hours and a quarter traces of quinine may be found in the lens . After quinine has been taken , it begins to appear in the urine in from ten to twenty minutes ; in from two to three hours it has reached its maximum ; in from three or four , or at longest eight hours , it begins to decrease ; in twenty-four hours it has very much decreased ; in fortyeight hours its presence is still detectable ; but in seventy-two hours not a trace of it can be found . II . " On a Fluorescent Substance , resembling Quinine , in Animals ; and on the Rate of Passage of Quinine into the Vascular and Nonvascular Textures of the Body . " By H. BENCE JONES , M.D. , F.R.S. , and A.DUPR33 , Ph. D. , F.C.S. Received March 14,1866 . PART I. On a Fluorescent Substance , resembling Quinine , in Animals . The term fluorescence in the last few years has found a place in physiological works because different substances that occur in the body have been said to possess the property of fluorescence . Of these the solution of bileacids in concentrated sulphuric acid , the white of egg when kept for a H2 73 short time , and the urine sometimes , are the best-known fluorescing substances . But as long since as 1845 , Professor Briicke , in Miiller 's Archiv , ' stated that he had found in many and very frequently repeated experiments , that the lens absorbed the blue rays of light to a very great extent , and that the cornea and the aqueous humour did so to a less extent , but that the lens together with these other media absorbed these rays to the greatest degree . He used the eyes of oxen and of rabbits , and the lens of a pike 's eye , which last , when dried with care , preserved its transparency , and allowed the light to fall on a porcelain plate covered with tincture of guaiacum and bleach a portion of the green surface . Professor Stokes , in his well-known paper " On the Change of the Refrangibility of Light , " in the Philosophical Transactions for 1852 , says ( p. 512 ) , " It is found that the property of change of refrangibility in the incident light is extremely common . " " To make a list of sensitive substances would be useless work ; for it is very rare to meet with a white or light-coloured organic substance which is not more or less sensitive . " Among others he mentions horn , bone , ivory , white shells , leather , quills , white feathers , white bristles , the skin of the hand , and the nails . And in his conclusion ( p. 557 ) , he says , " The phenomenon of change of refrangibility proves to be extremely common , especially in the case of organic substances , such as those ordinarily met with , in which it is almost always manifested to a greater or less degree . " When speaking of the fluorescence of sulphate of quinine , he says ( p. 541 ) , " When quinine was dissolved in dilute hydrochloric acid , the blue colour was not exhibited , not even when the fluid was held in the sunlight and examined by superficial projection . " In 1855 Helmholtz published a paper in Poggendorff 's 'Annalen , ' vol.xciv . p. 205 , in which he says that , as far as quinine paper showed that the spectrum extended , so far the eye could perceive light * . He then proposes this question , Does the retina see the rays beyond the violet directly as it sees other colours of the spectrum , or does it fluoresce under the influence of these rays ? and is the blue colour of the rays beyond the violet light of less refrangibility which shows itself in the retina only under the influence of the violet rays ? To determine this question , he says , I examined for fluorescence the retina of the eye of a man who had been dead for eighteen hours . The first experiment showed that it was very feebly fluorescent . The retina was less fluorescent than paper , linen , and ivory , but more than porcelain . The colour of the light dispersed through the retina is greenish white , very different from that which the direct perception of these rays usually gives . In 1858 , in the Comptes Rendns des Seances de la Societe de Biologie pendant le mois de Novembre 1858 , pp. 166 & 167 , there is a short notice headed " Analyse et conclusions d'un travail sir la fluorescence des milieux de l'ceil , par M. Jules Regnauld . " He used sunlight , and found in man and the mammifera that the cornea fluoresced in a very slight degree . In the sheep , dog , cat , and rabbit , the crystalline lens possessed in the highest degree fluorescent properties . In these animals , and also in many birds , the central part of the lens ( endophaine of MM . Valenciennes and Fremy ) , preserved by desiccation at a low temperature , retained this property . The central portion of the crystalline of many aquatic vertebrata and mollusca ( phaconine of MM . Valenciennes and Fremy ) is almost entirely without fluorescence . The hyaloid body possesses only a very feeble fluorescence , due to the hyaline membranes ; for the vitreous humour itself is not fluorescent . The retina , as M. Helmholtz discovered , possesses a certain fluorescence which is not at all comparable in intensity to that of the crystalline lens of mammifera . Finally , M. Regnauld concludes that , if we must attribute the accidents caused by feebly luminous radiations of the electric light to the phenomena of fluorescence , it is above all in the energetic action on the crystalline that it is natural to look for an explanation . The impression which the cornea undergoes must nevertheless not be neglected . In 1859 , in the 'Archiv fur Ophthalmologie , ' vol. v. part 11 . p. 205 , there is a paper by J. Setschenow of Moscow , " On the Fluorescence of the Transparent Media of the Eyes of Man and some other Animals . " He undertook the examination at Professor Helmholtz 's request , because it was possible that the phenomena of fluorescence observed by Helmholtz might have been modified by a post-mortem change in the eye . He experimented on the eyes of oxen and rabbits . The fresh retina showed the same phenomena as the dead human retina . It diffused a greenish-white light , which , examined by a prism , gives a spectrum in which the red is wanting . The vitreous humour in a thin glass vessel showed only traces of fluorescence . The lens , on the contrary , fluoresced very strongly : the colour of the dispersed light is white-blue , exactly like quinine ; only the quinine was a little stronger . Examined by a prism , the dispersed light gave a spectrum in which the red was wanting , and in which the blue tone predominated . The fluorescence begins , as in quinine solutions , between G and H , and is strongest at the outer edge of the violet rays , and extends into the ultraviolet to the same distance in the case of the lens as in the case of the quinine solution . 75 1866 . ] When the cornea was cut out , it fluoresced much feebler than the lens ; the aqueous humour did not fluoresce at all . The appearances in the three last media , he says , can be shown with the greatest ease , even in the eye of a living man . When the eye is brought into the focus of the ultra-violet rays , immediately the cornea and the lens begin to glimmer with a white-blue light . The cornea in the living eye is much more strongly fluorescent than when dissected out , probably from the loss of transparency consequent on contraction of the texture and from evaporation . The question how and why our eyes perceive the ultra-violet spectrum is still undetermined . The fluorescence of the lens would be rather a hindrance than a help ; only the general sensibility to the light which the ultra-violet rays produce in our eyes can be explained by the fluorescence of the media lying before the retina . In 1862 , ' Zeitschrift ffir Rationelle Medicin , ' 3rd series , vol. xiii . p. 270 , Pfluger , by mixing fresh ox-gall with concentrated sulphuric acid , saw a clear dichrotic solution form . It had a deep red colour by transmitted light , and a beautiful green colour by reflected light . This was seen very beautifully when dried bile was put into sulphuric acid ; and then the dichroism increased by standing . It is desirable to separate the cholesterin and the bile-fats . The green fluorescence appeared when only blue or green light fell on the sulphuric-acid solution of the bile . On the contrary , it did not appear when the light was only yellow or red . The sulphuric-acid solution of the bile absorbed all the rays of the spectrum except the yellow and the red . In the ' Journal fiirPrakt . Chem. ' vol. xcii . p. 167 , Schonbein has the following remarks on the formation of a fluorescing substance in the putrefaction of human urine : If urine is left to stand in the air until it becomes covered on the surface with a thick layer of fungus , the alkaline fluid that filters from it shows a very strong fluorescence of a greenish colour . Small quantities of the stronger organic or inorganic acids take away this fluorescence , which , however , by alkalies can be again reproduced . This substance has a reaction like esculine , and , like this , is the opposite to quinine , the fluorescence of which is increased by those acids . The hydrobromic , hydriodic , and hydrochloric acids lessen the fluorescence of the solution of quinine almost to entire removal . Schonbein also remarked that fresh urine had a feeble fluorescence , and also that a weak solution of albumen , by standing long in the air , became fluorescent to a considerable degree . This was the state of our knowledge of fluorescence in animals when , having traced the rate of passage of chloride of lithium and other mineral substances into and out of the textures by means of the spectrum analysis , we endeavoured to find some method of determining the rate at which organic substances passed into and out of the same structures . 76 [ Apr. 12 , Among all the delicate tests for different organic substances , the fluorescence of sulphate of quinine appeared likely to afford good results ; for the following experiments on the delicacy of this test for sulphate of quinine show that this method of tracing sulphate of quinine into and out of the body , though inferior to the spectrum determinations of lithium , was superior in delicacy to the spectrum determinations of many other substances . On the Delicacy of the Fluorescent Test of Sulphate of Quinine when a Ruhmkorf coil was used as the source of light . One grain of sulphate of quinine was dissolved in five ounces of acidified water , and this was again and again diluted until one grain of quinine-salt was present in 1,800,000 parts of water . This , when examined in a quartz cell by the induction-spark , showed blue fluorescence distinctly in twenty grains of solution . Another grain , dissolved in a litre and diluted until one grain of salt was present in 1,440,000 parts of water , when acidified , also showed the fluorescence distinctly in twenty grains of solution . The same quantity , dissolved in one litre of water , was diluted to 512 litres . This was equal to one part in 7,200,000 parts of water ; as the fluorescence could be seen in twenty grains of this solution , 36 of a grain of sulphate of quinine gives the fluorescence . In another experiment , 250 of sulphate of quinine , in fifty minims of water acidified , showed the fluorescence strongly , and even 6o , of a grain of sulphate of quinine in fifty minims of water showed the fluorescence feebly . As the fluorescence could be seen in twenty grains of this solution , 20-00 of a grain of sulphate of quinine gives the fluorescence . In the last two sets of experiments the light of a bright induction-spark was concentrated by a small quartz lens . One grain of disulphate of quinine , dissolved in 256 litres of water acidulated with one-eighth of sulphuric acid ( 1 to 8 ) , shows fluorescence feebly in a quartz cell containing twelve grains of the solution . Ience 310grain gives the fluorescence feebly . If one grain of disulphate of quinine is dissolved in a thousand litres , or one part of quinine to 15,440,000 of water , the fluorescence is still perceptible in one ounce of the solution . On the Existence of an extractable Fluorescent Substance in Animals and Man . Immediately on trying to apply this reaction to test the different textures of guineapigs , after and before they had taken quinine , we found that in health no part of any of the tissues of the guineapig was free from blue fluorescence . It became desirable , therefore , to separate the fluorescence produced by some fluorescing substance normally present in the tissues from that produced after quinine was given . After very many attempts to extract these substances separately from the tissues , and many more to separate them when they were conjointly extracted , all of which proved unsuccessful , we resorted to the plan of determining the amount of natural fluorescence by comparing it with standard solutions of sulphate of quinine ; and by the same means we measured the increase that occurred in the amount of fluorescence from the same organs after quinine had been taken . The following plan was adopted for the extraction of the fluorescent substance from the textures , both before and after quinine was taken . The part to be examined was treated on a water-bath with very dilute sulphuric acid , either directly or after previous drying in a water-oven . This extraction was repeated again and again . The acid extracts were mixed , filtered after cooling , neutralized with caustic soda , and repeatedly shaken up with their own bulk of ether . The residue left after evaporation of the ether was taken up by dilute sulphuric acid , filtered , and tested for the amount of fluorescence after having been made up to a certain bulk , generally twenty-five minims . When a large quantity of material , as two or three pounds of liver , was employed , the acid extract was a second time neutralized and treated with ether ; the residue from the second ethereal solution was then taken up with dilute sulphuric acid and tested . In very dilute solutions the fluorescence of the animal substance cannot be distinguished from that produced by quinine ; if the solution is more concentrated , the fluorescence of the animal substance is confined much more to the surface , the fluorescence in a solution of quinine passing much further into the liquid ; and in still more concentrated solutions , the colour of the light given out is of a decidedly greenish hue . The fluorescence also of the animal substance begins to appear somewhat nearer to the red end of the spectrum than is the case with quinine ; but both extend to the same distance beyond the violet end . From two to three pounds of liver , only about fifty minims'of a solution was obtained showing a fluorescence equal to that produced by two or three grains of quinine to the litre of water ; and when slightly acidified , the-following reactions were obtained with the solution . It gives a precipitate with solution of iodine , with a solution of iodide of mercury in iodide of potassium , and also with phosphomolybdic acid , bichloride of platinum , and terchloride of gold : this last precipitate is soluble in alcohol , like that produced in solutions of quinine . A weak solution of quinine interposed in a quartz cell before the solution of the natural fluorescing substance , did not stop the fluorescence of this latter substance entirely ; but when the solution of animal substance was placed before the solution of quinine , no fluorescence whatever could be perceived in the quinine . ]Ether is unable to extract the animal substance from an acid solution ; the acid solution may be shaken up several times with ether ; but the ethereal solution on evaporation yields a residue which , when taken up by dilute sulphuric acid , gives no blue fluorescence whatever . The fluorescence of this animal substance is much less strong in hydrochloric acid solutions by the light of the coil-spark , and it is almost destroyed 78 by alkalies . The substance does not lose its fluorescence when treated with dilute sulphuric acid on a water-bath , nor even on the addition of a dilute solution of permanganate of potash . In an alkaline solution with permanganate of potash it is immediately destroyed . Quinine behaves in a precisely similar way . Parts of the brain , kidney , liver , and heart , and the crystalline lens of a human subject dead for many hours , were boiled with dilute sulphuric acid , neutralized with carbonate of soda , and extracted with ether . The ethereal residue , dissolved in dilute sulphuric acid , was examined by the spark of the Ruhmkorf coil for fluorescence . From every part the extract fluoresced distinctly but very feebly . The fluorescence closely resembled that caused by a very weak solution of quinine . The lenses from sheep 's , bullocks ' , pikes ' , eagles ' eyes , gave a distinctly fluorescent substance , and the extract from the sheep 's liver fluoresced very strongly . Cod-liver oil also fluoresced very distinctly . The so-called pills of cod-liver oil gave no fluorescence . The fluorescent substance could be extracted by treating the finely divided substance with alcohol , and the residue of the alcohol solution by ether , and finally dissolving the ethereal residue in water acidulated with sulphuric acid . It follows from these experiments that there exists in the body of man and animals , fishes , and birds a substance which can be extracted from any of the tissues by the same process as quinine when present can be extracted . This substance has the same reactions with chemical agents as quinine has , and the action of light upon this substance is almost , although not altogether , identical with its action on quinine . This substance is visible in the lens of the human eye during life . It is , from its mode of separation and reactions , an alkaloid bearing a close resemblance in its properties to quinine . For the present we shall call this animal quinoidine . It is the cause of the blue fluorescence of weak acid extracts from any of the tissues of the body of men and animals . When concentrated , the fluorescent substance is bluish green . On the Fluorescent Substance produced by treating Bile with strong Sulphuric Acid . We were unable to insulate and extract the substance which causes the green fluorescence in bile when it is treated with strong sulphuric acid ; nor could we separate that which forms in white of egg when a solution in water is exposed to the air . The bile dissolved in strong sulphuric acid was transparent by transmitted light , and appeared as a brownish-yellow solution ; by reflected light , even with the ordinary gaslight , it showed a strong green fluorescence , in much larger quantity than , and entirely different in appearance from , the blue fluorescent substance of the liver . Thus it was destroyed by diluting the acid with water , but returned on the addition of a larger quantity of strong sulphuric acid . The solution of egg-albumen , exposed to the air , gradually after some days showed a strong green fluorescence , which , like esculine , disappeared on the addition of an acid , but was not destroyed by alkalies . The fluorescence gradually disappeared when the albumen began to putrefy . PART II . On the Increase of Fluorescence in the Textures of Animals and Mcan after Quinine had been taken . Having proved that in all the different textures of an animal a natural alkaloid fluorescent substance was present when no quinine had been taken , and as no means could be found for separating the natural fluorescent substance from the quinine when it passed into the textures , it became necessary to make our analyses quantitative instead of qualitative . For this purpose it was necessary to determine , by means of standard solutions of quinine , what was the greatest amount of naturally fluorescent substance that usually occurred and , could be extracted from the tissues . Deducting this from the amount of fluorescence that could be extracted after quinine was given , we were enabled to measure the rapidity of passage of the quinine into or out of the tissues , the animals being destroyed at different periods after different quantities of sulphate of quinine had been taken . So also by determining the amount of natural fluorescent substance in the textures , lenses , and urine of man before quinine was taken , and deducting this from the amount obtained after quinine was taken , we were enabled to show that quinine does pass into the textures and lenses , and how quickly it appeared in the urine and reached its maximum and began to disappear and entirely vanished . First . Examinations of different textures of guineapigs when no quinine was taken , and comparison of the amount of natural fluorescent substance with standard solutions of sulphate of quinine . The amount of the different parts examined was as nearly as possible always the same : 1 . A guineapig that had taken no quinine was killed ; the extract of the brain and nerves only was measured . The fluorescence of the nerves was very feeble , and about equal to one-twentieth of a grain of sulphate of quinine in a litre of water . The extract of the brain was exceedingly feeble , and it was less than one-thirtieth of a grain of sulphate of quinine in a litre of water . 2 . In another guineapig the lenses and the nerves were dried , and boiled three times with dilute sulphuric acid . The acid solution was rendered alkaline by caustic potass , and it was then shaken up with ether three times . The ethereal solution was evaporated , and the residue dissolved in dilute sulphuric acid . The acid solution was made up to twenty-five minims . The solutions of the lenses and of the nerves showed some fluorescence . These acid solutions were now again rendered alkaline and were shaken up with ether , and the ethereal solution was evaporated and the residue I_ _ _I _ issolved in acetic acid , and the excess of the acid evaporated in a waterbath ; the residue was dissolved in a little water , and the solutions were divided into two parts . The half of the solution from the lenses and nerves , when tested with a solution of iodine and a solution of iodide of mercury , remained perfectly clear . The bile , brain , and liver , tested in the same way , gave no precipitates with these reagents , although they also gave slight fluorescence . The different parts of this pig were compared with the corresponding parts of two other pigs , one of which took sixteen grains of sulphate of quinine in nine doses in four days , and the other twenty-six grains in fourteen doses in six days . 3 . Another guineapig had the different organs treated in exactly the same way ; the liver , lenses , kidneys , urine , blood , brain , nerves , and muscle gave a fluorescence which varied from about one-twentieth to onethirty-second part of a grain of quinine in a litre of water . This pig was bought at the same time and place , and fed in the same way as two other pigs ( 18 and 23 ) , that were given six grains of sulphate of quinine in three doses with twenty minutes ' interval . One pig was killed between five and six hours after the quinine , and the other in twenty-four hours . 4 . Another pig was also treated in the same way , for comparison with three other pigs which took five grains of quinine , and were killed four hours , eight hours , and thirty-two hours afterwards . The lenses , humours , brain , blood , nerves , and muscle gave a fluorescence varying from onetwenty-fifth to one-fiftieth of a grain of quinine in a litre of water . 5 . Another pig had taken no quinine . The brain gave a fluorescence equal to one-thirtieth of a grain of quinine , and the nerves fluoresced equal to one-twentieth of a grain of quinine . 6 . Another guineapig had equal quantities of the liver , bile , kidney , urine , brain , lenses , humours , nerves , blood , and muscle treated in the same.way . The fluorescence obtained from the liver was from one-thirtysecond to one-sixteenth part of a grain of quinine . The fluorescence of all other parts was less than one-thirty-second part of a grain of quinine . The fluorescence of the humours was least of all . 7 . Another guineapig was given no quinine . Equal quantities of dry liver , blood , bile , kidney , brain , nerves , lenses , muscle , and humours were taken . Of the bile and humours , which were taken entire , rather less than half a grain , of the other parts half a grain was used ; the liver fluoresced equal to one-sixteenth of a grain of quinine . The bile , blood , kidney , brain , nerves , lens , and muscle showed somewhat less than one-sixty-fourth part of a grain to a litre ; the humours of the eye rather more than one-sixtyfourth part . 8 . Another pig , bought at the same time and place as 17 , was given no quinine ; and the fluorescence of every part was less than one-sixtyfourth of a grain of quinine in a litre of water . The fluorescence of each solution was rendered still less by the addition of common salt . 81 1866 . ] Secondly . On the increase of fluorescence that was observed when different quantities of sulphate of quinine were given to animals at different periods before they were killed:9 . A guineapig was given sixteen grains of sulphate of quinine , in nine doses , in the course of four days . It was found dead more than twelve hours after the last dose . Its fluorescence was compared with pig 2 , which had taken no quinine ; the lenses and the nerves , treated the same way , showed much more fluorescence in the pig that had taken quinine than in the other which had had no quinine . The solutions of the lenses and the nerves also gave a distinct precipitate , which was least in the solution of the lenses with solutions of iodine and of iodide of mercury ; whilst the solutions of the lenses and the nerves of the pig that had taken no quinine remained clear . The bile and the brain fluoresced brightly . The solution of the liver , when diluted even to one hundred minims , fluoresced distinctly in daylight , and very strongly in the light of the spark . The brain-solution gave a distinct precipitate with iodine and iodide of mercury . The bile gave a very faint turbidity . The liver gave an abundant precipitate , and moreover gave Herapath 's test for quinine very distinctly . 10 . Another pig took twenty-six grains of quinine , in fourteen doses , during six days . It was killed nineteen hours after the last dose , being apparently partially paralyzed . The solutions of the different organs were prepared in the same way as 9 and 2 , and they were examined at the same time . The lenses showed the fluorescence very strongly when a cone of sunlight was thrown into them with a quartz lens . The humours showed no fluorescence at all in this manner . The solutions of the bile , brain , urine , nerves , lenses , spinal marrow , liver , gave more or less distinct fluorescence . The solution of the brain gave no precipitate with iodine or iodide of mercury ; nor did the bile give a precipitate , but the liver gave a slight precipitate with both reagents . Having thus satisfied ourselves that quinine does pass into the vascular and non-vascular tissues , we proceeded to determine how quickly four , five , or six grains of sulphate of quinine given to guineapigs could be detected in the different textures of their bodies . 11 . A guineapig was given four grains of sulphate of quinine , and it was killed in one quarter of an hour ; all the extracts from the different parts of the body were mixed with one-eighth of their bulk of dilute sulphuric acid , and were made up to twenty-five minims . The amount of fluorescence was compared with the fluorescence obtained in pig 6 , and with standard solutions of sulphate of quinine with one-eighth of dilute sulphuric acid , containing one grain , three-quarters , half , one-eighth , one-sixteenth , and one-thirty-second of a grain of sulphate of quinine . The solutions of the extracts of pigs 19 , 22 , 25 , and 26 , which had taken four grains of sulphate of quinine and were killed six hours , twenty-four hours , forty-eight hours , and seventy-two hours after the quinine was taken , were examined at the same time . [ Apr. 12 , The urine and the blood gave a fluorescence equal to half a grain of quinine to a litre of water ; the extract of the kidney and the liver gave a fluorescence equal to three-fourths of a grain of quinine ; the extract of the muscle gave a fluorescence between half a grain and one-fourth of a grain . The extract of the bile and the brain gave a fluorescence nearly equal to one-eighth of a grain of quinine to a litre . The nerves gave rather more fluorescence than one-sixteenth of a grain of quinine , and the lenses gave between one-sixteenth and one-thirty-second of a grain . Comparing these numbers with pig 6 , in which the fluorescence of the liver was greatest , amounting to from one-thirty-second to one-sixteenth of a grain of quinine to a litre of water , whilst in all other parts , urine , blood , kidney , muscle , bile , brain , nerves , and lenses , the natural fluorescence was less than one-thirty-second of a grain , it is evident that in a quarter of an hour sulphate of quinine passes into all the vascular and non-vascular structures of the body . 12 . Another guineapig was given four grains of sulphate of quinine , and it was killed in half an hour ; the nerves and brain were compared with pig 1 , which had taken no quinine . The extract of the liver and kidneys gave a fluorescence equal to two-fifths of a grain of sulphate of quinine in a litre ; the blood , the bile , and the muscle gave a fluorescence equal to onefifth ; the urine gave a fluorescence between one-fifth and one-tenth ; the brain between one-tenth and one-twentieth ; the humours of the eye fluoresced feebly , but a little more than the lenses , about one-twentieth ; the lenses and the nerves less than one-twentieth of a grain of quinine . 13 . Another guineapig took four grains of sulphate of quinine , and was killed one hour afterwards . The blood , the kidney , and the urine gave a fluorescence equal to , or rather more than , one-fifth of a grain of quinine to a litre ; the liver fluoresced equal to between one-fifth and two-fifths of a grain of quinine ; the bile and the muscles gave a fluorescence equal to one-twentieth of a grain of quinine ; the brain fluoresced between onetwentieth and one-thirtieth ; the humours fluoresced rather more than the lenses ; and the nerves gave the slightest fluorescence . 14 . Another guineapig was given four grains of sulphate of quinine ; after three hours it was killed . It had been strongly affected , and the brain was much congested . The liver , kidney , blood , urine , bile , brain , and muscle gave very strong fluorescence , equal to between one and two grains of quinine in a litre of water ; the nerves gave a fluorescence equal to one-sixteenth of a grain of quinine ; the humours gave a fluorescence between one-sixteenth and one-thirty-second part of a grain ; the lenses less than one-thirty-second part of a grain of quinine to a litre of water . 15 . Another guineapig was given four grains of sulphate of quinine ; after three hours it was killed . Of every part half of the dry substance was taken , except the aqueous humour , bile , and urine , of which the whole was taken ; but when dry each of these was less than half a grain . Half the muscle gave a fluorescence equal nearly to one-sixteenth of a grain of quinine in a litre ; half the brain fluoresced a little more than one-thirty-second ; half the kidney one-eighth to one-fourth of a grain ; all the urine oneeighth ; half the blood fluoresced one-sixty-fourth to one-thirty-second ; half the liver a little more than one-sixteenth ; all the bile a little less than one-fourth ; half the lenses a little less than one-sixty-fourth ; all the humours a little more than one-sixteenth ; half the nerves one-sixtyfourth to one-thirty-second of a grain of quinine to a litre of water . 16 . Another guineapig was killed four hours after five grains of sulphate of quinine , in two doses , with half an hour 's interval . The fluorescence of the different extracts of the tissues was compared with that of pig 4 , that had taken no quinine , and with pigs 21 and 24 , that were killed after taking a dose of five grains eight and thirty-two hours previously . The liver , the kidney , the brain , and the muscle gave a fluorescence about equal to one grain of quinine in a litre of water ; the blood rather less ; the nerves rather more than the blood ; the lenses and the humours less than the blood . 17 . Another pig was killed four hours and a half after four grains of quinine . The whole of each organ was taken ; the muscle gave a fluorescence equalling from one-half to one grain of quinine to a litre of water ; the brain one-sixteenth to one-eighth of a grain ; the kidney fluoresced nearly equal to one grain ; the urine rather more than one grain ; the blood oneeighth to one-fourth ; the liver nearly one ; the bile a little more than oneeighth ; the lenses , humours , and nerves fluoresced less than one-sixtyfourth of a grain of quinine to a litre of water . This pig was compared with one which was given no quinine . 18 . Another pig was killed five hours and a half after six grains of sulphate of quinine , given in three doses , with twenty minutes ' interval . It was very much affected . The extract of its tissues was compared with pig 3 , which had taken no quinine ; the liver , kidney , and muscle fluoresced very strongly ; the brain fluoresced strongly ; the blood fluoresced between one-fifth and two-fifths of a grain to a litre of water ; the nerves and the lenses fluoresced much less . 19 . Another pig was killed six hours after four grains of sulphate of quinine . The liver and kidney fluoresced equal to from one-half to onefourth of a grain of sulphate of quinine to alitre of water ; the urine from one-eighth to one-quarter ; the blood fluoresced about one-eighth , the muscle a little more ; the brain and the humours of the eye about one-sixteenth of a grain of quinine ; the lenses between one-sixteenth and onethirty-second , and the nerves rather less than one-thirty-second part of a grain of quinine ; the fluorescence was compared with pig 6 , that had taken no quinine . 20 . Another pig was killed six hours after four grains of sulphate of quinine . The liver gave a fluorescence equal to between one and two grains of sulphate of quinine ; the kidney and the urine gave a fluorescence equal to one grain of quinine ; the blood fluoresced between one grain and half a grain ; the bile equalled three-quarters of a grain ; the muscles and the brain one-quarter of a grain ; the nerves one-sixteenth of a grain ; the [ Apr. 12 , 84 humours rather more than one-thirty-second of a grain ; and the lenses between one-thirty-second and one-sixty-fourth of a grain to a litre of water . 21 . Another guineapig was killed in eight hours after taking five grains of sulphate of quinine , in two doses , with half an hour 's interval . The extract of its tissues was compared with pig 8 , which had taken no quinine , and with pig 16 and pig 24 , which were killed four hours and thirty-two hours after taking five grains of quinine ; the fluorescence of the liver was very strong ; the muscles , the brain , and the kidneys showed the fluorescence very distinctly ; the fluorescence of the urine equalled from two-fifths to three-fifths of a grain of quinine ; the bile was not more than one-twentieth of a grain of quinine ; the blood fluoresced more distinctly ; the lenses and the humours not so much , and the nerves least of all . This pig was with young when killed , and the fluorescence of the foetus was distinct ; the fluorescence of the liquor amnii was less than that of the foetus . 22 . Another pig was killed in twenty-four hours after taking four grains of sulphate of quinine . The fluorescence of its textures was compared with pig 6 , that had taken no quinine ; the fluorescence of the liver and kidney was equal to half a grain of quinine ; the blood and bile fluoresced equal to one-eighth of a grain ; the urine between one-eighth and one-sixteenth ; the muscle the same ; the brain and the humours rather less than one-sixteenth of a grain ; the lenses and the nerves about one-thirty-second of a grain of quinine to a litre of water . 23 . Another pig was killed twenty-four hours after taking six grains of quinine , in three doses , with 20 minutes ' interval . The fluorescence was compared with pig 3 , which had taken no quinine ; the liver showed the mostffluorescence ; the muscles , the kidney , and the brain were next ; the nerves and blood equalled about one-tenth of a grain of quinine , and the lenses fluoresced least of all . 24 . Another pig was killed thirty-two hours after taking five grains of sulphate of quinine . The fluorescence was compared with pig 4 , which had taken no quinine ; the liver fluoresced scarcely more than that of the pig that had taken no quinine , about one-twenty-fifth of a grain to a litre of water ; the kidney fluoresced a little more than that of the pig without quinine ; the fluorescence of the urine was scarcely perceptible , less than one-fiftieth of a grain of quinine ; the muscles a little less than the pig without quinine ; the blood , the nerves , the brain fluoresced very slightly ; the lens and the humours more than any other part . 25 . Another pig was killed forty-eight hours after four grains of sulphate of quinine . The fluorescence was compared with pig 6 , which had taken no quinine ; the extract of the liver and of the blood had a fluorescence equal to one-sixteenth of a grain of quinine in a litre of water ; the bile , the kidney , the urine , the brain , the lenses , the humours , the nerves , and the muscles had each a fluorescence less than one-thirty-second part of a grain of quinine . 1866 . ] 85 Another pig was killed seventy-two hours after four grains of sulphate of quinine . The fluorescence was compared also with pig 6 , which had taken no quinine ; the extract of the liver and of the brain had a fluorescence equal to one-sixteenth of a grain of sulphate of quinine ; the lenses had a fluorescence equal to one-thirty-second part of a grain ; the bile , kidney , urine , the nerves , blood , and muscle had a fluorescence less than onethirty-second part of a grain ; and the humours fluoresced much less than one-thirty-second part of a grain of sulphate of quinine in a litre of water . Fluorescence without quinine , measured by the number of grains of quinine in 100 litres of water ( 176 pints ) . Pig I. Pig 4 . Pig 5 . Pig 6 . Pig 7 . Pig 8 . Liver ... ... ... ... ... . 6 to3 less 6'2 less 1'6 Lenses ... ... ... ... less 3 , , 16 , , 16 Kidney ... ... ... ... . , 3 , , 1-6 , , 16 Urine ... ... ... . , , 3 , , 16 , ,16 Bile ... ... ... . , , 3 , , 16 , , 6 Blood. . 4 to 2 ... 3 , , 16 , , 16 Brain. . less 34 to 2 3 , , 3 , , 6 , , 16 Nerves. . 54 to 2 5 , 3 , , 16 16 Muscles ... . 4 to 2 ... . 3 , , 16 , , 16 Humours ... . 4 to 2 ... . least more l'6 , , 16 Fluorescence after quinine . Pig . 11 . Pig 12 . 'Pig 13 . Pig 14 . Pig 15 . Pigl . l Pig 17 . 15 min. 30 mmin . 1 hour . 3 hours . 3 hours . 4 hrs.t 4hours . Liver. . 75 40 20 to 40 100 to 200 6-2 100 100 -Lenses . 6 to 3 5. . 3 1-6. . 16 Kidney . 75 40 20 100 to 200 12to25 100 100 Urine. . 50 20 to 10 20 100 to 200 12. . 100 Bile ... . 12 20 5 100 to 200 25. . 12-5 Blood. . 50 20 20 100 to 200 1-6 12 to 25 Brain. . 12 10to3 5to3 100to 200 3 100 6 to 12 Nerves . 65 least 6 1-6 to 3. . 1-6 Muscles 50 to 25 20 5 100 to 200 6'2 100 50 to 100 Humours. . 5. . 6 to 3 6'2. . 1-6 Pig 18 . Pig 19 . Pig 21 . Pig 22 , Pig 23 . Pig 24 . pig 25 . Pig 26 . 5-4 hours . 6 hours . 6 hours . 8 hours . 24 hrs . 32 hrs . 48 hrs . 72 hrs . Liver ... . 50 to 25 100 to 200. . 50 466 Lenses ... 6to3 3 to. . 3. . 33 Kidney ... 50 to 25 100. . 50. . 33 Urine ... . 25 to 12 100 4 to 6 12 to 6233 Bile ... ... . . 75 5 12. . 33 Blood. . 20 to40 12 100 to50. . 12. . 63 Brain 6 25 6 ... . 3 rsv ; 33 ... 3 6. . 3. . 33 Muscles. . 12 25. . 12 to. . 33 Hum ours. . 6 3. . 6. . 3 least [ Apr. 12 , 86 From these experiments it is seen that the fluorescent substance which exists naturally in the tissues , at the very highest reaches to 6 grains in 100 litres of water , and usually is between 4 and 1 grains of quinine dissolved in this quantity of water . When quinine has been taken , even in a quarter of an hour the fluorescence may become equal to 75 grains of quinine in 100 litres of water . It is found to be in greatest quantity in the liver and the kidney , and somewhat less in the blood , urine , and muscles ; still less in the brain , nerves , and bile ; and the increase is slightly perceptible even in the lenses . In three hours the maximum effect of the quinine may be reached , the fluorescence being then from 100 to 200 grains of quinine in 100 litres of water . This amount was found in the liver , kidney , urine , bile , blood , brain , and muscles . The increase was much less perceptible in the nerves and in the aqueous humour , and was least in the lenses . In six hours the amount of fluorescence was rather less than in three hours ; in twenty-four hours it was considerably less than half as much as in three hours ; in forty-eight hours there was but little more fluorescent substance than naturally exists in the textures , except in the liver and the blood ; and in seventy-two hours there was no increase except in the liver . Hence , in guineapigs , in fifteen minutes the quinine has passed to all the vascular and probably to the extravascular textures . In three hours the amount of quinine in the textures may be at the maximum , and for six hours it remains in excess ; in twenty-four hours the quinine is much diminished , and in forty-eight hours it is scarcely perceptible anywhere . In order , if possible , to obtain very decisive proof that quinine passed into the non-vascular texture of the lens , we gave two pigs three grains of sulphate of quinine , and half an hour afterwards three grains more ; the animals were killed five hours after the first dose . One lens of each pig was put into glycerine , to be compared with the lenses of two other pigs bought at the same time and place , to which no quinine was given . In the electric light there was no apparent difference , either in the colour or in the brightness of the fluorescence , between the pigs that had taken quinine and those that had taken none . Examined by the spark of the coil , the fluorescence of all four lenses was less than one-sixty-fourth of a grain of quinine in a litre of water ; and scarcely any difference was perceptible , though the fluorescence of the lenses of the pigs that had taken quinine was slightly the strongest . In all , the fluorescence was rendered less strong by the addition of a strong solution of common salt to the solution . Two pigs were both given fifteen grains of sulphate of quinine in five doses of three grains each , with the interval of one hour between each dose . They were killed one hour after the last dose , being , however , almost dead from the effects of the quinine . One lens of each animal was examined in the usual way . The fluorescence in both was equal to one-thirty-second of a grain of quinine in a litre of water , or three grains per 100 litres .
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On the Bursa Fabricii
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102
1,866
15
Proceedings of the Royal Society of London
John Davy
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0023
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proceedings
1,860
1,850
1,800
9
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http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112593
10.1098/rspl.1866.0023
http://www.jstor.org/stable/112593
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Biology 2
58.503135
Biology 1
14.885525
Biology
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II . " On the Bursa Fabricii . " By JOHN DAVY , M.D. , F.R.S. , &c. Received March 24 , 1866 . In this paper I have the honour to submit to the Society some observations which I have made on the Bursa Fabricii-an organ respecting the function of which so little has yet been determined with any certainty , some physiologists regarding it , after the manner of the author who first described it , as a receptaculum seminis , others as the analogue of Cowper 's glands , others as that of the prostate ; and one as that of the urinary bladder of fishes . For the sake of ' order and to save some repetition , before entering into particulars it may not be amiss to state briefly that this peculiar organ , in every instance it is met with , is found to lie low in the cavity of the pelvis , behind the intestine , either directly in the median line , or a little on one side of it ; that it is covered anteriorly by the reflected peritoneum ; is composed mainly of two coats , one an outer muscular , the other an inner mucous , the latter in the instances of most development abounding in follicles ; that it communicates with the cloaca by an opening , in the female , close to the entrance of the oviduct , in the male between and a little inferior to that of each vas deferens , in both inferior to the termination of the ureters* ; and that it has over its orifice , when most perfect , a slight valvular fold , affording some , but not perfect , security against the entrance into its cavity of fsecal matter whilst passing in the act of expulsion . What is remarkable in this organ , giving rise to much of the obscurity adverted to , is the different aspects which it exhibits in the same animal according to age , and the differences as to form and proportional size and degree of persistence which it presents in different species . The number of birds in which I have sought for the organ , and have examined it when found , has been considerable , at least thirty different species , all of them , with the exception of the skylark , belonging to or frequenters of the Lake district . I may further briefly premise that , when the microscope has been used , the power employed has been that of -th inch focal distance , and that , when spermatozoa have been sought for , a drop of a solution of common salt of the sp. gr. 1038 , has been added to the fluid to be examined . In the descriptive part which follows , I propose to confine myself to the more striking examples illustrative of the peculiarities adverted to and likely to aid in accounting for them , passing over the several species , or very briefly noticing them , when displaying n marked difference . I. Common F owl ( Gallus domesticus).-I begin with this bird , as I have had the best opportunity of examining it at different ages . 1 . Of a chicken four days old , the bursa was about the size of a small pea ; it communicated with the cloaca , and was empty . 2 . Of another chicken , seventeen days old , found dead on the 10th of March from cold , the bursa measured *3 by '2 inch ; it was distinctly plicated internally ; it was empty . 3 . Of a young cock , eleven weeks old , examined on the 16th of June , the bursa , of a globular form , was 1 1I inch in diameter ; it communicated with the cloaca by a narrow neck about 15 inch in width ; internally it was strongly plicated ; the projecting laminie were of a crescentic form , about twenty in number , and their width , where widest , was about *4 inch . It contained some turbid fluid , in which were numerous mucus-like corpuscles and a few well-defined spermatozoa . The testes were large ; besides sperm-cells , they contained some spermatozoa . 4 . Of another cock , hatched in July , examined when nineteen weeks and six days old , the bursa , 1'2 inch in diameter , weighed 74 grs. ; it was similar to the preceding in structure , and was empty . 5 . Of a third male , hatched on the 19th of September , examined when twenty-one weeks and one day old , weighing six pounds , the bursa was 1'5 inch in diameter ; its plicae like the preceding , its opening into the cloaca large ; many spermatozoa were found in the little turbid fluid with which they were moistened . The testes were large ; the left weighed 144 grs. , the right 130 grs. ; the vasa deferentia were small . 6 . Of a fourth , hatched on the 18th of October , examinied on the 20th of March , when seventeen weeks and seven days old , weight five pounds , the bursa , compared with the preceding , was of diminished size ; its diameter only '6 inch , its plicae few , short and thick , and bloodshot ; its opening into the cloaca large and exposed , without any valvular protection . It contained a little thick mucus , in which there was commingled an appearance of spermatozoa . The testes were large , and abounded in spermcells and spermatozoa ; and the vasa deferentia were well developed , and contained a cream-like fluid rich in delicate spermatozoa* . 7 . In a fifth , a cock of about six years old , weighing four pounds and a half , no traces of a bursa could be found . The vasa deferentia were large , and were distended with a cream-like fluid abounding in spermatozoa . They terminated well apart in the cloaca , and had neither of them a visible papilla* . The right testis weighed 93'7 grs. , the left 119'7 grs. 8 . Of a young hen , hatched on the 17th of May , examined when eleven weeks old , the bursa was more flask-like than globular ; it measured 1'7 by 1'5 inch . Its plicm were large , and their glandular structure so well developed that the orifices of the follicles , as puncta , were seen with the naked eye . The bursa was empty , merely moistened with mucous fluid . 9 . Of a hen hatched on the 17th of Aarch , examined when seventeen weeks and five days old , the bursa was about the same size and form as that of the preceding ; it contained a small quantity of turbid mucous fluid , in which were seen delicate filaments bearing a resemblance to spermatozoa . 10 . Of another , hatched in May , and which , like the preceding , had never laid , examined when nineteen weeks old , the bursa , which was empty , measured 1'7 by 1'5 inch . 11 . Of a fourth , hatched on the 19th of September , said to have laid and known to have been trod , examined when twenty-four weeks old , the bursa was of shrunken appearance ; it was '5 inch in diameter ; its parietes thick ( '2 inch thick ) ; there were no plica ; it communicated freely with the cloaca , and contained a little mucous fluid in which were seen filaments like spermatozoa , but not unmistakeably such . There was a large ovum nearly ready to be detached from the ovary . A very few tolerably distinct spermatozoa were found in the oviduct , which was well developed . 12 . In a fifth , hatched on the 19th of July , examined when twenty weeks and five days old , after having laid about twenty-five eggs , no vestige of a bursa could be detected t. 13 . Of another , about eight months old , examined on the 17th of March , after having laid three or four eggs , the bursa was of a tubular form , *9 inch long by '1 wide ; its walls were exceedingly thin , and it did not communicate with the cloaca . In the little turbid mucous fluid it contained , a single spermatozoon was detected . There was a fully formed egg in the oviduct , the incrustation of which had begun . Nearest the infundibulum many spermatozoa were found . 14 . In a laying hen about three years old the bursa was reduced to a small hard mass , hardly equal to a pea in size . It contained a minute cavity without an opening into the cloaca . 15 . In another , about three years and a half old , no traces of a bursa could be detected . Its cloaca and oviduct were very large , as were also those of the preceding . II . Pheasant ( Phasianus colchicus ) . In ten examined ( seven males , three females ) , with the exception of three ( inferred to be old birds ) , the organ in question was found . It resembled in structure that of the common fowl of from four to eight months old . In each instance it was empty , merely wet with mucous fluid . These birds were shot in November , December , January , and February . Not knowing their precise age , but supposing them to have been hatched in the spring , their bursa as to size was somewhat less than that of the common fowl . The smallest , that of a hen shot in February , measured '3 inch by 2 ; it retained its plicated structure , and freely communicated with the cloaca . III . Partridge ( Perdix cinerea).-Of this bird three specimens have been examined . In one , apparently old , no trace could be found of a bursa . In the other two , in which it occurred , it resembled in form and structure that of the common fowl ; it measured *4 inch by '3 . These were young birds which had taken wing . IV . Turkey ( Meleagris gallopavo ) . In three instances of this bird , all hatched in spring , one examined in October , one in December , one in January , the bursa was found similar to that of the common fowl , and in each nearly of the same size , about . 5 inch by 7 . V. Grouse ( Tetrao scoticus ) . In a young bird , not fully fledged , just capable of a short flight , shot in the island of Lewis on the 12th of August , expressly for the purpose of examination , the bursa was found small , about the size of a pea . Air was found in its humeri , but only partially in its femora . In two , both from Scotland , later in the season , no bursa could be detected . Their femora contained air as well as their humeri . VI . Pigeon ( Columba domestica ) . In two full-grown males examined in September , no trace was found of a bursa ; in other two ( these younger birds ) the bursa was pretty large . VII . Buzztard ( Falco buteo).-Of a young one taken from its nest on the 9th of June , when about a fortnight old , the bursa was globular and comparatively large , about *8 inch in diameter , non-plicated , and empty . This nestling weighed 5193 grs. ; it was covered , except at the umbilicus , where bare , with plush-like yellow feathers , thick , very closely set , equal in weight to 647 grs. VIII . Sparrow-hawk ( Falco nisus).-Of a young bird , examined on the 31st of July , just capable of flight , weighing 3686 grs. , its sternum still cartilaginous , its humeri only partially filled with air , the bursa was small . In another , a male , apparently an old bird , shot on the 8th of March , no traces of bursa were found . It weighed 2836 grs. IX . Tawny Owl ( Strix stridula).-Of a young one taken from its nest on the 21st of June , when well fledged , but its quill-feathers not fully formed , weight 4496 grs. , the bursa was globular and comparatively large , *7 inch 1866.1 in diameter . It contained a good deal of turbid urinary fluid abounding in lithate of ammonia . It had no air in any of its bones . In an old bird , the parent of the preceding , no bursa was found . X. Cuckoo ( Cuculus canorus).-Of a young one shot on the 25th of August , weight 1310 grs. ( judging from its plumage , a bird of this season ) , the bursa was very small . In another , a male* , an older bird , shot on the 6th of June , weight 1768 grs. , no traces could be found of a bursa . XI . Common Goose.-Of one hatched in the spring , examined when about six months old , the bursa , of an ovoid form , measured 1'2 by '7 inch . It was plicated , like that of the common fowl . Of two others , one four months old , one of about eight months , the bursa was about the same size as the preceding . XII . Common Duck.--Of one , a male hatched in March , the bursa was of a cylindrical form , 1'6 inch long by *4 inch wide . Its lining membrane was without plicae ; the apertures of the mucous follicles were conspicuous , and arranged in parallel lines . It contained some dark fmecal matter similar to that in the intestine . Of another male , about three months old , the bursa was of a flask-like form , 2-6 inches in length , '6 inch in width where widest ; in structure like the preceding . It contained a turbid greyish fluid , in which were suspended granules and small globules . It was coagulated by nitric acid . Of a female , about a month older , of the same brood , the bursa resembled the last . Of another female , a little more than a year old , the bursa was very small ; its cavity was not quite obliterated , nor was its opening into the cloaca closed . Of a male about two years old , no traces remained of a bursa . XIII . Water-hen ( Gallinula chloropus).-Of a male shot in November , the bursa , of a flask-like form , was *6 inch by A4 ; its cavity was small and without plicae . XIV . Common Coot ( Ftlica atra ) . In a male shot on the 8th of Miarch no bursa was found . XV . Common Gull ( Larus canus).-The same remark applies to one examined in January . XVI . foodcock ( Scolopax rusticola ) . In two examined , one in December , the other in February , no traces of a bursa were found . XVII . Rook ( Corvus frugilegus).-Of this bird thirteen specimens have been examined . In eight no traces of a bursa were detected ; from their appearance and the quality of their bones , it was inferred that they were a year or more old . In the remaining five a bursa was met with ; three were examined in May , two in August ; all had the marks of young birds . Of one , which weighed 6132 grs. , caught when not quite capable of flight , the bursa was nearly globular and about '7 by *6 inch ; it was distended , as was also the cloaca , with a turbid fluid abounding in lithate of ammonia . Its inner surface was not plicated , but slightly pitted . Of the others , the bursa differed little from the last ; it was somewhat smaller . In the bursa of one of these some flakes were found , consisting chiefly of lithate of ammonia . XVIII . Carrion-crow ( C. corone).-Of a young male shot on the 21st of June the bursa was globular , very like that of the rook , about *7 inch in diameter ; it contained some flakes of lithate of ammonia . Of another , shot on the 30th of June , weight 6163 grs. , the bursa was somewhat different in form ; it was broadest at its base ; it measured '9 by *8 inch . Of one killed on the 16th of July , weight 5653 grs. , the bursa was smaller ; it contained some flakes of lithate of ammonia . Of a fourth , killed in February , which , judging from the smallness of the oviduct , was not an old bird , the bursa , had it not been for its opening into the cloaca , might have escaped observation , not on account of its smallness , for it was little less than that of the preceding , but from the extreme thinness of its coats and adherence to the adjoining tissues . XIX . Jackdaw ( C. monedula).-Three specimens have been examined . Two of these were old ; in neither of them was there a bursa : one was young ; it was shot on the 1 1th of July , and was fully fledged ; its bursa was pretty large , similar to that of the rook , and empty . XX . Jay ( C. glandarius).-Of one , judging from the state of its bones , hatched in spring , the bursa was comparatively large , heart-shaped , measuring ? 6 by *4 inch . Its cavity was small ; its inner surface smooth , without plicae . XXI . Blackbird ( Turdus merula).-Six different specimens have been examined . In an old bird shot in M arch , a male , no trace of a bursa was found . In an unfledged nestling , weighing 112 grs. , found dead , the bursa was so thin as to be translucent ; it was proportionally large , and contained some flakes of lithate of ammonia . In the others , which were examined between the middle of June and the beginning of October , none of them , it was inferred , more than five months old , the bursa , nearly globular , was from about '4 to *5 inch in diameter ; its lining membrane was smooth ; its parietes proportionally thick . In each instance it was empty . XXII . Song-thrush ( T. musicus ) . In an old male examined on the 28th of June no bursa was found . Of two young ones obtained on the 15th of the same month , the bursa was about the size of a large pea ; one was empty , the other contained some lithate of ammonia . XXIII . Water-ousel ( T. cinclus ) . In one , a male , probably a young one , a small bursa was found . It was shot on the 11th of November . In another , an older bird ( judging from its appearance ) , shot at the same time , there was no trace of a bursa* ; and the same remark applies to a third examined in January . XXIV . Common Starling ( Sturnus vulgaris).-Of a young one shot on the 29th of June , the bursa was about the size of that of theyoung thrush . In two old birds shot on the 7th of March , not a trace of the organ was found . XXV . Skylark ( Alauda arvensis ) . In two examined . in January there was the like deficiency . XXVI . CiZffchaff ( Trochilus minor).-Of one , a young bird , examined on the 14th of July , the bursa , of moderate size , contained a little fsecal matter . In another , an older bird , shot in March no bursa could be found . XXVII . Robin ( Sylvia rubecula).-Of a young one found dead on the 16th of June , still warm , weight 255 grs. , the bursa was of moderate size . Of another , nearly fully fledged , found dead on the 25th of June , weight 285 grs. , the bursa was comparatively large , exceeding a little in size that of the preceding . XXVIII . Yellow Ammer ( Emberiza citrinella ) . In one , a male , its testes abounding in spermatozoa , examined on the 16th of June , there was no trace of a bursa . XXIX . Blue Tit ( Parus ceruleus).-Of two young ones examined on the 8th of June , when just able to fly , one weighing 177'5 grs. , the other 162 grs. , the bursa was comparatively large ; in each it was empty . XXX . Cole Tit ( P. ater ) . In one examined in February no trace of the organ could be found . XXXI . Martin ( Hirundo urbica).-Of three young ones taken from the nest on the 10th of July , the bursa was comparatively large ; in each it was empty . One nestling weighed 414 grs. , another 398 grs. , the third 423'5 grs. The parent birds were both found of less weight ; that of the male was 263 grs. , of the female 287'4 grs. In the latter a distinct bursa was found , little less than that of the young birds . Search was made for spermatozoa , but none were found in it . Of the male , the pelvis was so injured by shot that it was useless for examination . In a male shot on the 1st of August , the testes of which contained spermatozoa , no trace of a bursa was found . From the preceding results may not the following conclusions be drawn ? 1st , That in some birds , as in the common fowl , and probably in all the gallinaceous family , and that of the Anatidme , the bursa increases in size and in completeness of organization up to a certain age , beyond which it gradually diminishes equally in both sexes , and eventually disappears . 2nd . That in other birds , those of rapid growth , which take wing as soon as they are capable of flight , the bursa is comparatively large whilst they are nestlings , does not increase conspicuously , if at all , with their growth , but rather diminishes , and after a certain age disappears , and probably sooner than in the first mentioned . The buzzard and owl are examples , and probably all birds of the same family , all of the Corvince , all of the thrush kind , and all the smaller birds , with the exception perhaps of the female martin . Of the uses of the organ , I venture to conjecture , founding my conjectures on what I have observed , that they may be provisional and various ; that in some birds , whilst nestlings , it may act the part of a urinary bladder , as witnessed in the instance of the young owl , and in some of the young rooks , crows , and thrushes , thereby tending to prevent the fouling of the nests ; that in others it may serve as a seminal reservoir at an early period , and in both male and female in the instances mentioned , in which it has been found most completely formed before the attainment of full sizein the male before the vasa deferentia are fully developed , in the female so long as the oviduct is still small and unexpanded ; and that generally , as the organ is more or less amply supplied with mucous follicles , it may serve , by the secretion it yields , to lubricate the cloaca with which it is connected , and to aid in its functions . These conjectures , or inferences , if deserving of being so considered , might be supported by what we know of the structure of the part and its position in relation to the termination of the ureters , of the spermatic vessels , and of the oviduct ; but I think it better to rest them on the facts observedthe urinary matter detected in the organ in some instances , the spermatozoa in others* , and the mucous fluid generally . But granting even that the bursa may be useful , and in the female as well as in the male , in aid of fecundation , as Fabricius supposed , yet his extreme view that that aid , in the stored-up spermatic fluid in the bursa of the hen bird , might suffice for a year , as stated in the subjoined passaget , for which and for other extracts I am indebted to the kindness of Professor Sharpey , is both highly improbable , and is opposed by the fact of the decrease of the bursa with the advancing age of the fowl , and the enlargement of the ovi* As in no instance I have yet found unquestionable spermatozoa in the bursa of the young hen , I cannot fairly infer that the bursa in the female is a receptaculum seminis ; but as in two instances there were detected in it filaments which were very like these bodies , and in one a single pretty distinct spermatozoon , and further , as the bursa seems to diminish rapidly as the oviduct becomes developed and not till then , is it not probable that for a short time it may perform the part assigned , as conjectured above ? It need hardly be remarked that the mucous secretion of the bursa adds to the difficulty of demonstrating the presence of spermatozoa . t " Semen autem Galli ad podicem immittitur , et in vesica reponitur et conservatur , quousque pullus conformetur ; immo vero per totum integrum anni tempus inibi servatur , postea quam semel admisso Gallo , ova omnia per totum illud anni tempus ftecunda redduntur , tanquam vesica unicum ob id foramen habente , ut in concluso loco semen Galli diutius ut in proprio et congrlo loco servetur."-Opp . Omnia , Lugd. Bat . 1738 , p. 21 . duct and of the vasa deferentia . Harvey , who was opposed to the notion of Fabricius , expresses the opinion that an intercourse once or twice repeated might suffice to impregnate a whole bunch of yelks , he having found that an egg laid on the 20th day of seclusion of a hen produced a chick* . This fact is an interesting one , however explained . It might be adduced in favour of the opinion of Fabricius ; but inasmuch as the passage of the fully-formed egg in the act of expulsion does not necessarily secure the expulsion of any spermatozoa previously received into the oviduct , it is of little value in the argument : and here I may mention that I have detected spermatozoa in the oviduct , even in that portion in which the egg was receiving its calcareous incrustation .
112594
3701662
Researches on Gun-Cotton.--Memoir I. Manufacture and Composition of Gun-Cotton. [Abstract]
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Proceedings of the Royal Society of London
F. A. Abel
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http://www.jstor.org/stable/112594
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Chemistry 2
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Chemistry
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III . ' Reesearches on Gun-cotton.---Memoir . Manufacture and Composition of Gun-cottono " By F. A. ABEL , F.R.S. , V.P.C.S. Received April 10 , 1866 . ( Abstract . ) A review of the researches on the production , properties , and composition of gun-cotton hitherto published , and a brief examin-ation into the probable causes of the discrepancies exhibited between the results and conclusions of different experimenters , are followed in this paper by a criticism of the several steps in the system of manufacture of gun-cotton , as prescribed by Baron v. Lenk . The conclusions arrived at on this subject are founded upon carefully conducted laboratory-experiments , and upon extensive manufacturing operations carried on during the last three years at the Royal Gunpowder Works , Waltliam Abbey . In some of these operations v. Lenk 's system of manufacture , as originally communicated to the English Government by that of Austria , was strictly followed ; in others , various modifications were introduced in different stages of the manufacture-such as in the composition of the acids used , in the proportion borne by the cotton to the acids in which it remained immersed , in the duration of the treatment of cotton with the acids , and in the methods of purification to which the gun-cotton was submitted . Exception is taken to one or two points in the general system of manufacture , and directions are indicated in which they may be advantageously modified ; but the general conclusion arrived at is that , although Baron v. Lenk cannot be said to have initiated any new principle as applied to the production of gun-cotton , he has succeeded in so greatly perfecting the process of converting cotton into the most explosive form of pyroxyline or gun-cotton , and also the methods of purification , as to render a simple attention to his clear and definite regulations alone necessary to ensure the O Opera Omnia , a Col. Aled . Lond. ed. 1766 , p. 206 . Mr. Abel on Gun-cotton . manufacture of very uniform products , which are unquestionably much more perfect in their nature than those obtained in the earlier days of the history of gun-cotton . Great stress is laid upon the fact that deviations from the prescribed process , which at first sight may appear trivial ( such as a slight modification in the strength of the acids used , the neglect of proper cooling-arrangements ) , are certain to lead to variations in the products of manufacture , affecting their explosive characters , or their permanence , or both . A considerable deviation from the normal composition , due evidently to some accidental irregularities in the course of manufacture pursued , has been exhibited occasionally by gun-cotton obtained from the manufactories at Hirtenberg and Stowmarket . The composition of gun-cotton has been made the subject of a very extensive series of experiments , both analytical and synthetical . The material employed in the analytical researches consisted of ordinary products of manufacture , prepared at Waltham Abbey , and obtained from Iirtenberg and Stowmarket . The general analytical results are as follows : Air-dry gun-cotton contains very uniformly about two per cent. of water , which proportion it reabsorbs rapidly from the atmosphere after desiccation . If exposed to a moist confined atmosphere , it will gradually absorb as much as six per cent. of water ; but it rarely retains more than two per cent. upon re-exposure to open air . The mineral constituents of gun-cotton vary according to the quality of the water employed in its purification . The average proportion of ash furnished by gun-cotton prepared at Waltham Abbey , where the water used is hard , amounts to one per cent. It should be observed that the process of " silicating " the gun-cotton , which is prescribed by Von Lenk , but the value of which is not admitted , has been applied at Waltham Abbey only in special experimental operations . Its use naturally adds to the mineral constituents contained in the finished products . The proportions of matters soluble in alcohol alone , and in mixtures of alcohol and ether , were found to be remark : bly uniform in products of manufacture obtained by strictly following Voi Lenk 's directions . In the ordinary products from Waltham Abbey , the n atter extractable by alcohol amounted to between 0'75 and 1 per cent. , and consisted of a yellowish nitrogenized substance possessed of acid characters , and evidently produced from matters foreign to cellulose ( which are retained by cotton fibre after its purification ) , and the products of oxidation which escape complete removal when the gun-cotton is submitted to purification in an alkaline bath . The average proportion of matter extractable by ether and alcohol after the alcoholic treatment is from 1 to 1'5 per cent. This consists of one or more of the lower products obtained by the action of nitric acid upon cotton-wool , the existence of which was established by Hadow . The causes of the invariable production of small proportions of these substances in the ordinary manufacturing operations , and of their existence in larger quantities in exceptional instances , have been carefully examined into . Their absolute removal from specimens of gun-cotton , purified for analytical purposes , was found to be almost impossible . The methods employed for determining the proportions of carbon , hydrogen , and nitrogen in gun-cotton , and the relative proportions of carbonic acid and nitrogen furnished by its combustion , have been very carefully tested . Four different methods of determining the carbon were employed , and forty-nine successful estimations of that element have been accomplished in a variety of products of manufacture . A number of very concordant hydrogen-determinations , and eighteen direct estimations of the volumes of nitrogen furnished by the complete oxidation of gun-cotton , have been made . The individual as well as the mean results obtained in these analytical experiments correspond much more closely to the requirements of the formula GC6 I N3 O =-C6 13 NO )1 05 trinitro-cellulose , or CG2 H0147 , 3N2 05 trinitric cellulose ) than to the formula recently assigned for gun-cotton by Pelouze and Maury , U2 H1 01 , 5 N2 0 . The determinations of the comparative volumes of carbonic acid and nitrogen have furnished results closely in accordance with those of the direct determination of nitrogen . Since the specimens of gun-cotton analyzed always retained small quantities of the products soluble in ether and alcohol , it was to be expected that the proportion of nitrogen found would be slightly below , and consequently that the carbon-results would be somewhat above , those which the chemically pure substance should furnish . The variations exhibited by the analytical results do not exceed such as are ascribable to the above cause . A number of experiments were instituted with I-Iadow 's method of determining the composition of gun-cotton , which consists in reducing the latter to cotton by means of potassic sulphydride . The results show that , although the method is useful for controlling the results obtained , by determining the increase of weight which cotton sustains by treatm-ent with nitric acid , it does not afford sufficiently definite and trustworthy data to render it applicable as a method of ascertaining the degree of perfection of manufacturing products , i. e. the extent of freedom of a specimen of the most explosive gun-cotton from admixture with the soluble varieties . The treatment of cotton with nitric and sulphuric acids has been varied in many ways in laboratory experiments , with the view to examine fully into the increase in weight sustained by the former , upon its conversion into the most explosive gun-cotton , and to determine what circumstances may exert an influence upon the amount of increase , -an acid mixture of uniform strength being employed throughout the experiments ( 3 parts by weight of sulphuric acid of spec . grav . 1 84 , and 1 part of nitric acid of spec . grav . 1'52 ) . The results arrived at may be briefly summed up as follows : Finely carded and carefully purified cotton-wool will sustain an increase of weight varying between 81'8 and 82*5 upon 100 parts of cotton , if submitted for 24-48 hours to treatment with a very considerable excess ( about 50 parts to I of cottoll ) of the acid mixture . Similar results may also be obtained by repeatedly treating the same sample of cotton for comparatively brief periods with fresh quantities of acid , provided this treatment be not too greatly prolonged . Lower results ( somewhat above or below 78 upon 100 parts of cotton ) are obtained if the cotton be submitted to treatment with a large excess of acid for only brief or for very protracted periods , or if it be left for about 24 hours in contact with a comparatively limited proportion of acid ( 10 or 15 to 1 of cotton ) . The increase of weight which 100 parts of pure cellulose should sustain by complete conversion into a substance of the formula CG H,7 N3 0,1 is 83'3 ; if converted completely into a substance of the composition 24 H36 0,8 , , 5 N2 0 , it should sustain an increase in weight of 77'78 . There is strong evidence that the differences between the highest results furnished by carefully purified cotton-wool , and the number 83'3 , are to be principally ascribed to the small proportions of foreign matter still existing in the fibre at the time of its conversion . The maximum increase of weight sustained by cotton of ordinary quality , such as is used in gun-cotton-manufacture , is , as might have been anticipated , below the result obtained , under similar conditions , with cotton of finer quality and more thoroughly purified . The highest numbers obtained by treatment of such cotton , in small quantities , with a considerable excess of acid , were somewhat below 181 , from 100 of cotton . The increase of weight which this quality of cotton sustains is , however , more generally about 78 per cent. Experiments are quoted which show that the attainment of lower results with cotton of ordinary quality is ascribable to the existence of higher proportions of foreign matters in the cotton under treatment . Some quantitative manufacturing experiments yielded results considerably below those obtained with some of the same cotton in laboratory operations ( 171 and 176 of gun-cotton having been produced from 100 of cotton ) . The causes of these differences are investigated and explained . The identity in their characters , and close resemblance in composition , of the most perfect results of laboratory experiments , and of the purified products of manufacture , the close approximation frequently exhibited by the weight of the former to the theoretical demands of the formula C6 H7I N3 01 ( which may be expressed as C{3N 02 } 0 , o , r C12 11497 , 3N205 ) , and the satisfactory manner in which the unavoidable production of somewhat lower results in the manufacturing operations admits of practical demonstration , appear to afford conclusive evidence of the correctness of K2 either of the above formulae , as representing the composition of the most explosive gun-cotton , and demonstrate satisfactorily that the material , prepared strictly according to the system of manufacture perfected byVon Lenk , consists uniformly of the substance now generally known as trinitro-cellulose , in a nearly pure condition .
112595
3701662
On the Dentition of Rhinoceros leptorhinus (Owen). [Abstract]
106
107
1,866
15
Proceedings of the Royal Society of London
W. Boyd Dawkins
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
2
32
807
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112595
null
http://www.jstor.org/stable/112595
null
null
Geography
46.909466
Anatomy 2
34.054221
Geography
[ -61.49881362915039, 52.56352996826172 ]
IV . " On the Mysteries of Numbers alluded to by Fermat . " By the Rt. Hon. Sir FREDERICK POLLOCK , Lord Chief Baron , F.R.S. , &c. Received March 19 , 1866 . [ See page 115 . ] April 26 , 1866 . J. P. GASSIOT , Vice-President , in the Chair . The following communications were read : I. c On the Dentition of Rhinoceros leptorhinus ( Owen ) . " By W. BOYD DAWKINS , M.A. , Oxon . , F.G.S. Communicated by Prof. J. PUILLIPS , F.R.S. Received March 28 , 1866 . ( Abstract . ) The fossil remains of the genus Rhinoceros found in Pleistocene deposits in Great Britain indicate four well-defined species . Of these the R. tichorhinus , or the common fossil species , ranged throughout France , Germany , and Northern Russia , and , like its congener the Mammoth , was defended from the intense winter cold by a thick clothing of hair and wool . Its southern limit in the Europeo-Asiatic continent was a line passing through the Pyrenees , the Alps , the northern shore of the Caspian , and the Altai Mountains . It has not yet been proved to have existed in Europe anterior to the deposit of the Boulder Clay . The second species , the R. megarhinus of M. de Christol , characterized by its slender limbs and the absence of the " cloison , " has been determined by the author among remains from the brick-earths occupying the lower part of the Thames valley , and from the Preglacial forest-bed of Cromer . The species ranged from the Norfolk shore southwards through Central France into Italy . In France and Italy it characterizes the Pliocene deposits , being found in the former country in association with Mastodon brevirostris and Halitherium Serresii , in the latter with IM . Arvernensis . From its southern range we may infer that the megarhine species was fitted to inhabit the warm and temperate zones of Europe , just as the tichorhine was peculiarly fitted for the endurance of an Arctic winter . The third species is the R. etruscus of Dr. Falconer , confined to the forest-bed of the Norfolk shore , and , like the R. megarhinus , found in the Pliocenes of France and Italy ; it ranged across the Pyrenees as far as Malaga , and is the only species known to occur in Spain . The fourth , the R. leptorhinus of Professor Owen , is the equivalent of the R. hemitcechus of Dr. Falconer . It is defined as " R. a narines demicloisonnees , " and is probably not the same animal as the R. leptorhinus or " R. d narines non-cloisonnees " of Baron Cuvier , the evidence as to the absence or presence of the cloison in the type of the species being of the most conflicting nature . In Central France it is identical with R. mesotropus and R. velaunus of M. Aymard , the R. Aymardi of M. Pomel , and the R. leptorhinus ( du Puy ) of M. Gervaise . Its dentition is characterized by the presence of the third costa in the upper molar series , coupled with the stoutness of the cingulum , the suppression of the anterior combing plate , the smoothness of the enamel , and the extent to which the upper molars overhang the lower , which causes the enamel on the outer side of the latter to be worn obliquely . The lower molars can be determined by the flattening of the anterior area , coupled with the fine sculpturing of the enamel-surface . In common with the other fossil British Rhinoceroses , it possessed a molar series of six only on either side , and was bicorn . It ranged through England , from the Hyaena-den of Kirkdale in Yorkshire in the north , as far south as the plains of Somersetshire , and as far to the West as Pembrokeshire . It is very generally found in association with Elephas antiquus and Iiippopotamus major , both species which lived in Pliocene times . The association in Wookey Hole Hyaena-den with Elephas primigenius and R. tichorhinus and other characteristic Postglacial mammals proves that it coexisted with the tichorhine species , to which it probably bore the same geographical relation as the Elk does to the Reindeer in the high northern latitudes . The sum of the evidence proves that it was coeval with the Mammoth and tichorhine Rhinoceros , and does not characterize deposits of an earlier epoch in the Pleistocene . It has not as yet been found in Preglacial formations . The R. leptorhinus is more closely allied to the bicorn Rhinoceros of Sumatra than to any other living species .
112596
3701662
Experimental Researches in Magnetism and Electricity. Part I. [Abstract]
107
111
1,866
15
Proceedings of the Royal Society of London
H. Wilde
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
5
49
2,202
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112596
null
http://www.jstor.org/stable/112596
null
null
Electricity
57.000663
Measurement
20.713442
Electricity
[ 29.73093032836914, -56.000892639160156 ]
II . " Experimental Researches in Magnetism and Electricity."Part I. By H. WILDE , Esq. Communicated by Mr. Faraday . Received March 26 , 1866 . ( Abstract . ) This paper is divided into two sections , the first being on some new and paradoxical phenomena in electro-magnetic induction , and its relation to the principle of the conservation of physical force ; the second on a new and powerful generator of dynamic electricity . The author defines the principle of the conservation of force to be the definite quantitative relation existing between all phenomena whatsoever ; and in the particular application of the principle to the advancement of physical science and the mechanical arts , certain problems are pointed out which , in their solution , bring out results as surprising as they are paradoxical . Although , when rightly interpreted , the results obtained are in strict accordance with the principle of conservation , yet they are , at the same time , contrary to the inferences which are generally drawn from analogical reasonings , and to some of those maxims which philosophers propound for the consideration of others . The author directs attention to some new and paradoxical phenomena arising out of Faraday 's important discovery of magneto-electric induction , the close consideration of which has resulted in the discovery of a means of producing dynamic electricity in quantities unattainable by any apparatus hitherto constructed . He has found that an indefinitely small amount of magnetism , or of dynamic electricity , is capable of inducing an indefinitely large amount of magnetism , and again , that an indefinitely small amount of dynamic electricity , or of magnetism , is capable of evolving an indefinitely large amount of dynamic electricity . The apparatus with which the experiments were made consisted of a compound hollow cylinder of brass and iron , termed by the author a magnet-cylinder , the internal diameter of which was 1inch . On this cylinder could be placed , at pleasure , one or more permanent horseshoe magnets . Each of these permanent magnets weighed about 1 lb. , and would sustain a weight of about 10 lbs. An armature was made to revolve rapidly in the interior of the cylinder , in close proximity to its sides , but without touching . Around this armature 163 feet of insulated copper wire was coiled , 0'03 of an inch in diameter , and the free ends of the wire were connected with a commutator fixed upon the armature-axis , for the purpose of taking the alternating waves of electricity from the machine in one direction only . The direct current of electricity was then transmitted through the coils of a tangent galvanometer ; and as each additional magnet was placed upon the magnet-cylinder , it was found that the quantity of electricity generated in the coils of the armature was very nearly in direct proportion to the number of magnets on the cylinder . Experiments were then made for the purpose of ascertaining what relation existed between the sustaining-power of the permanent magnets on the magnet-cylinder , and that of an electro-magnet excited by the electricity derived from the armature . When four permanent magnets capable of sustaining collectively a weight of 40 lbs. were placed upon the cylinder , and when the submagnet was placed in metallic contact with the poles of the electro-magnet , a weight of 178 lbs.-was required to separate them . With a larger electromagnet a weight of not less than 1080 lbs. was required to overcome the attractive force of the electro-magnet , or twenty-seven times the weight which the four permanent magnets used in exciting it were collectively able to sustain . It was further found that this great difference between the power of a permanent magnet and that of an electro-magnet excited through its agency might be indefinitely increased . Experiments were then made with electro-magnets of various sizes , for the purpose of ascertaining the cause of these paradoxical results . When the wires forming the polar terminals of the magneto-electric machine were connected for a short time with those of a very large electromagnet , a bright spark could be obtained from the electro-helices twentyfive seconds after all connexion with the magneto-electric machine had been broken . Hence it is inferred that an electro-magnet possesses the power of accumulating and retaining a charge of electricity in a manner analogous to , but not identical with , that in which it is retained in insulated submarine cables , and in the Leyden jar . It was also found that the electro-helices offered a temporary resistance to the passage of the current from the magneto-electric machine . When four magnets were placed on the cylinder , the current from the machine did not attain a permanent degree of intensity until an interval of fifteen seconds had elapsed ; but when a more powerful machine was used for exciting the electrohelices , the current attained a permanent degree of intensity after an interval of four seconds had elapsed . The general conclusion which is drawn by the author from a consideration of these experiments is , that when an electro-magnet is excited through the agency of a permanent magnet , the large amount of magnetism manifested in the electro-magnet , simultaneously with the small amount manifested in the permanent magnet , is the constant accompaniment of a correlative amount of electricity evolved from the magneto-electric machine , either all at once , in a large quantity , or by a continuous succession of small quantities , the power which the metals ( but more particularly iron ) possess of accumulating and retaining a temporary charge of electricity , or of magnetism , or of both together ( according to the mode in which these forces are viewed by physicists ) , giving rise to the paradoxical phenomena which form the subject of this part of the investigation . Having established the fact that a large amount of magnetism can be developed in an electro-magnet by means of a permanent magnet of much smaller power , it appeared reasonable to the author to suppose that a large electro-magnet excited by means of a small magneto-electric machine could , by suitable arrangements , be made instrumental in evolving a proportionately large amount of dynamic electricity . Two magnet-cylinders were therefore made , having a bore of 2inches , and a length of 121 inches or five times the diameter of the bore . As frequent mention is made of the different-sized machines employed in these investigations , they are distinguished by the calibre , or bore of the magnet-cylinders . Each cylinder was fitted with an armature , round which was coiled an insulated strand of copper wire 67 feet in length , and 0'15 of an inch in diameter . Upon one of the magnet-cylinders sixteen permanent magnets were fixed , and to the sides of the other magnet-cylinder was bolted an electromagnet formed of two rectangular pieces of boiler-plate enveloped with coils of insulated copper wire . The armatures of the 2--inch magnetoelectric and electro-magnetic machines were driven simultaneously at an equal velocity of 2500 revolutions per minute . When the electricity from the magneto-electric machine was transmitted through a piece of No. 20 iron wire 0'04 of an inch in diameter , a length of 3 inches of this wire was made red-hot . When the direct current from the magneto-electric machine was transmitted through the coils of the electro-magnet of the electromagnetic machine , the electricity from the latter melted 8 inches of the same-sized iron wire as was used in the preceding experiment , and a length of 24 inches was made red-hot . When the electro-magnet of a 5-inch machine was excited by the 2'-inch magneto-electric machine , the electricity from the 5-inch electro-magnetic machine melted 15 inches of No. 15 iron wire 0'075 of an inch in diameter . The author having found that an increase in the dimensions of the machines was accompanied by a proportionate and satisfactory increase of the magnetic and electric forces , a 10-inch electro-magnetic machine was constructed : the weight of its electro-magnet is nearly 3 tons , and the total weight of the machine is about 4tons . The machine is furnished with two armatures-one for the production of " intensity"- , and the other for the production of " quantity"-effects . The intensity armature is coiled with an insulated conductor consisting of a bundle of thirteen No. 11 copper wires , each 0 125 of an inch in diameter . The coil is 376 feet in length , and weighs 232 lbs. The quantity armature is enveloped with the folds of an insulated copperplate conductor 67 feet in length , the weight of which is 344 lbs. These armatures are driven at a uniform velocity of 1500 revolutions per minute , by means of a broad leather belt of the strongest description . When the direct current from the 1-5inch magneto-electric machine , having on its cylinder six permanent magnets , was transmitted through the coils of the electro-magnet of the 5-inch electro-magnetic machine , and when the direct current from the latter was simultaneously , and in like manner , transmitted through the coils of the electro-magnet of the 1 0-inch machine , an amount of magnetic force was developed in the large electromagnet far exceeding anything which has hitherto been produced , accompanied by the evolution of an amount of dynamic electricity from the quantity armature so enormous as to melt pieces of cylindrical iron rod 15 inches in length , and fully one-quarter of an inch in diameter . With the same arrangement , the electricity from the quantity armature also melted 15 inches of No. 11 copper wire 0 125 of an inch in diameter . When the intensity armature was placed in the magnet cylinder , the electricity from it melted 7 feet of No. 16 iron wire 0'065 of an inch in diameter , and made a length of 21 feet of the same wire red-hot . The illuminating power of the electricity from the intensity armature is , as might be expected , of the most splendid description . When an electric lamp , furnished with rods of gas-carbon half an inch square , was placed at the top of a lofty building , the light evolved from it was sufficient to cast the shadows from the flames of the street-lamps a quarter of a mile distant upon the neighbouring walls . When viewed from that distance , the rays proceeding from the reflector have all the rich effulgence of sunshine . A piece of the ordinary sensitized paper , such as is used for photographic printing , when exposed to the action of the light for twenty seconds , at a distance of 2 feet from the reflector , was darkened to the same degree as was a piece of the same sheet of paper when exposed for a period of one minute to the direct rays of the sun , at noon , on a very clear day in the month of March . The extraordinary calorific and illuminating powers of the 10-inch machine are all the more remarkable from the fact that they have their origin in six small permanent magnets , weighing only 1 lb. each , and only capable , at most , of sustaining collectively a weight of 60 lbs. ; while the electricity from the magneto-electric machine employed in exciting the electro-magnet was of itself incapable of heating to redness the shortest length of iron wire of the smallest size manufactured . The production of so large an amount of electricity was only obtained ( as might have been anticipated by the physicist ) by a correspondingly large amount of mechanical force ; for it was found that the large electromagnet could be excited to such a degree that the strong leather belt was scarcely able to drive the machine . When the electro-magnet of the 10-inch machine was excited by means of the 21-inch magneto-electric machine alone , about two-thirds of the maximum amount of power from the 10-inch machine was obtained . From a consideration of the combined action of the magneto-electric and electro-magnetic machines , the author points out a remarkable analogy , subsisting between the operation of the static forces of magnetism and of cohesion in modifying dynamical phenomena , which throws additional light upon the nature of the magnetic force . On reviewing and comparing the whole of the analogous phenomena manifested in the operation of the magnetic and cohesive forces under the varied conditions to which the author invites attention , it appears to him that magnetism is a mode of the force of cohesion , or is , if the term be allowed , polar cohesion acting at sensible distances , the equivalent of magnetic force being obtained at the expense of an equivalent of ordinary cohesive force ( in an axial direction ) so long as the iron continues to be magnetized .
112597
3701662
Extract of a Letter from Charles Chambers, Esq., Acting Superintendent of the Bombay Magnetic Observatory, to the President. Dated March 28, 1866
111
114
1,866
15
Proceedings of the Royal Society of London
Charles Chambers
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0027
null
proceedings
1,860
1,850
1,800
4
30
1,017
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112597
10.1098/rspl.1866.0027
http://www.jstor.org/stable/112597
null
null
Meteorology
54.152895
Biography
30.009382
Meteorology
[ 56.78010559082031, 13.251994132995605 ]
III . " Extract of a Letter from CHARLES CHAMBERS , Esq. , Acting Superintendent of the Bombay Magnetic Observatory , to the President . Dated March 28 , 1866 . " Communicated by the President . Received April 26 , 1866 . You will probably have heard from Mr. Stewart that the opportunity of applying usefully the experience which I acquired at Kew has been tem porarily accorded to me by the Bombay Government , by my appointment to the superintendence of this Observatory . The confirmation of my present appointment will probably depend upon the sanction of the scheme of improvements for the Observatory which I have just sent in for the consideration of Government . Meanwhile I have arranged the working power of the establishment so as to take up the reduction of the old observations , and I am sure you will be interested to learn that there is a probability of their turning out trustworthy and valuable . The separation of seven years of declination-disturbances has already been effected , with the results shown in the enclosed Tables and Curves ; but as the whole series of observations ( from 1845 to 1865 ) will include two complete cycles of the decenniaI period , and as the reductions have already been so long delayed , I propose completing the twenty-one years before discussing the connected questions and publishing the whole ; it is , however , a little doubtful whether the opportunity of doing this will be afforded me , as the Indian Government , in sanctioning my appointment , have limited its duration to the end of next month ; and though I am hopeful that , partly in consequence of a representation that I have made to the Government , of the wide scope for usefulness that is open to me here , and of what has been effected and has been engaged upon since my arrival six months ago , they may be induced to extend their approval of the appointment until the improvements suggested in my Report shall have been considered , yet it seems right , as there are some interesting points about the results already arrived at , that I should inform you of them whilst I may , especially as in case of a second reference of the matter to the home Government , you will , I believe , consider them good grounds upon which to recommend the continuance of the reductions of the twenty-one consecutive years of the Bombay observations . Referring to page 283 of your paper in the Philosophical Transactions , 1863 , it will be seen that these results supply the required knowledge of the laws of the disturbances at a station intermediate in longitude between Kew and Nertschinsk . The general characteristics of the westerly disturbancediurnal-variation curve are the same as you describe for Pekin and Nertschinsk . The curve is remarkably regular , and the ordinates between 8 P.M. and 4 A.M. have scarcely appreciable values , being in the latter respect like the westerly curve for Hobarton , and the easterly for Kew and St. Helena . The maximum occurs at 11 A.M. , which corresponds to about 18 " Kew astronomical time , implying , by comparison with the corresponding hours of maximum at the other two eastern stations ( Pekin and Nertschinsk ) , a rather slow propagation of the disturbing action from north to south of the eastern part of the northern hemisphere . The other curve ( of easterly disturbance ) presents a less systematic appearance ; and the ratios are at no part of the day smaller than 0'64 , or greater than 1-83 . The Table of aggregate values of disturbance in the several years points very distinctly to a minimum as occurring early in 1864 , thus adding another to the determinations of this turning-point in three former cycles given by you in the third volume of the ' St. Helena Observations , ' and confirming the conclusions you arrived at as to the propriety of the appellation " decennial " to the period in question . The Table does not extend far enough backwards to fix the time of maximum distinctly , but it suffices to place it with probability in the year 1859 . The principal requests that I have made in my Report are for a--set of Kew magnetographs , and for a suitable room , and for a body of computers to work up the old observations . Ratios of the aggregate values of the declination disturbances Astronomicl ho exceeding 1'4 in amount at the several hours in the seven years from 1859 to 1865 inclusive . Kew Westerly Easterly ( approximate ) . disturbances . disturbances . 12 7 '05 '70 13 8 '17 ' 68 14 9 '16 -64 15 10 -14 '84 16 11 -18 -69 17 12 '36 '71 18 13 '80 -92 19 14 '96 1-17 20 15 1-64 1 00 21 16 2-35 1'08 22 17 2-73 1-61 23 18 2-76 1-83 0 19 2-84 1-68 1 20 2-57 1-56 2 21 1-86 1-29 3 22 1'41 ' 99 4 23 1'06 '91 50 '61 -85 61 '40 -85 72 '45 -80 83 -16 1'00 94 '11 '79 10 5.16.70 11 6 -08 '72 Aggregate values in the seven years ... ... ... ... ... ... ... ... ... 2801-1 4538'7 7339-8 113 Ratios of disturbance in the Aggregate values of all disturbseveral years from 1859 to ances exceeding 1-4 in the in e to te m 1864 inclusive to the mean . several years from 1859 to aggregate disturbance in the aggregate disturba-nce in the 1865 inclusive . 8six years taken as unity . Years . Aggregate Years . values . Years . Ratios . 1859 1A43 1859 1532-1 1860 1-33 1860 1421-6 1861 0-89 1861 9518 1862 1-16 1862 1240-5 1863 0-64 1863 691-1 1864 0-56 1864 595-9 1865 906-8 The ratio of the maximum in 1859 to the minimum in 1864 is as 2-6 to 1 .
112598
3701662
On the Tides of the Arctic Seas.--Part III. On the Semidiurnal Tides of Frederiksdal, near Cape Farewell, in Greenland. [Abstract]
114
114
1,866
15
Proceedings of the Royal Society of London
S. Haughton
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
1
16
169
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112598
null
http://www.jstor.org/stable/112598
null
null
Meteorology
35.831973
Geography
34.263762
Meteorology
[ 48.17562484741211, 28.07895851135254 ]
IV . " C On the Tides of the Arctic Seas.-Part III . On the Semidiurnal Tides of Frederiksdal , near Cape Farewell , in Greenland . By the Rev. S. HAUGHTON , F.R.S. Received April 12 , 1866 . ( Abstract . ) The observations discussed in this paper by the Rev. Dr. Haughton were made for him ( in 1863-64 ) , at the request of Admiral Irminger of the Royal Danish Navy , by Missionary Asboe , at Frederiksdal , near Cape Farewell in Greenland . They proved amply sufficient for the complete discussion of the semidiurnal tide of that interesting locality ; and the following results were obtained:1 . Eccentricity of lunar orbit ... ... ... ... ... ... . . 0'06786 2 . Mass of earth as compared with mass of moon ... . 64'638 3 . Depth of Atlantic deduced from heights ... ... . 10-03 miles . 4 . Depth of Atlantic deduced from times ... ... ... . 3'30 miles .
112599
3701662
On the Mysteries of Numbers Alluded to by Fermat. [Abstract]
115
127
1,866
15
Proceedings of the Royal Society of London
Frederick Pollock
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
14
151
6,772
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112599
null
http://www.jstor.org/stable/112599
null
null
Formulae
70.195223
Measurement
10.757118
Mathematics
[ 87.19542694091797, -23.346704483032227 ]
" On the Mysteries of Numbers alluded to by Fermat . " By the Rt. Hon. Sir FREDERICK POLLOCK , Lord Chief Baron , F.R.S. , &c. * ( Abstract . ) This paper is presented as a continuation of one which appeared in the Philosophical Transactions of the Royal Society for 1861 , vol. cli . p. 409 , and the object of it is to call attention to certain properties of odd numbers when placed in a square , according to an arrangement to be explained below . It appears to me probable that these properties are connected with ( if , indeed , they be not actually some form of ) the mysterious properties of numbers , to which Fermat alludes in the announcement of his theorem ( as furnishing the proof of it ) ; for in point of fact these properties give a method by which every odd number can be divided into four square numbers , and every number ( odd or even ) can be divided into not exceeding three triangular numbers . I am not prepared to say whether or not the method affords a demonstration , and proves that it can always be done ; but it always does it , and the cause of its success may be distinctly shown . The properties I allude to are scarcely less interesting and curious than the theorem itself , and present results for which I can find no namne more appropriate than the geometry of numbers , for relations appear to be established between various numbers in the square , which relations are not founded on any arithmetical connexion between them , but on the positions they respectively occupy in tne square of which they form a part . The arrangement of the numbers is as shown in diagram No. 1 . Any odd number ( which may be the subject of inquiry ) is made the first term of a series , increasing from left to right by the numbers 4 , 8 , 12 , 16 , ... ( 4 n ) This series forms the horizontal line at the top ; each term of the series so formed is made the first term of a series , increasing downwards by the numbers 2 , 6 , 10 , 14 ... . ( 4n-2 ) . A square of indefinite magnitude is thus formed , consisting of two sets of series , one set all horizontal , the other set all vertical . 161 is the first number in diagram No. 1 . The result of the arrangement of the two series in the manner above mentioned is the formation of a third set of series , which may be found in the diagonal lines of the square . If from the first number in the square ( 3 a diagonal linie be drawn towards the opposite corner , it will pass ugh the first terms of one portion of the third set of series ; the second , third , and following , terms are takeni alternately from each side of the diagonal line . These series increase by 2 , 4 , 6 , 8 , &c. ... ( 2n ) , and with the exception of one term they are all in the diagonlal lines ( see diagram No. 1 ) , in which the single red line passes through the first terms , and the double red line shows where the terms of the series ( the second , third , &c. ) belonginog to that ( as a first term ) are to be found ; the red inik numbers indicate their order . 12345678 The Nos. 203 , 205 , 209 , 215 , 223 , 233 , 245 , 259 , &c. , &c. , compose the series ; the terms increase by 2 , 4 , 6 , 8 , 10 , &c. ... 2n . Any number in the diagonal from 161 may be the first terni of a similar series . The diagonal from 163 will give all the other first terms of the third set of series . In order to explain the indices which appear in the diagram No. 1 , and to show in what manrner the series are connected with , and pass into each other , it is necessary to point out the properties of the two series which compose the square , and of the third series , which is a niecessary result . All of them have this property in common , -that if you can discover the roots of the squares which compose any term of the series with reference to the nature of the series , and the order in the series of that term , then you know the roots of every term in the series , both before and after that term . The first series iniereases by 4 , 8 , 12 , &c. The indices of the terms of a series so increasing I have made 1 , 3 , 5 , 7 , &c. , and they are put at the top as being comimoni to all the series that are horizontal . For this reason , if two numbers differ by 1 , as n , nz+ 1 , and the larger be iniereased by 1 , and the smaller be diminiished by 1 , and the process be continued , the result will be . 21 , n+ 1 , n-1 , ? I +-2 , nz-2 , n+3 , n-3 , n ? +4 , &c. &c. n--(p-1 ) n+p . If these be treated as roots , the sums of the squares will be 2 2+ 2 + ? I. 2n'+22z+5 , 2n2+2n+ 13 , 2n2 ? + 2n + 25 , &c. &c. 2n2+2n+ 2P2_2p + 1 . The sums of the squares inierease by 4 , 8 , 12 , &c. If therefore the roots of the square , into which any odd number may be divided , bep , q , n , n+ 1 , and the number be increased by 4 , 8 , 12 , &c. ... ( 4n ) , the mnth term in the series will be composed of squares whose roots will be p , q , n-(n-1 ) , n + m ; two of the roots will be constant , the others will vary , and their differences in the successive terms will be 1 , 3 , 5 , 7 , &c. ( 2n1 ) ; and if you discover the roots of any term in the series , you can find the roots of all the terms . The second series resembles the first in having two roots constant , and two variable ; the differences between the variable roots are , in the first term 0 , in the second term 2 , in the third term 4 , &c. , and the indices of the terms are therefore 0 , 2 , 4 , 6 , 8 , 10 , &c. , which are placed vertically by the side of the square . For if two numbers are equal , as ni , An , and one of them be inclreased by 1 , and the other diminished by 1 , and the process be continued , the result will be nn 2z n-1 , n+1 j If these be treated as 2N2 ? +2 n-2 , n+2 > roots , the sunms of < 2n'+S n-3 , n+3 their squares will be 2n 'd 18 &c. & C. J & C. &c. The sums of the squares increase by 2 , 6 , 10 , 14 ... . ( 4nz-2 ) , and the successive differences of the variable roots are 0 , 2 , 4 , 6 , &c. ; and if the roots of the squares inito which any odd number may be divided be p , q , n , z , and the number be increased by 2 , 6 , 10 , &c. , the roots of the mth term will be p , q , n-(mr-l ) , n ? +(n-l ) , and if the roots of any one term be known , the roots of all the others may be found . The small figures in the upper right-hand corner of each division or small square are the indices of the third set of series . In this set all the roots are variable . The character of the first set of series is , that two roots in every term differ by an odd number ; the character of the second set of series is , that two roots in every term differ by anl even number ; but in the third set of series , the algebraic sum of all the roots of the squares into which the successive terms may be divided is successively 1 , 3 , 5 , 7 , 9 , &c. ( an odd number ) : the sum of the roots of the squares into which an odd number can be divided cannot be an even number . The following Table will explain in what manlner the series is formed from the ropts of the squares into which any odd number may be divided , so as to make the algebraic sum equal to 1 . I have preferred to use figures instead of algebraic symbols , as being more readily understood and more easily dealt with ; but the result is the same whatever figures or symbols may be used . The series begins from the centre . Let-7 , -3 , 2 , 9 , which are the roots of the squares into which the odd number 143 may be divided , be placed in the centre , and let the positive roots be increased downwards and decreased upwards , and the negative roots increased upwards and decreased downwards , the result will be as in the Table below : Order of Algebraic Sums Order of Roots . sums of of squares of terms . roots . of roots . terms . 457 12 -13-9-4 3 -23 275 12 10 -12-8-3 4 -19 233 10 8 -11-7-2 5 -15 199 86 -10-6-1 6 -11 173 64 9-5 077 155 42 8-4 183 145 2 Centre 1 7-3 291 143 13 6-2 3710 5 149 3 5-1 4 11 9 163 574 05 12 13 185 79316 13 17 215 911227 14 21 253 11 13 1-3 8 15 25 299 13 &c. &c. &c. It will be observed that the terms of the series 143 , 145 , 149 , 155 , &c. increase by 2 , 4 , 6 , 8,. . ( 2 n ) . In the column of the sums of the roots 1 , 5 , 9 , 13 , &c. increase by 4 . 1 , -3 , -7 , lII decrease by 4 ; the differences of the roots , if arranged in the order of their numerical value , is always the same throughout the series . Note . In the remainder of this paper every odd number that becomes a term in any of the series is expressed by the roots the sum of whose squares form the number itself ; 2 , 3 , 6 , 8 means that the number occupying that division or small square is 113= ( 22+32+ 62+8 ) ; a figure ( or collection of figures ) representing , merely the arithmetical value is put into it circle , thus : 2 , 3 , 6 , 8 Having explained the construction of the square and the indices which belong to the series of which it is composed , I propose to point out the properties which discover the roots of the squares into which the odd numbers ( which are found in the different parts of the square ) may be divided . If the first odd number in the square be of the form ( 4 p+ 2 ) . n+1 ( or 2 n+ 1 , 6 n+1 , 10 n+l , 14 n+1 , &c. ) , n being of any value whatever , the ( n-p)th term will be ( p+ l ) , -p , n , n j ; these are the roots ( the number itself would be 2 n2 ? ? 2p2 + 2p + 1 ) ; and as the index of the nth term is n+(n-1 ) , or 2n-1 , the inidex of the ( n-p)th will be 2 n-(2 p+ 1 ) , and the algebraic sum of the roots may be made equal to the index ; it is therefore a term in a diagonal series Lthat the ( n-p)th term is 2 n+ 2 2p2+ 2p+ 1 , will appear by finding in the usual way the ( n -p)th term of a series whose first term is ( 4 p+ 2 ) . n+ 1 , and the terms of which increase by 4 , 8 , 12 , 16 , &c. ... 4 n ] ; but as two of the roots are cqual , n , n , it is the first term of a vertical series descending , thus : p+ l , p , n , n p++ p , ( n-1 ) , n+1 p+I , p , ( n-2 ) , n+2 p ? + p , , ( n-3 ) , ( n+3 ) . I call this term ( A)* and indicate it by that letter , and from this term the roots of many others may be derived ( which are indicated by other letters connected with A in an invariable manner ) , whose squares will compose the number that belongs to that term . For example , counting 2p ? ? 1 squiares backwards from A is a term I have distinguished as W ; the roots of the number belonging to it are p +1 , ) , ( n)-4p+2 ) , n These roots may , of course , be either positive or negative ; arranging them thus , -p-+ 1 , -p , 4p+ 2 , n , we have the algebraic sum of their roots equal to 2 n6 p+ 3 , which is the index of the square in which W is found going backwards from A , the index of which is 2 n2p +1 ( as already stated ) ; immediately adjoining W are two squares which I have called M and N respectively . M is the term next before W , and is composed of the roots n-2p ? ? ? ?+2 , it-2 p+2 , 3p+2 , p+ 1N is the term next after W , and consists of the roots n-21p , n-2p , 3p+l , p1 Each of these will traverse the squiare diagonally , the algebraic sums of their roots beirig equal to the index ; the roots of W may also be obtained from A by takin-g its roots dowln vertically , making n , n , successively n1 , n+1 , n-2 , + 2 , &c. , until the square is reached , in which the index is 2 n+ 2p+ 1 , and 2 i+ 2p+1 being the arithmetical sum of all the roots of A ; A here becomes a term in a series which moves diagonally , and on being carried up towards the left will give the roots of W. Whclu the indices of the squares through which this vertical series passes equal 2n+ 1 , by makingjp + 1 , p , one positive and the other negative , the term becomes a term in another series which moves diagonally upwards towards the left . This must occur both when the index equals 2 tI and when it equals 2n +1 ; and as the indices increase downwards uniformly by 2 , it follows that 2 ni-1 and 2 n+ 1 will be the indices of contiguous terms of the vertical series , and therefore two contiguous terms will become terms of series moving diagonally upwards to the left ; and as these two series are contiguous to each other , their terms found in the first series ( that is , the series in the top line ) will also be contiguous . These two terms I have designated as AM and AN . AM comes from the term where the index equals 2 n+ 1 , and AN from the terii where the index equals 2 n1 ; the roots of AAI are 0 , 2p+1 , 2-1)n2 , those of AN are 0 , 2 +l , m-2p , I ' andi being arranged thus , --2 )+ 1 , 0 , m-2p+ 2 , it , -2 p+ 1 , 0 , m-2p2 , m , will move diagonally downwards to the left ; and as each of these have two r'oots that differ in onae case by 2 I , in the other by 21+ 2 , the terms in these series that arc parallel to those terms in the first vertical series which have their externlal indices respectively 2 1 ) and 2p+ 2 , the terms of A:iV and AN will ( I say ) in these places become terms in series movirig vertically ; and on being followed up to the series in the top row will be found to give the roots of TMI and N. The roots of MA and N may be -obtained by another method as follows:-As the algebraic sum of the roots of A equals its index , therefoie A is a term in a diagonal series moving downwards towards the left ; and as two of its roots , p ) , i ) + 1 , differ by 1 , it follows that whenever the value of m has been so altered that 2n+1 equals the inidex by making + 1 , p , one positive and the other negative , the term becomes a term in another series , which series will move at right angles to the series last mentioned . Now taking the series which moves to the left of A , it is clear that this result will obtain in . two places ; first , whern the altered value of i makes '2 -1 equal the index , and secondlv , when the altered value of n makes 2 n+1 equal the index . The first of these going up gives the roots of N , the second gives those of M , and these roots are identical with those obtained from AM and AN . The index of A is 2 i2 p+ 1 , therefore when n in moving downwards becomes n+1 , n+2 , + ? 3 ... ... . . 2nz-3 p-F2.2 n-3_p+l + 1 , p being two of the roots of each term in this series ; by adding , p ? ? 1 to the first-mentioned root and p to the other , these two terms will be found to be terms in two horizontal series , of which the first terms are in the first vertical series , and these terms both of them make the diagonal index , and therefore are terms in a diagonal series which , rising towards the right , give the roots of W. A descends diagonally to the left , and on each side of the line which leads to W changes to cross diagonals which lead to M and N. W leads diagonally to the left to R and S , and where it crosses AT changes and goes up to A. M goes down into R , and then diagonally to where it meets the horizontal series from T ; its roots there correspond with the series from T ; it returns to T and uip to A. In like manner N goes down through S to the line from V , and so to V and up to A. R and S go each of them across to the vertical line from A , and so up to A : every term through which these lines pass has the four roots indicated whose squares would make the term . The number of terms in the whole square , whose four roots may be expressed in term of p and n , is very considerable ; and it may be well now to present some skeleton diagrams of the many ways in which certain members of the square are in7varia.6y connected . I propose to exhibit several ( to avoid confusion , which would arise from putting all in one diagram ) ; these do not by any means include all the connexions that exist ; but whatever may be the value of n or p , a number of the form ( 4p+2).n+1 , whether it be 2n+1 , 6n+l , OnX+1 , &c. , and whatever be the value of et , gives the following resuilts . See diagram No. 2 . At the ( n-p)th term there will be A , which descends vertically till the index is 2n1 , then 2n+ 1 , and from these rise up in diagonals AN and AM , as already mentioned . A then further desceinds till the index is equal to 2n + 2p + 1 , when it rises in a diagonal to W. Diagram No. 3 shows certain connexions between AM and AN and other terms in the square . AMt is always -2p-+1 , 0 , n-2pp+2 , ? n , AN is always -2p + 1 , 0 , n -2p , n. If the series in which AMN is a term be carried down diagonally till 0 becomes 2p +1 ( that is 2p +1 places ) , it becomes a term in a diagonal series that intesects it and rises to the top , then goes down to the horizontal series from It , where it becomes a term in that series and passes to where it is below M and rises vertically up to it . AN does the same with respect to the series from S , and rises up to N. If the term AM descends till n 2p +2= 2p 1 , it rises to the left in another diag , onal series and goes on till it crosses M , where it is foiind that the roots are always the same as those which arise from M , descending by means of its two eqiual roots . The term AN does the same with respect to N. If AMIf descend to the margin at am , and one step further into an , and AN descends to an , they will be found to have the same roots , and they will be _ from AMi _ -2p+l , 1 , n-2p+1 , n from AN -2p+ 1 , -l , n-2p+1 , n The only differenice being that in the one case 1 is positive , in the other it is negative ; but whatever be the value of p or n , in this portion or term of the square 1 is always one of the roots . In crossing the two horizontal series from R and S , it will always be found that at the points of intersection the roots of AMi corresponed with the roots of the series from I , and the roots from AN correspond with those from S. Diagram No. 4 exhibits the way in which B , C , P , and Q are connected together . The roots of A at the ( it-p)th square will always be -(+ 1 ) , -p , n , n , aidp ? + 1 , p must be one of them odd , the other even ; therefore , whether n be odd or even , ain odd number will be formed by -(p+ 1 ) , t , or -p , n. The series from A descending diagonally has the roots it , i decreasing , but the niegative roots iniereasing . The differences will continue the same ; and when the series arrives under that index which corresponds to the odd number -(1-)+ 1 ) n , or --p , n , it becomes a term in a horizontal series which goes to P , two terms of which are always p , p+ 1 . W , in descending diag , onally , has its index on reaching PB 1 . When A has descenided so as to reach the evenl number of the two , ( -(p+1 ) , n , -_ ) , n ) , it rises in a vertical series to Q ; and the three series , WR . , BP , CQ , always intersect in the same point or small square , H. The paper then exhibits in a Diagram ( No. 5 ) all the roots which arise from applyij g the method to the odd No. 161 , and shows that the roots of A would be ... ... . . 3 , 2 , 16 , 16 ofW ... ... ... ... . . 3 , 2 , 6 , 16 of Mt , ... ... ... ... . 8 , 3 , 10 , . 10 of N , , ... ... ... ... . 7 , 2 , 12 , 12 of AM , ,5 , 0 , 10 , 16 of AN , ,.5 , 0 , 12 , 16 It shows the roots of the squares marked B , C , P , Q , R , S , and many others ; and , finally , it showrs that 161 would be composed of the squares of the following roots , either 3 , 12 , 2 , 2 , or 10 , 0 , 5 , 6 ; but to set forth the roots of the numbers which are iu Diagram No. 1 , would require a diagramn larger thaui could conveniently be put into a publication of the size of the Proceedings . The roots 10 , 0 , 5 , 6 , if arranged thus , -10 , 0 , 5 , 6 , have 1 for their sum ; but it was proved in the former paper ( see p. 410 , Trans. Roy . Soc. for 1861 ) that if the algebraic sum of the roots be 1 , then the number is the double +1 of a number composed of 3 triangular numbers , 16 1=80 x 2+1 , and 80 is composedof the 3 triangular numbers 55 , 15 , 10 . If therefore any number be doubled , and 1 be added , aln odd number will be obtained , to which the same process may be applied as is here applied to 161 . I have stated that the cause of the success of " the method " ( though it does not at present amounit to a demolnstration ) may be easily slhown . It arises , first , from " the mnethod " requiring every odd number that is a term in any of the series to be represented by the roots of the square numbers that compose it ; and secondly , and more particularly , from every series being connected with at least six others of a different kind which intersect it , each of which is again connected with at least five others , so that when the whole nietwork has been pursued , and the roots which in successioni form every term have beeni recorded , it will be fouild that many different modes of dividing each term into four squares or less will be discovered , i. e. if the numbers be large . I propose to show the manner in which the series are apparently interwoveli by an example from each kind . 21 23 Let the first term in a horizontal series be 22 3 , 7 , 13 , 14 with 22 as the index in the margin , and 21 and 23 being , the indices of the diagonal series which pass through this square ; for , except at the top line , two diagonal series pass through every square . 13 and 14 are the variable roots , which become 12 , 15 , 1 11 , 16 , 1 10 , 17 , 1 9 , 18 , l &c. t in the successive terms ; when in the second term 14 becomes 15 ( 15+7=22 ) , and the roots are 3 , 7 , 12 , 15 , a term in the series which would come down from the second square ; the roots in that square will therefore be 3 , 12 , 4 , 4 ; when 15 becomes 19 the roots will be 3 , 7 , 8 , 19 , and the roots at the top will be 7 , 8 , 8 , 8 ; so when 15 becomes 25 at the tenth term the roots are 3 , 7 , 2 , 25 ; and as 3 , 25=22 , another series rises up with roots of the first term , 7 , 2 , 14 , 14 . 13 diminishes to 0 , and then increases , giving 2 more when it becomes 15 or 19 ; but the series is also crossed by diagonal series ; and when the 21 19 17 iS 13 , & cj.3 index in the two rows from the first term 23 25 27 29 31 , &c. is37 ( the sum of all the roots ) , or 31 ( the sum of the variable plus the differenlce of the constant roots ) , or 17 ( the sum of the variable roots minus the sum of the constant roots ) , or 23 ( the sum of the constant roots minus the difference of the variable ) , a diagonial series arises . Hlere are no less than 10 other series by which this is crossed and associated and connected , and the number cannot in any case be less than 6 . A series of the second kind gives rise to other series crossing it in the same manner mutatis mnutandis , which result is so obvious that it is not necessary further to dwell upon it . A series of the third kind has all the differences of its roots the 13 same in each term . Let -7 , 2 , 4 , 14 be a term in a diagonal series at the top row of the system . 11 13 15 92 10 0 8 , 13 , 2 , 2 -7 , 2 , 4 , 14 6 , 15 , 4 , 4 Thus : __9 ~~~~~~~~~17 92 10 92 To 2 -8 , 1,3 , 13 -6 , 3 , 5 , 15 When it reaches to the left and to the right , the second place , as 3-1=2 and 5-3 2 , it furnishes two vertical series ; at the tenth row it furnishes two more ; at the twelfth row two more . Wheni it gets into the column whose index is 11 and then 9 , before it reaches the margin or outer edge , it furnishes two horizontal series ; and after it has passed the margin at 9 and 11 it furnishes two more , and at 21 it furniishes another . Here are six new vertical and five new horizontal series ; besides which it fiurnishes at least two other diagonal series which cross it . Having stated the properties which belong to the square , if the first odd number in it be of the form ( 4p + 2).n ? ? 1 , and that whether it be 2n + 1 , 6n ? ? 1 , l On ? ? 1 , &c. , or whatever be the value of ni , certain squares may be found which I distinguish as A , B , C , H , P , Q , W , M , N , AM , AN , R , S , T , V , &c. , which are connected together by a community of roots where the series cross each other in a manner that is invariable . The Diagram No. 3 is another example of the manner in which certain of the terms in the different series communicate with each other , by the roots being comMon to both , at the point where they cross . AM passes diagonally to am , down to an , and up to AN . AN , in like manner , goes down to an and up to am and AM . If the first term of the square be an odd number of the form ( 4p+2 ) n+1 , the roots from AM are in an -(2p + 1 ) , 1 , ( n-2p + 1 ) , n. The roots from AN are ( 2p + ) -1 , ( n-2p+ 1 ) , n. The iindices of the diagonal series are 2n-(4p+ ) and the algebraic sum of the roots is the one or the other , according as 1 is + or- ; but AM also passes to the series from1 R , and AN to the series from S , and go to R and S , and thus go up to W. AM also reaches the vertical line from M , and passes up to M , as AN does to N. Lastly , AM goes to N thus , and AN to W in a similar manner . Whatever be the Proc. Ror . Soc. Vo0i XVPl . Ill. D)iagram IN ? Il I___ _3579I 13 15 17 19 10on + 131 n]=is 01 165 173 185 201 221 2 273 305 341 35317 187 923 27 15 ; 41 1697'3 193 2 229 253 281 349 64 179 183 199 2 219 239 263 291 323 9715 17 29 X2|1 191 273 913 25 , 871 93 1 197 [ } < 1 217 2 253 277 305 337 9 373 691 55 17 I9 21 23 22 29 27 2 12 1 237 245 257 273 293 3+5 377 413 |41 | 23 1271 1283 2 99 3139 3 43 13 I 403 1439 161 94 25 301 313 29 349 1 373 401 3 469 1 19 21 253 25 2 29 31 33 35 37 18 21 231 227 2 > 347 3563 381 407 435 467 503 2 21 23 25 7 27 9 31 33 35 37 39 201 361 365 2 373 5 401 421 445 473 505 541 values of p and n , these connexions occur , but the form of them varies with the values of p and n. I have pointed out some of the results of having as the first term in the square an odd number of the form ( 4p + 2 ) , n+ 1 ; the forms will be 2n + 1 , Gn+1 , lOn+1 , 14n+1 , &c. , in which p may be 0 , 1 , 2 , 3 , &c. But there is another form which gives similar results , viz. 4pn + ( 2p + 1 ) , which is in many respects the " converse " of the other ; the forms will be 4n + 3 , 8n+5 , 12n+7 , 16n+9 , &c. These are the first terms to which this system gives rise . The ( n-p-1 ) th term is always Pp , p , n , n+ 1 . In the former system n produced the equal roots and p the uniequal ; here , p produces the equal and n the unequal roots , and 1 call the ( n-pI)th term A a & .n the other . This system has also W and M and N on each side of it , and other squares similar to the other , but the roots of which they are composed are differenitly formed . M and N come from below . W , instead of being -p+ 1 , -p , ,n-4p+2 , n , will be -3p , p , ( 'n-2p ) , ( i ? ? 1 -2p ) ) , and other terms are similarly altered , but the general result is the same . A specimen of a square of this form is given in Diagram No. 8 , but which canniot be reduced to the size of the Proceedings , where p=3 andn=16 ; the first number is 199 , and the square is completed so far as to show 5 , 13 , 1 , 2 that the roots of the 4 squiares whose sum is 19)9 , -3 , l , 10 1 , 10 ) , 7 , 7 but neither in this Diagram nor in Diagram No. 5 is the whole square completed ( to avoid confusion ) ; but if the series be traced in succession , the entire Diagram 6 would be filled up , and every term would disclose the roots whose squares compose it . In this mannier every odd number in all the series is divided into the squares that compose it ( not exceeding 4 ) , the squares being indicated by their roots . The two systems of ( 4p ? ? 2 ) xn +1 and 4 1.n ? +2p +1 include every possible odd numlber ; 4n +3 includes every alternate odd number from 3 ; 8n+5 every fourth number from 5 , and so on ; 2n ? +1 includes every odd number ; Gn ? ? 1 every third odd number . Many odd numbers belong to both systems , and to more than one in each . 15 1 is an examnple ; it is either 10(n +1 ( n-=15 ) , or it is 12n+ 7 ( n= 12 ) . The paper contains a Diagram ( No. 9 ) exhibiting the odd number 151 ) I as belonging to both systems ; but the Diagramn cannot be redu-ced . The roots of the squares that compose 151 are ( 10 . 1.5. . 5 ) , or ( 3 . 9 . 5 . 6 ) . i+.z E n ? Cs 0 F ; ~= 4wIo 0t12~~~~t cec~~~~~~~~~c 01_ 2 dF DX2X0 bnCD ? . ) H~~~ '1t ' Q 01 C. ) a cC.~~~~~~~~C n^tn Qq Fil t~~~~E cEI 4S : , a 01 _____ 0CI)S.~~~ ~~ 1 ? .~ -~ 4 ) I I~~~~~~~~~~~~)ht 0 r01~~~~~~~4 + 01 . 011 I U2~~~~~ '~~~gt Diagram No. 7 . There is an interval of n-3p +3 squares from the 1st term . *2n6P+4 *2n-6p Jr 4 p-+2 , pn 21)+ 2 , nX2p+ I __ 2 6+ 1 This Diagram ( No. 7 ) 2n-6l ) +4 -39+ 12 shows in terms of n and p the SX+ 1 , P-2p roots of X , S , an ( which ___ 2_____ _2p _ comes down diagonally from AN ) , T , and V , and the There is here an interval of number of squares between ( p-I ) squares from S to an . them ; the relative positions --______________ _ of these terms depend entirely 2n-4p +3 on p , and are always the + same for the same value of 2n 4.2 +2 _ , -p 2p P1 } an -_+_ , I Terms similar to these in n2p + 1 , n crease indefinitely as n increases . The value of cerThere is here an interval of taimi roots is independent of ( p-1 ) squiares from an to T. i , and therefore is the same -____________________ __ w Ufor every value of n. 2n-2p32 T p11 + I , p+l n-1 , 2n 2n-2p 2n-2p-1 v P,.r %pn , n+ 1
112600
3701662
Report on the Levelling from the Mediterranean to the Dead Sea
128
131
1,866
15
Proceedings of the Royal Society of London
Henry James
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0030
null
proceedings
1,860
1,850
1,800
4
170
2,094
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112600
10.1098/rspl.1866.0030
http://www.jstor.org/stable/112600
null
null
Geography
78.239383
Reporting
9.316885
Geography
[ 22.62889289855957, 38.22139358520508 ]
I. " Report on the Levelling from the Mediterranean to the Dead Sea . " By Colonel Sir HENRY JAMES , R.E. , F.R.S. Received April 5 , 1866 . The instructions for levelling from the Mediterranean to the Dead Sea having been received after the party had arrived at Jerusalem , it was thought best to level in the first place from Jerusalem to the Dead Sea during the cool months , and to complete the line to the Mediterranean at Jaffa , when the party were on their way home . But in describing the line levelled , we may assume that it was made direct from Jaffa to the Dead Sea . The line selected was that which runs across the maritime plain direct from Jaffa to Lydda , three miles beyond which , on the road to Beth Horon , the line turns to the right by Jimsu , Birfileeah , and Beit Sira ; and from thence up the Wady Suleiman to El Jib , where it again joins the old Roman Road from Lydda , by Beth Horon to Jerusalem . But at about 1 mile on the north road from the Damascus Gate , the line turns to the eastward over Mount Scopus , where it reached the altitude of 2724 feet , the height of the top of the large cairn on it . This was the highest point crossed between the Mediterranean and the Dead Sea . From Mount Scopus the line follows the high ground to the Mount of Olives , and thence takes the road down to Bethany , and , following the road by Khan Hladhur to near Jericho , the line turns to the right within about a mile of the latter place , and was carried thence across the plain bordering the Dead Sea to a point opposite a small island in the sea itself . [ May 3 , 128 Throughout the entire length of this line bench marks ( ) have been cut at intervals , wherever it was practicable , on the fixed rocks , or on permanent objects . The following is a list of the bench marks , with the distances between them : List of the Bench marks made in levelling the line from the Mediterranean to the Dead Sea in March , May , and June 1865 . No. Pla 'ce . Distance , in Miles and Links . Altitude . Where cut . Remarks . Jaffa ... ... ... ... ... ... 0 ... ... ... ... ... ... ... ... ... ... ... ... . , ... ... ... ... ... ... . Yazur ... ... ... ... ... . . Bethdagon ... ... ... ... Sephoneya ... ... ... ... ... ... ... ... . Lydda ... ... ... ... ... ... Lydda ... ... ... ... ... ... Jimzu ... ... ... ... ... ... , , ... ... ... ... ... ... , ) ... ... ... ... ... . . , , - ... ... ... ... ... ... , , ... ... ... ... ... .* , , ... ... ... ... ... ... , , ... ... ... ... ... . , ... . . ' ... ... ... ... , ... ... ... ... ... ... , ... ... ..o ... oo ... . , ... ... ... ... ... ... . . 00 1490 0 7972 1 5831 3 7656 5 5843 7 3157 9 6495 11 5922 14 0358 14 5194 15 1714 15 6495 16 4284 17 0548 18 0479 '18 7527 19 5196 21 7893 25 7849 26 5121 27 3392 30 3428 30 7617 33 5560 37 1670 feet 3-800 31-080 31-225 55-735 85-405 91-435 126-540 143-630 164-770 248-630 411-605 478-725 549-000 573-035 517-520 650-075 819-180 747-865 751-105 1,157-530 1,251-470 1,423-015 2,064-945 2,258-250 castle wall ... ... ... town wall ... ... ... on fountain ... ... on a well ... ... ... on a well ... ... ... on a well ... ... ... on a wall ... ... . . on a tree ... ... ... ... garden wall ... ... ... west angle of well. . on rock ... ... ... ... on rock ... ... ... ... on rock ... ... ... . on rock ... ... ... ... on rock ... ... ... ... on rock ... ... ... . . on rock ... ... ... ... on rock ... ... ... ... on rock ... ... ... ... on rock ... ... ... ... on rock ... ... ... ... on wall ... ... ... ... On rock ... ... ... ... on rock ... ... ... ... 2,419-505 on rock ... ... ... . . 2,681-915 on stone ... ... ... . . On the wall , 3800feet above level of the Mediterranean . On gate at entrance to town . On the fountain near Jaffa . At west side of road . At the east end of the village . At the west end of the village . In Sephoneya village , near lone tree . On a lone tree on maritime plain . At east end of Lydda village . Half a mile west of Jimzu village . In road at thrashingfloor , Jimzu . On side of road , top of hill . On road , top of hill . West side of road . Side of road , and junction of Wady . At junction of road to Birfilleya . East side of road . On side of road . In centre of road . On side of road . On side of road . Corner of garden wall in Wady . South side of stream . Entrance to Wady Suliemanl . East side of road . Near trigonometrical station , Jerusalem Survey . 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8 . 9 . 10 . 11 . 12 . 13 . 14 . 15 . 16 . 17 . 18 . 19 . 20 . 21 . 22 . 23 . 24 . 25 . 26 . TABLE ( continued ) . Distance , No. Place . in Miles Altitude . Where cut . Remarks . and Links ... ... -1_- ... ---^ , -I_ _ _ , ... ... ... ... ... ... . Mount Scopus ... ... . ? ... ... ..o ... . Mount Olivet ... ... Ascension ... ... ... ... Bethany ... ... ... ... ... 37 4078 37 6345 38 0612 38 1896 38 5086 38 6530 39 0236 39 1721 39 1731 39 2794 40 2409 ... ... ... ... ... 40 4225 ... ... ... ... ... 41 0148 Well of the Apostles. . Khan Hadhur ... ... , ... ... . Old Aqueduct , ... ... I ... ... . , ... ... . 41 6063 42 2457 43 1606 44 0032 45 0375 47 0498 47 3127 48 5296 50 2545 51 0706 52 7866 53 5174 54 0339 54 4465 ... ... 62 2514 feet 2,685-390 2,648-545 2,688-700 2,715-795 2,662-905 2,603-875 on stone ... ... ... . . on rock ... ... ... . . on cistern ... ... ... on rock ... ... ... ... on pillar ... ... ... ... on stone ... ... ... ... 2,623-790 on wall ... ... ... ... 2,662-500 on rock ... ... ... ... 2,665-080 surface ... ... ... ... ... 2,643-220 on house ... ... ... . . 2,281-825 on rock ... ... ... ... 2,208-755 on rock ... ... ... ... 2,018-350 1,519-615 1,351-845 1,163-060 1,039-145 902-515 654-190 776-130 870-590 537-010 451-510 89715 99'035 209 890 477-045 -1,273'215 ... ... 62 2965 -1,292-135 on rock ... ... ... ... on wall ... ... ... . . on rock ... ... ... . . on rock ... ... ... . . on rock ... ... ... ... on rock ... ... ... ... on stone ... ... ... ... on rock ... ... ... ... on rock ... ... ... ... on rock ... ... ... ... on rock ... ... ... ... on rock ... ... ... . on rock ... ... ... ... on rock ... ... ... . on rock ... ... ... ... on stone level of sea ... ... . . In centre of road . In centre of road . East side of road . Near G-ustam Pole . On east side of road . West side of road , near junction . West side of road . Near summit of Mount Olivet . At trigonometrical station . South side of road . Trigonometrical line , 13ethany to Scorpion . Near well , Bethany village . North side of road at junction of fences . Base of Bethany Hill . South side of road . South side of road . North side of road . Near junction of Nebi Musa . Opposite trees in valley . At the top of the hill . , At entrance to cave opposite Khan . On side of road . At top of hill . On side of road . On side of road . North side of road . In centre of road opposite house . Sunk on the beach of the Dead Sea opposite island . Height of Dead Sea on the 12th March , 1865 . At the distance of 3miles beyond Khan Hadhur , on the road to Jericho , the level of the Mediterranean was crossed , and from thence towards the Dead Sea the levels are marked with the negative sign . On the 12th of March , 1865 , the party reached the Dead Sea , when its level was found to be 1292 feet below the level of the Mediterranean- ; but from an examination of the drift wood on the shore , it was ascertained that at some time of the year , probably after the winter freshets , the water rises 2 } feet higher , which would make the least depression 1289'5 . 27 . 28 . 29 . 30 . 31 . 32 . 33 . 34 . 35 . 36 . 37 . 38 . 39 . 40 . 41 . 42 . 43 . 44 . 45 . 46 . 47 . 48 . 49 . 50 . 51 . 52 . 53 . 54 . 55 . From inquiry amongst the Bedouins and European residents in Palestine , it was ascertained that during the early summer the level of the sea falls at least 6 feet below the level at which it stood on the day the levelling was taken , which would make the depression 1298 feet ; and we may conclude that the maximum depression at no time exceeds 1300 feet . Lieut. Symonds , R.E. , in 1841 , made the depression 1312'2 feet . The soundings in the Dead Sea by Lieut. Vignes of the French Navy , gave a maximum depth of 1148 feet , making the depression of the bottom of the Dead Sea 2446 feet below the level of the Mediterranean . The soundings in the Mediterranean , midway between Malta and Candia , by Captain Spratt , R.N. , gave a depth of 13,020 feet , or a depression of the bottom five times greater than that of the bottom of the Dead Sea . The levelling was executed by two independent observers , and from a comparison of the two sets of levelling , it is certain that the levels have been obtained with absolute accuracy to within 3 or 4 inches . The establishment of a chain of levels across the country with bench marks cut on so many points , cannot but prove of the utmost importance for any future investigations , or for any more extended surveys in Palestine , such as are contemplated by the Society which has been formed since this survey was made , " for the accurate and systematic investigation of the archreology , the topography , the geology , and physical geography , &c. of the Holy Land , for Biblical illustration . " For the survey of Jerusalem itself , it was of the utmost importance , as it enabled us to connect all the levels in and about the city with the level of the Mediterranean , and to harmonize , so to speak , all the levels which have been taken .
112601
3701662
Note on the Amyl-Compounds Derived from Petroleum
131
132
1,866
15
Proceedings of the Royal Society of London
C. Schorlemmer
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0031
null
proceedings
1,860
1,850
1,800
2
38
407
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112601
10.1098/rspl.1866.0031
http://www.jstor.org/stable/112601
null
null
Chemistry 2
84.050095
Tables
8.330826
Chemistry
[ -34.44197463989258, -60.46554183959961 ]
II . " Note on the Amyl-Compounds derived from Petroleum . " By C. SCHORLEMMER . Communicated by Professor RoscoE . Received April 26 , 1866 . In a former communication I have shown that the hydride of heptyl obtained from petroleum has a higher specific gravity than its isomers ethyl-amyl , and hydride of heptyl from azelaic acid . The same is the case with their derivatives , and some of these isomeric compounds also show considerable differences in their boiling-points * . I could not compare the different heptyl-compounds which I prepared with those of heptyl-alcohol formed by fermentation , as the latter substance is very little known , and I therefore considered it interesting to compare the amylcompounds from fusel-oil with those obtained from petroleum . From the latter substance I prepared a considerable quantity of pure hydride of amyl , which boiled constantly at 33 ? -35 ? C. ; and I did not succeed in lowering the boiling-point any further . From this hydride other amylcompounds were obtained in exactly the same way as the heptyl-com* Proc. Roy . Soo . vol. xiv . p. 464 . 131 TOL . XV . pounds . Pure amyl-compounds from fusel-oil were also prepared with the greatest care , and their specific gravities and boiling-points compared , under exactly the same circumstances , with the compounds prepared from petroleum . The results of this investigation are contained in the following Table : Amyl-Compounds . Fromfusel oil . From pfetroleum . Boiling-point . Specific gravity . Boiling-point . Specific gravity . C5H12 ... 34 ? C. 0-6263 at 17 ? C IiTi CI 1010 C. 0-8750 at 20§ 101 ? C. 0-8777 at 20 ? Ct5Ho O0 140 ? C.* 08733 at 15§ 140 C. ? 0-8752 at 15 ? C , 12 O 132 ? C. 0 '8148 at 14§ 132 C. 0-8199 at 14 ? . It appears from this Table that the boiling-points of the same compounds agree perfectly , and that the specific gravities show only very small differences , those of the substances obtained from petroleum being a little higher . This is easily accounted for by an admixture of higher boiling compounds , which towards the end of the distillation raise the boilingpoints a little , and which cannot be removed completely , even by longcontinued rectifications . The amyl-compounds from petroleum and those from fusel-oil are therefore identical .
112602
3701662
On a New Series of Hydrocarbons Derived from Coal-Tar
132
136
1,866
15
Proceedings of the Royal Society of London
C. Schorlemmer
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0032
null
proceedings
1,860
1,850
1,800
5
108
1,751
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112602
10.1098/rspl.1866.0032
http://www.jstor.org/stable/112602
null
null
Chemistry 2
87.912842
Thermodynamics
10.422503
Chemistry
[ -35.17753982543945, -59.13991928100586 ]
III . " On a New Series of Hydrocarbons derived from Coal-tar . " By C. SCHORLEMMER . Communicated by Professor RoscoE . Received April 26 , 1866 . The light oils obtained by the destructive distillation of Cannel-coal at a low temperature , contain , besides the hydrocarbons of the marsh-gas and benzol series , other substances , which are attacked by concentrated sulphuric acid . If the oil , which has been repeatedly shaken with this acid , be subjected to distillation , the hydrocarbons which are unacted upon volatilize first , and a black tarry liquid , equal in bulk to about half the crude oil , remains behind t. On heating this residue more strongly , a brown oil , having an unpleasant smell , comes over at about 200 ? C. ; the temperature rises gradually up to 300 ? C. , and at last a black pitchy mass is left in the retort . Even after repeated rectifications the oil always leaves a solid black residue behind , and it was only by continued fractional distillations over solid caustic potash and metallic sodium , that I succeeded in isolating substances possessing nearly a constant boiling-point and volatilizing almost completely . The compounds which I thus obtained from Cannel-coal oil , boiling below 120 ? C. , are hydrocarbons of the general formula ( C , , H_2)2 , as the following analyses and determinations of the vapour-densities show:* ' The boiling-point of acetate of amyl is given very differently by different observers ( Cahours found 125 ? , Landolt 133-134 ? ; Pogg . Ann. vol. cxxii . p. 554 ) . M[y observation agrees perfectly with that of Wanklyn ( Chem. Soc. Journ. ( 2 . ) iii . p. 30 ) . t Journ. Chem. Soc. vol. xv . p. 420 . ( 1 ) C2 1H20 boiling-point 210 ? C. ( a ) 0'262 substance gave 0'840 carbonic acid and 0'290 water . ( b ) 0'1978 substance gave 0'635 carbonic acid and 0'2195 water . Calculated . Found . a-'-- , -b.a . C2 ... ... 144 87-8 87-44 87-55 H20 ... . 20 12'2 12*30 12*32 164 100'0 99*74 99'87 Globe with air ... ... ... 5'547 Temperature of air ... ... 17 ? C. Globe with vapour ... ... 5'730 Temperature on sealing. . 250 ? C. Capacity of globe . , ... . 65'0 cubic centims. Calculated . Found . 6*68 6'98 The residue in the globe had a brown colour , the oil not being completely volatile ; this accounts for the difference between the calculated and found vapour-densities . ( 2 ) C14 H2 , , , boiling-point 240 ? . 0'107 substance gave 0'343 carbonic acid and 0'1195 water . Calculated . Found . C14 . 168 875 87842 42 ... . 24 12'5 12-40 192 100'0 99'82 ( a ) Weight of globe ... ... . . 3.3354 Temperature of air ... ... 10 ? *5 C. Globe with vapour ... ... 3'5745 Temperature on sealing. . 280 ? C. Capacity of globe ... ... 676 cub. centims. ( b ) Weight of globe ... ... . . 3*286 Temperature of air ... ... 7 ? C. Globe with vapour ... ... 3*4665 Temperature on sealing. . 270 ? C. Capacity of globe ... ... 552 cub. centims. Found . Calculated . a. b. 6'65 70-6 7'02 The liquid remaining in the globe had also in both cases a brown colour . ( 3 ) C,1 H^8 , boiling-point 280 ? C. 0 152 substance gave 0'4885 carbonic acid and 0-174 water . Calculated . Found . C , , ... ... 192 87-27 87-11 H28 ... ... 28 12 73 12'72 220 100'00 99'83 N2 1866 . ] 133 These hydrocarbons are colourless , oily , strongly refracting liquids , lighter than water , and possessing a faint peculiar smell , resembling that of the roots of Daucus carota or Pastinaca sativa . I have obtained them in small quantities only , and could study their reactions therefore only incompletely . They combine with bromine with a hissing noise , and if the reaction is not moderated , the liquid blackens and hydrobromic acid is evolved ; but by keeping the substance well cooled , and by adding the bromine very carefully , nearly colourless , heavy , oily , sweet-smelling bromine-compounds are obtained , without the formation of hydrobromic acid . These are very easily decomposed by heating ; charry matter separates out , and hydrobromic acid is given off even below the boiling-point of water . From the hydrocarbon C 4H 2 alone I obtained a sufficient quantity of the bromide for analysis . 0'3715 substance gave 0 3605 bromide of silver and 0 0123 metallic silver . Calculated for Found . C14 H24 Br2 . 45'45 per cent. Br . 43'7 per cent. Br . As it was impossible to purify the small quantity of bromide , the difference between the found and calculated quantities is easily accounted for . Concentrated nitric acid dissolves these hydrocarbons , much heat being evolved ; on diluting the acid solution with water , yellow , heavy , thick oily nitro-compounds separate , which have a faint but peculiarly unpleasant smell . By heating these nitro-compounds with tin and hydrochloric acid , a portion is converted into a black tarry mass , and the solution contains a considerable quantity of chloride of ammonium , and a small quantity of a hydrochlorate , which can be obtained as a crystalline deliquescent mass by evaporating in vacuo . On concentrating the solution in the air , decomposition takes place , a violet substance being formed . By adding caustic potash to the solution of the hydrochlorate , a dark oily base separates , which quickly oxidizes into a black tarry mass . Platinic chloride produces at first no precipitate in the concentrated solution of the hydrochlorate , but after a few minutes a dark violet tar separates . I could not succeed in obtaining crystallized double chlorides of tin or zinc , If these hydrocarbons are heated with a concentrated solution of bichromate of potassium and sulphuric acid , carbonic acid is evolved , a strongly acid liquid , on which an oily layer swims , distils over , a resinous substance remaining in the retort . As I did not'obtain any of the pure hydrocarbons in sufficient quantity to study their separate products of oxidation , I took all that remained , together with the intermediate distillates , and the oil boiling above 280 ? C. , which had been previously well purified by rectification over sodium . After oxidation , the distillate was neutralized with carbonate of sodium , the oil being left undissolved . This neutral oil , which has an ethereal smell , and boils between 200 ? and 300 ? C. , gave on analysis 84'9 per cent. C and 11-8 per cent. I ; it consists , therefore , of non-oxidized hydrocarbons , containing a small quantity of an oxygencompound . The solution of the sodium-salt was evaporated on the waterbath , the residue distilled with diluterl sulphuric acid , and the distillate rectified . It smelt strongly of acetic acid , and also slightly of butyric acid . By neutralization with carbonate of sodium , a crop of crystals of acetate of sodium was obtained , which were converted into the crystallized silversalt . 0-1335 of this salt gave 0'861 of silver . Calculated for Found . C2 13 Ag 02 . 64'67 per cent. Ag . 64'50 per cent. Ag . The syrupy mother-liquor of the sodium-salt gave , with nitrate of silver , a white precipitate , which , on boiling the liquid , decomposed with effervescence and separation of metallic silver , showing the presence of formic acid ; from the filtered liquid small warty crystals of a silver-salt separated . 0'1314 of this salt gave 0'842 of silver , or 64'1 per cent. Ag . The mother-liquor gave on evaporation again crystals of acetate of silver . 0'2196 gave 0'1418 silver , or 64'56percent . The volatile acids produced by the oxidation of the hydrocarbons are therefore carbonic acid , acetic acid , formic acid , and perhaps a trace of an acid richer in carbon . The resinous substance left in the retort is an acid which dissolves in caustic potash , and is precipitated from this solution as a brown greasy substance , easily soluble in alcohol . The alcoholic solution , neutralized with ammonia , gave , with nitrate of silver , a white flocculent precipitate of a silver-salt , which dried into a brown resinous mass , not fit for analysis . As these hydrocarbons were obtained by the action of sulphuric acid on coal-tar oils boiling below 120 ? , and as they differ by C , H1 , it appears to me almost certain that they are polymers of the hydrocarbons of the acetylene series , C , H2 , -2 , formed in the same way as diamylene is formed , by treating amylene with sulphuric acid . The products of oxida . tion are also in accordance with this view . In order to test this theory , I have made some experiments with the two isomers C6 Ho1 , namely , diallyl and hexoylene . By acting with sulphuric acid on these compounds , I obtained , besides large quantities of tarry matter , polymeric modifications boiling above 200 ? , having a smell similar to the hydrocarbons described above , giving also similar nitro . compounds ; but the quantities which I got were not large enough for a more exact examination . The sulphuric acid which was used to purify the coal-tar oils contains an organic substance in solution , which can be isolated by neutralizing the acid liquid with carbonate of calcium , filtering , evaporating to dryness in the water-bath , extracting the residue with alcohol , and evaporating the alcoholic solution . It forms a yellow amorphous mass , which has a faint , bitter , and astringent taste . A substance with exactly the same properties was obtained from the acid which was used to act upon the hydrocarbons C Hl , . I am at present engaged upon experiments to isolate the hydrocarbons Cn H12n-2 contained in coal-tar .
112603
3701662
The Calculus of Chemical Operations; Being a Method for the Investigation, by Means of Symbols, of the Laws of the Distribution of Weight in Chemical Change. Part I.--On the Construction of Chemical Symbols. [Abstract]
136
139
1,866
15
Proceedings of the Royal Society of London
B. C. Brodie
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
4
67
1,469
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112603
null
http://www.jstor.org/stable/112603
null
null
Formulae
52.831516
Chemistry 2
32.439059
Mathematics
[ 22.489089965820312, -83.79106140136719 ]
IV . " The Calculus of Chemical Operations ; being a Method for the Investigation , by means of Symbols , of the Laws of the Distribution of Weight in Chemical Change . Part I.-On the Construction of Clhemical Symbols . " By Sir B. C. BRODIE , Bart. , F.R.S. , Professor of Chemistry in the UTniversity of Oxford . Received April 25 , 1866 . ( Abstract . ) In chemical transformations the absolute weight of matter is unialtered , and every chemical change , as regards weight , is a change in its arrangement and distribution . Now this distribution of weight is subject to numerical laws , and the object of the present method is to facilitate the study of these laws , by the aid of symbolic processes . The data of the chemical calculus , as indeed of every other application of symbols to the investigation of natural phenomenia , are supplied by observation and experiment ; and its aim is simply to deduce from these data the various consequences which may be inferred from them . The provinice of such a method commences where that of experiment terminates . This part comprises the consideration of the fundamental principles of symbolic expression in chemistry , and also the application of the method to the solution of perhaps the most importanit of all chemical problems , ramely ; the questioni of the true composition , as regards weight , of the units of chemical substances . Section I. In the first section certain definitions are given of those weights and relations of weight , of which the svmbols are subsequently considered . It may be regarded as containing an analysis of the subject of chemical investigation . The definitions are of " a chemical substance , " " a weight , " " a single weight , " " a group of weights , " " identical weights , " " a compound weight , " " a simple weight , " and " an integral compound weight . " The unit of a cheinical substalnce is defined as that weight of the substance which at 00 Centigrade , and 760 millims. pressure and in the condition of a perfect gas , occupies the volume of 1000 cubic centimetres . This volume is termed the unit of space . Section II . The second section treats of symbolic expression in chemistry . A " chemnical operation " is defined as an operation of which the result is a weight . These operationis are symbolized by letters , x , y , &c. An interpretation is assigned to the symbols + and - , as the symbols of aggregation and segregation , that is , of the mental operations by which groups are formed . The symbol _ is selected as the syinbol of cheemical identity ; the symbol 0 as the symbol of the absence of a weight , this symbol being identical with x-x . The symbol ( x+x ) is the symbol of two weights collectively considered , and as constituting a whole . The symbols xy and x are selected as the symbols of compound weights , yI and it is proved that with this interpretation these symbols are subject to the commutative and distributive laws , CCy=YXI x ( y + Y1)= xy + xy1 , and also to the index law , ^ , Pzq = zP+17 Section III . treats of the properties and interpretation of the chemical symbol 1 , which is selected as the symbol of the subject of chemical operations , namely , the unit of space . With this interpretationl the chemical symbol 1 has the property of the numerical symbol 1 given in the equation xl =X . Section IV . Chemical symbols are here shown to be subject to a special symbolic law , given in the equation xy=x+y . This property , by which chemical symnbols are distinguished from the symbols employed in other symbolic methods , is termed the " logarithmic " property of these symibols . A consequence of this property is that 0=1 , and that any number of numerical symbols may be added to a chemical function without affecting its interpretation as regards weight . Section V. relates to the special properties of the symbols of simple weights , which are termed prime factors , from their analogy to the priime factors of numbers . These symbols differ , however , from these factors in that , like the numerical symbol 1 , they are incapable of partitioni as well as of division , which is a consequence of the condition xy=x+y . The symbol of the unit of a chemical substance , expressed as a function of the simple weights of which it consists , is identical with the.symbol of a whole riumber expressed by means of its prime factor , a " , V , 1"2 ... . A general method is given for discovering the prime factors of chernical symbols . Section VI . is on the construction of chemical equations from experimental data . Section VII . On the expression of chemical symbols by means of prime factors in the actual system of chemical equations . The object of this section is to prove that the units of weight of chemical substanices are integral compound weights , and to discover the simplest expression for the symbols which is consistent with this assumptioni . Such an expression cannot be effected unless some one symbol be determined from external considerations . The unit of hydrogen , therefore , is assumed to consist of one simple weight , its symbol being expressed by one prime factor , a , which is termed the viodulus of the symbolic system . This assertion is the expression of a hypothesis which may be proved or disproved by facts , and the consequences of which are here traced . The symbols of the elements are considered in three groups . 1 . The symbols of the elements of which the density in the gaseous conditionl can be experimentally determined , and which form with one another gaseous combinations . 2 . The symbols of carbon , boron , and silicon . 3 . The symbols of other elements , which are determined with a certain probability by the aid of the law of Dulong . For the method of constructing these symbols , which depends upon the solution in whole numbers of certain simple indeterminate equations , we must refer to the memoir itself . The following symbols may serve as an illustration of the general results : Absolute Relative Name of substance . Prime factor . weight in weight . grammes . a 0-089 1 0-715 8x1 542 17 25 v 0-581 65 ci 1-805 15 0-536 6 Symbol . Hydrogen ... ... ... ... a0 089 1 Oxygen ... ... ... ... 42 1.430 16 Water ... ... ... ... a 0 804 9 Chlorine . , ... ... ... . aX2 3-173 35-5 Hydrochloric acid ... ... ... ... aX 1-631 18-25 Oxide of chlorinie ... * X ... ax2Z 3-888 43 5 Hypochlorous acid ... ... ... ax 3 2-346 26-25 Teroxide of chlorine ... ax 21 5 319 59 5 Chlorous acid ... ... ... ... ... ax 23 062 34 25 Chloric acid ... ... ... ... aX 3 3-777 42-25 Nitrogen ... ... ... ... ... ... av2 1251 14 Ammonia ... ... ... ... ... . a2v 0 760 85 Protoxide of nitrogen ... ... ... ... av24 1966 22 Nitrite of ammoniun ... ... a3v2V2 2-860 32 Chloride of ammoniumn ... ... ... . . ca3vx 2 391 26-75 Phosphorus ... ... . . a4 5-541 62 Phosphide of hydrogen ... ... ... a 2o 1*519 17 Pentachloride of phosphorus ... ... . a 35 9 319 104-25 Tercbloride of phosphorus ... ... a20X3 6-145 68-75 Oxychloride of phosphorus ... ... a 6-869 76-75 Carbon ... ... ... ... ... ... . ICY 0-536+y 6+y Acetylene ... ... ... ... alc 1 161 13 Marsh-gas. . a2I 0 704 8 Alcohol ... ... ... ... a 2-056 23 Ether ... ... ... ... ... a r ' 3 308 37 Acetic anhydride ... ... . a32K22 4-559 51 Acetic acid ... ... 2C2 20682 30 Trichloracetic acid ... ... . a2%3gC2t2 6-146 68-75 Hydrocyanic acid ... ... ... ... avrc 1 207 13-5 Cyanogcn ... ... . av2x2 2-324 26 Section VIII . Certain apparent exceptions are considered , in which it is not found possible to express the symbols of chemical substances by means of an integral number of prime factors , consistently with the assumption of the modulus a.
112604
3701662
On the Motion of a Rigid Body Moving Freely about a Fixed Point. [Abstract]
139
144
1,866
15
Proceedings of the Royal Society of London
J. J. Sylvester
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
6
46
2,803
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112604
null
http://www.jstor.org/stable/112604
null
null
Fluid Dynamics
58.571742
Formulae
21.45455
Fluid Dynamics
[ 56.14847183227539, -31.226396560668945 ]
I. " 'On the Motion of a Rigid Body moving freely about a Fixed Point . " By J. J. SYLVESTER , LL. D. , F.R.S. Received April 26 , 1866 . ( Abstract . ) The nature of the present brief memoir will be best conveyed by my giving a succinct account of the principal results which it embodies , in the order in which they occur . The direct soluition , in its present form , of the important problem of the motion of a rigid body acted on by no external forces , originating in the admirable labours of Euler , has received the last degree of finish and completeness of which it is susceptible from the powerful analysis of Jacobi ; in one sense , therefore , it may be said that the discussion is closed and the question at an end . Notwithstanding this , in the mode of conceiving and representing the general character of the motion , there are certain circumstances which merit attention , and which may be expressed without reference to the formulw in which the analytical solution is contained . Poinsot 's method of representing the motion by means of his so-called " central ellipsoid " has passed into the every-day language of geometers , and may be assumed to be familiar to all . The centre of this ellipsoid is supposed to be stationary at the point rounid which any given solid body is turning ; its form is determined when the principal moments of inertia of that body are given , and it is suipposed accurately to roll without sliding on a fixed plane whose position depends on the initial circumstances of the motion . The associated free body is conceived as being carried along by the ellipsoid , so that its path in space , its continuous succession of changes of position , is thereby completely represented ; but no image is thus presented to the mind of the time in which the change of position is effected . I show how this defect in the representation may be remedied , and the time , like the law of displacement , reduced to observation by a slight modification of the apparatus of the central ellipsoid or representative nucleus , as it will for the moment be more convenient to call it . To steady the ideas , imagine the fixed invariable plane of contact with the nucleus to be horizontal and situated under it ; nOw colnceive a portion of its upper surface , say the upper half , to be pared away until it assumes the form of a semiellipsoid confocal to the original surface , and that an indefinitely rough plate always remaining horizontal , bIut capable of turning in its own plane round a vertical axis , which , if produced , would pass through the centre of the ellipsoid , is placed in contact with this upper portion ; as the nucleus is made to roll with the under part of its surface upon the fixed plane below , the friction between the upper surface and the plate will cause the latter to rotate round its axis , for the niucleus will not oinly roll upon the plate above , but at the same time have a swilnging mnotion roulnd the vertical , which will be communicated to the plate . I prove , by an easy application of the theory of confocal ellipsoids , that the time of the free body passing from one position to another will be in a constaint ratio to this miotion of rotation , which may be measured off upon an absolutely fixed dial face immediately over the rotating-plate ; and furthermore I show that the relationi between the angular divisions of this dial and the timiie depends only upon the spinnilg force which may be supposed to set the free body originially in motion , so that it will hold the same , at whatever distance , by a preliminary adjustment , the rotating-plate may be supposed to be set fromii the fixed horizontal plane . Thus , then , we may realize a complete kinematical image of all the circumstances of the motion of a free rotating body , and reduce to a purely mechanical measurement the determination of an element hitherto unrepresented , but in reality the most important of all , viz. the time . I then proceed to point out a very singular and hitherto unnoticed dynamicazl relation between the free rotating body and the ellipsoidal top , as I shall now prefer to call Poinsot 's central ellipsoid , because I imagine it set spinning like a top upon the invariable plane in contact with it and left to roll of its own accord , the friction between it and the plane being supposed adequate to prevenlt all sliding . I start with supposing that the density of the top follows any law whatever , and call its principal moniciits of inertia A , B , C , its semiaxes a , 6 , c , the relationis betweeni these six quantities being left arbitrary . It is easy to establish that , if a rotating body be acted oln by any forces which always meet the axis about which it is at any instant turning , the vis viva will remain unaffected by their action ; this will be the case in the present instance with the pressure and friction of the invariable plane , the only forces concerned , as we may either leave gravity out of account altogether or suppose the cenitre of gravity of the top to be at the centre of the ellipsoid , which will come to the same thing . By aid of this principle , conjoined with the two conditions to which the angular velocities of the associated free body are known to be subject , it is easy to infer that the velocities of this body and its representative top will , throughout the motion , remain in a constant ratio , or , if we please , equal to one another , provided that AllXIaa 612 b c4 : where X is an arbitrary constant . If , now , we revert to the natural supposition of the top beirig of uniform denlsity , it is well known that A : B : C : : b2+c2 : c2+a'2 : a'+ b2 and these ratios may be identified with those above ( although this would not at the first blush be supposed to be the case ) by giving a suitable value to the arbitrary constant X. Thus , then , Poinsot 's central ellipsoid supposed of uniform density and set spinning upon a roughened inivariable plane will represenit the motion of a free rotating solid , not in space only but also in time ; the body and the top may be conceived as continually moving round the same axis and at the same rate at each moment of time * . The problem of the top is completed in the memoir by applying the general Eulerian equations to determine the friction and pressure , a process which involves some rather operose but successfully executed algebraical calculations . I next proceed to account analytically for the kinematical theory established at the outset of the memoir , and in . doing so am necessarily led to give greater completeness to it , and at the same time an extension to the existing theory of confocal surfaces of the second order , by introducing the complementary motion of surfaces that I call contrafocal to one another : confocal ellipsoids are those the differences between the squiares of whose corresponding principal arcs are all three the same ; contrafocal ellipsoids I define to be those the sums of the squares of whose corresponding arcs are the same . Any two bodies whose central ellipsoids are either confocal or contrafocal I term related-correlated in the onie case , contrarelated in the other , and I show that the kinematical construction in question is only another renidering of the first of the propositions hereini subjoined concerning bodies so related . 1st . If two correlated bodies be placed with their principal axes respectively parallel and be set spinning by the same impulsive couple , they will move so that the corresponding axes of the one and the other body will continue always equally inclined to the axis of the couple , and their original parallelism at any instant may be restored by turnling one of the bodies about this last-named axis through an angle proportional to the time elapsed since the commencement of the motion . Virtually , this amounts to saying that the difference between the displacement of two correlated bodies subject to the same initial impulse is equivalent to a simple uniform motion about the invariable line . 2nd . So , in like manner , if the bodies be contrarelated , the sum of their displacements is equivalent to a simple uinifornm motion about such line . 3rd . In either case alike , the difference between the squared angular velocities of the related bodies is constant throughout the motion . From these propositions it follows that for all practical intents and purposes the motion of any body is sufficiently represented by the motion of any other one correlated or contrarelated to it . To a spectator on the invariable plane the apparent motion of one rotating body may be made identical with that of any other related one by merely making the plane on which he stands turn uniformly round a perpendicular axis . It becomes natural , then , to ascertain whether there is not always some one or more simplest form or forms which may be selected out of the whole couple of infiinite series of related bodies , which may conveniently be adopted as the exemplar or type of all the rest . Obviously , the best suited for such purpose will be a body reduced to only two dimensions , in other words an indefinitely flattened disk , provided that it be possible in all cases to find a disk cor related or contrarelated to any given solid* . The algebraical investigation for ascertaining the existence of such disk is the same whichever species of relationl is made the subject of inquiry , and leads to the construction of three quadratic equations corresponiding to the respective suppositions of the original body becoming indefinitely flattened in the direction of each of its three principal axes in turn ; so that for a moment it might be supposed that the number of disks fulfilling the required condition could , according to circumstances , be zero , two , four , or six . But on closer examination , and bearing in mind that niegative equally with imaginary moments of inertia are inadmissible , it turns out that there are always two such disks , and no more ( except in the case of two of the moments of inertia being equal when the solution becomes unique ) . Of these two disks , one will be correlated and the other contrarelated to the given body , and they will be respectively perpendicular to the axes of greatest and least moments of inertia . We have thus the choice between two methods of reduction to the type form , and this choice is not a matter of unimportance ( in nature nothing exists in vain ) ; for by means tbereof the motion of any given body subject to any initial conditions can be made to depend upon either at will of the two comprehensive cases ( Legendre 's 1st and 3rd ) to which the motion of a free rotating body is usually referred , so that the distinction between these two cases ( corresponding to the two species of Polhodes on either side of the " Dividing Polhode , " according to Poinsot 's method of exposition ) is virtuially abrogated . From the preceding theory , it follows ( as also may be made to appear alike from an attentive synoptic view of the commonly received analytical formulae as from Poinsot 's theory of the associated " sliding and rolling cone " ) that in the problem of the motion of a free body , of whatever form and subject to whatever initial conditions one pleases , there enter but two arbitrary parameters . Calling A , B , A+ B the three moments of inertia of one or the other equivalent disks , L the magnitude of the impulsive couple , M the vis viva , these two parameters ( say p , q ) will be AL , BL ' ; if to them we add a quantity Mt t say r ( where t is the terms reckoned , as it may be , from an intrinsic epoch as explained in the memoir ) , all other elements of the motion , as the total or partial velocities and the angles , whatever they may be , selected to determine the position of the rotating body become known functions of these three quantities , p , q , r , and may be reduced to tables of triple entry , or be graphically represented by a few charts of cuirves ; and it should be noticed that p , the smaller of the two parameters p , q , will be always necessarily included between o and 1 , and that the other parameter q may , by a due choice of the species of reduction adopted , beforcibly retained within the same limits . The five quantities o , p , q , 1 , p+q will then form an ascending series of magnitudes subject only to the liability of the middle term q to become equal to 1 on the one hand , or to p on the other : q becoming unity corresponds to the case of the so-called " Dividing Polhode , " Legendre 's 2nd case ( " cas tre 's remarquabte " ) ; and q becoming equal to p is of course the case of the body itself , or its " central ellipsoid , " becoming a figure of revolution , in which case the motion is practically the same as that of a uniform circular plate . Besides these two exceptional cases , the only singular cases properly so called , the quinary scale of magnitudes just exhibited serves to indicate all the more remarkable cases ( requiring or inviting particular methods of treatment ) which can present themselves in the theory . These may be distinguished into special cases , which arise from any two consecutive terms becoming ( to use Prof. De Morgan 's expressive term ) subequal , i. e. differing from one another by a quantity whose square may be neglected , and double special cases , which arise when any three consecutive terms become subequal ; all of which , together with peculiar subcases appertaininJg to the double special class , perhaps deserve more thorough examination than may have been hitherto accorded to them . I conclude the memoir with pointing out the place which this problem of Rotation appears to me to occupy in dynamical theory , as belonging to a natural and perfectly well defined group of questions , of which the motion of a body attracted to two fixed centres and the renownied problem of three bodies acted on by their mutual attractions are conspicuous instances . This group is characterized by the feature that , as regards them , equations of motion admit of being conistructed , from which not only the element of time , as in ordiniary mechanical problems , but also an element of absoluite space is shut out ; supposing the equations thus reduced by two in the number of the variables to have been integrated , Jacobi 's theory of the last multiplier serves to reduce both the excluded elements to quadratures and thus to complete the solution . I notice that whilst the time may fairly be said to be eliminated , the space element may be more properly said to undergo the negative process , if it may be so called , of ab-limination ; it is not introduced into and then expelled from , but prevented from ever making its appearance at all in the resolving system of differential equations . It is from the study of one of these allied but more difficult questions that the present memoir has taken its rise as a collateral inquiry and elucidatory digression .
112605
3701662
On Appold's Apparatus for Regulating Temperature and Keeping the Air in a Building at Any Desired Degree of Moisture
144
146
1,866
15
Proceedings of the Royal Society of London
J. P. Gassiot
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0035
null
proceedings
1,860
1,850
1,800
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1,122
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112605
10.1098/rspl.1866.0035
http://www.jstor.org/stable/112605
null
null
Measurement
35.049634
Thermodynamics
32.228144
Measurement
[ 24.15070152282715, 12.31998348236084 ]
II . " On Appold 's Apparatus for regulating Temperature and keeping the Air in a Building at any desired degree of Moisture . " By J.P. GASSIOT , Esq. , V.P.R.S. Received May 3 , 1866 . Those Fellows of the Royal Society who were acquainted with the late Mr. John George Appold , have often expressed their admiration at the various scientific arrangements which he from time to time adapted to his dwellinghouse in Wilson Street , Finsbury Square . However intense might be the frost of winter or the heat of summer , or the brilliancy of the gas with which his rooms were lighted , when once under his hospitable roof you enjoyed a pure and refreshing atmosphere . Much of this was undoubtedly due to the steam-power he always had at command connected with his business premises immediately adjacent to his dwelling-house , by which he could at any time force a current of fresh air at a given temperature into any of his rooms ; indeed Mr. Appold always contended that houses could not be made thoroughly comfortable as habitations without the aid of steam-power . But among the many of his arrangements to obtain equable temperature in rooms , there were also those that do not require the aid of steam-power , so seldom applicable in private dwellings , and which , being easy of adaptation , might be used in private houses with much advantage as regards the health and comfort of the inmates . I allude to his Automatic Temperature regulator , and to his Automatic Hygrometer ; and these instruments , as originally constructed by her late husband , and used for many years in their house , but now repaired and placed in perfect working order by Mr. Browning , Mrs. Appold has requested me to offer in her name to the President and Council of the Royal Society . She desires me to express a hope that they will oblige her by retaining them among the other scientific apparatus belonging to the Royal Society , as a mark of respect to the memory of one who always highly esteemed the honour he received when he was elected into that body in June 1853 . I annex a description and drawing of both instruments ( Plate VII ) . Appold 's apparatus for regulating the temperature of buildings automatically . This instrument consists of a glass tube having bulbs at each end . The 144 [ May 17 , tube is filled , as also about half of each bulb , with mercury ; the lower bulb containing ether to the depth of half an inch , which floats on the mercury . The tube is secured to a plate of boxwood , and supported on knife-edges , on which it turns freely . At the end of the plate , underneath the highest bulb , is a lever , to which a string is attached . This string is carried , by means of bell-cranks , to the supply-valve of a gas-stove , or the damper of a furnace . The instrument acts in the following manner:-Supposing the stove to be lighted and to have raised the temperature more than is required , the heat will convert a portion of the ether in the lower bulb into vapour . The expansion of this vapour drives a quantity of the mercury out of the bulb underneath it through the tube into the upper bulb . The end to which the mercury has been driven being thus rendered the heaviest falls , and motion being communicated by the lever to the string , this closes the supply-valve or damper of the stove or furnace . Of course , if this should be carried beyond the required extent the reverse action will take place . A weight in the centre of the plate , the position of which is regulated by a milled-head screw shown at the side , serves to alter the centre of gravity of the whole apparatus . The value of the motion of this weight being carefully ascertained , a scale is engraved upon it . By moving this weight , according to a scale engraved on it , the instrument may be set so as to maintain any desired temperature in the building in which it is fixed . The range of action of the instrument is from 54 ? to 66 ? Fahr. , and with a change of temperature of one degree it has the power to raise one ounce three inches . Appolds automatic Hygrometerfor keeping the Air in a Building at any desired degree of moisture . This instrument , both in principle and construction , is very similar to the automatic regulator just described . The acting portion consists also of a tube with a bulb at each end . This tube contains mercury to about half the height of each bulb , and a portion of ether floating on the mercury at each end . One half of the tube and one bulb is covered with bibulous paper , which is always kept wet , and the tube is suspended and turns freely on knife-edges placed just above the covered bulb . The action of the apparatus is as follows : A deficiency of moisture in the air increases the evaporation from the bibulous paper . This evaporation produces cold , which condenses the vapour of the ether in the covered bulb , and the mercury being pressed on by the vapour of the ether in the naked bulb is forced into the covered bulb . The uncovered bulb , being now much the lightest , rises , and raises a lever , which in its turn opens a valve at the end of a small tube . This tube communicates with a cistern kept full of water . The water which is thus admitted is suffered to trickle over heated pipes which are covered 1866 . ] 145 with bibulous paper ; upon the desired dew-point being attained , the action ceases . The range of the instrument is regulated by means of a spiral spring at one end of the tube , and an adjustable weight at the other . By means of a pencil attached to one of the levers , the instrument may be made self-registering . An ordinary Mason 's hygrometer is attached to the instrument for regulation and comparison . With a variation of one degree in the moisture of the atmosphere , the instrument is capable of supplying ten quarts of water per hour to the surface of the pipes from which it evaporated .
112606
3701662
On the Spectrum of a New Star in Corona Borealis
146
149
1,866
15
Proceedings of the Royal Society of London
William Huggins|W. A. Miller
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0036
null
proceedings
1,860
1,850
1,800
4
68
1,961
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112606
10.1098/rspl.1866.0036
http://www.jstor.org/stable/112606
null
null
Atomic Physics
47.616369
Astronomy
31.699267
Atomic Physics
[ 84.8935546875, 17.863435745239258 ]
III . " On the Spectrum of a New Star in Corona Borealis " - . By WILLIAM HUGGINS , F.R.S. , and W. A. MILLER , M.D. , Treas . R.S. Received May 17 , 1866 . Yesterday , May the 16th , one of us received a note from Mr. John Birmingham of Tuam , stating that he had observed on the night of May 12 a new star in the constellation of Corona Borealis . he describes the star as " very brilliant , of about the 2nd magnitude . " Also Mr. Baxendell of Manchester wrote to one of us giving the observations which follow of the new star , as seen by him on the night of the 15th instant . " A new star has suddenly burst forth in Corona . It is somewhat less than a degree distant from e of that constellation in a south-easterly direction , and last night was fully equal in brilliancy to f3 Serpentis or v HIerculis , both stars of about the 3rd magnitude . " Last night , May 16 , we observed this remarkable object . The star appeared to us considerably below the 3rd magnitude , but brighter than e Coronae . In the telescope it was surrounded with a faint nebulous haze , extending to a considerable distance , and gradually fading away at the boundaryt . A comparative examination of neighbouring stars showed * The Astronomer Royal wrote to one of us on the 18th , " Last night we got a meridian observation of it ; on a rough reduction its elements areR . A. 1866 , May 17 ... ... ... ... ... ... ... ... 15h 53m 569s08 , N.P.D ... ... ... ... ... ... ... ... ... ... ... ... ... 63§ 41 ' 53 " , agreeing precisely with Argelander , No. 2765 of " Bonner Sternverzeichniss , " declination + 26 ? , magnitude 9'5 . " Mr. ]Baxendell writes on the 21st , " It is probable that this star will turn out to be a variable of long or irregular period , and it may be conveniently at once designated T Coronae . " Sir John Ilerschel informs one of us that on June 9 , 1842 , he saw a star of the 6th magnitude in Corona very nearly in the place of this strange star . As Sir John Herschel 's position was laid down merely by naked eye allineations , the star seen by him may have been possibly a former temporary outburst of light in this remarkable object . t On the 17th this nebulosity was suspected only ; on the 19th and 21st it was not seen . that this nebulosity really existed about the star . When the spectroscope was placed on the telescope , the light of this new star formed a spectrum unlike that of any celestial body which we have hitherto examined . The light of the star is compound , and has emanated from two different sources . Each light forms its own spectrum . In the instrument these spectra appear superposed . The principal spectrum is analogous to that of the sun , and is evidently formed by the light of an incandescent solid or liquid photosphere , which has suffered absorption by the vapours of an envelope cooler than itself . The second spectrum consists of a few bright lines , which indicate that the light by which it is formed was emitted by matter in the state of luminous gas . These spectra are represented with considerable approximative accuracy in a diagram which accompanies this paper . Spectrulim of Absorption and Spectrum of Bright Lines forming the Compound Spectrum of a New Star near e Coronae Borealis . Description of the spectrum of absorption . In the red a little more refrangible than Fraunhofer 's C are two strong dark lines . The interval between these and a line a little less refrangible than D is shaded by a number of fine lines very near each other . A less strongly marked line is seen about the place of solar D. Between D and a portion of the spectrum about the place of b of the solar spectrum , the lines of absorption are numerous , but very thin and faint . A little beyond b commences a series of close groups of strong lines ; these follow each other at small intervals , as far as the spectrum can be traced . Description of the gaseous spectrum.-A bright line , much more brilliant than the part of the continuous spectrum upon which it falls , occupies a position which several measures make to be coincident with Fraunhofer 's F t. At rather more than one-fourth of the distance which * The position of the groups of dark lines shows that the light of the photosphere , after passing through the absorbent atmosphere , is yellow . The light , however , of the green and blue bright lines makes up to some extent for the green and blue rays ( of other refrangibilities ) which have been stopped by absorption . To the eye , therefore , the star appears nearly white . However , as the star flickers , there may be noticed an occasional preponderance of yellow or blue . Mr. Baxendell , without knowing the results of prismatic analysis , describes the impression he received to be " as if the yellow of the star were seen through an overlying film of a blue tint . " t On the 17th , the lines of hydrogen , produced by taking the induction-spark through the vapour of water , were compared in the instrument simultaneously with the bright ines of the star . The brightest line coincided with the middle of the expanded line of hydrogen which corresponds to Fraunhofer 's F. On account of the faintness of the red separates F from G , a second and less brilliant line was seen . Both these lines were narrow and sharply defined . Beyond these lines , and at a distance a little more than one-third of that which separates the second bright line from the strongest bright one , a third bright line was observed . The appearance of this line suggested that it was either double or undefined at the edges . In the more refrangible part of the spectrum , probably not far from G of the solar spectrum , glimpses were obtained of a fourth and faint bright line . At the extreme end of the visible part of the less refrangible end of the spectrum , about C , appeared a line brighter than the normal relative brilliancy of this part of the spectrum . The brightness of this line , however , was not nearly so marked in proportion to that of the part of the spectrum where it occurs , as was that of the lines in the green and blue . General Conclusions.-It is difficult to imagine the present physical constitution of this remarkable object . There must be a photosphere of matter in the solid or liquid state emitting light of all refrangibilities . Surrounding this must exist also an atmosphere of cooler vapours , which give rise by absorption to the groups of dark lines . Besides this constitution , which it possesses in common with the sun and the stars , there must exist the source of the gaseous spectrum . That this is not produced by the faint nebulosity seen about the star is evident by the brightness of the lines , and the circumstance that they do not extend in the instrument beyond the boundaries of the continuous spectrum . The gaseous mass from which this light emanates must be at a much higher temperature than the photosphere of the star ; otherwise it would appear impossible to explain the great brilliancy of the lines compared with the corresponding parts of the continuous spectrum of the photosphere . The position of two of the bright lines suggests that this gas may consist chiefly of hydrogen . If , however , hydrogen be really the source of some of the bright lines , the conditions under which the gas emits the light must be different from those to which it has been submitted in terrestrial observations ; for it is well known that the line of hydrogen in the green is always fainter and more expanded than the brilliant red line which characterizes the spectrum of this gas . On the other hand , the strong absorption indicated by the end of the spectrum , when the amount of dispersion necessary for these observations wa:s employed , the exact coincidence of the line in this part of the spectrum with the red line of hydrogen , though extremely probable , was not determined with equal certainty . * The spectra of the star were observed again on the 17th , the 19th , the 21st , and the 23rd . On these evenings no important alteration had taken place . On the 17th and succeeding evenings , though the spectrum of the waning star was fainter than on the 16th , the red bright line appeared a little brighter relatively to the green and blue bright lines . On the 19th and 21st the absorption lines about b were stronger than on the 16th . From the 16th the continuous spectrum diminished in brightness more rapidly than the gaseous spectrum , so that on the 23rd , though the spectrum as a whole was faint , the bright lines were brilliant when compared with the continuous spectrum . 148 line F of the solar spectrum , and the still stronger corresponding lines in some stars , would indicate that under suitable conditions hydrogen may emit a strong luminous radiation of this refrangibility* . The character of the spectrum of this star , taken together with its sudden outburst in brilliancy and its rapid decline in brightness , suggest to us the rather bold speculation that , in consequence of some vast convulsion taking place in this object , large quantities of gas have been evolved from it , that the hydrogen present is burning by combination with some other element and furnishes the light represented by the bright lines , also that the flaming gas has heated to vivid incandescence the solid matter of the photosphere . As the hydrogen becomes exhausted , all the phenomena diminish in intensity , and the star rapidly wanes . In connexion with this star , the observations which we made upon the spectra of a Orionis and / f Pegasi , that they contain no absorption lines of hydrogen , appear to have some new interest . The spectra of these stars agree in their general characters with the absorption spectrum of the new star . The whole class of white stars are distinguished by having hydrogen lines of extraordinary force . It may also be mentioned here that we have found that the spectra of several of the more remarkable of the variable stars , namely those distinguished by an orange or ruddy tint , possess a close general accordance with those of a Orionis , 3 Pegasi , and the absorption spectrum of the remarkable object described in this paper . The purely speculative idea presents itself from these observations , that hydrogen probably plays an important part in the differences of physical constitution which apparently separate the stars into groups , and possibly also in the changes by which these differences may be brought aboutt .
112607
3701662
Condensation of Determinants, Being a New and Brief Method for Computing their Arithmetical Values
150
155
1,866
15
Proceedings of the Royal Society of London
C. L. Dodgson
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0037
null
proceedings
1,860
1,850
1,800
6
52
2,025
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112607
10.1098/rspl.1866.0037
http://www.jstor.org/stable/112607
null
null
Formulae
64.329115
Measurement
20.714189
Mathematics
[ 75.05424499511719, -31.093351364135742 ]
IV . " Condensation of Determinants , being a new and brief Method for computing their arithmetical values . " By the Rev. C. L. DODGSON , M.A. , Student of Christ Church , Oxford . Communicated by the Rev. BARTHOLOMEW PuICE , M.A. , F.R.S. Received May 15 , 1866 . If it be proposed to solve a set of n simultaneous linear equations , not being all homogeneous , involving n unknowns , or to test their compatibility when all are homogeneous , by the method of determinants , in these , as well as in other cases of common occurrence , it is necessary to compute the arithmetical values of one or more determinants-such , for example , as 1 , 3 , -2 2,1 , 4 3 , 5,1 Now the only method , so far as I am aware , that has been hitherto employed for such a purpose , is that of multiplying each term of the first row or column by the determinant of its complemental minor , and affecting the products with the signs + and alternately , the determinants required in the process being , in their turn , broken up in the same manner until determinants are finally arrived at sufficiently small for mental computation . This process , in the above instance , would run thus:1 , 3 , --2 2,1 , 4 =1x 14 -2x 3--2 +3X -312 3:~5 , -1 5 , -1 5 , --11 1 , 4 3 , 5 , --1 i =-21-14+42=7 . But such a process , when the block consists of 16 , 25 , or more terms , is so tedious that the old method of elimination is much to be preferred for solving simultaneous equations ; so that the new method , excepting for equations containing 2 or 3 unknowns , is practically useless . The new method of computation , which I now proceed to explain , and for which " Condensation " appears to be an appropriate name , will be found , I believe , to be far shorter and simpler than any hitherto employed . In the following remarks I shall use the word " Block " to denote any number of terms arranged in rows and columns , and " interior of a block " to denote the block which remains when the first and last rows and columns are erased . The process of " Condensation " is exhibited in the following rules , in which the given block is supposed to consist of n rows and n columns:(1 ) Arrange the given block , if necessary , so that no ciphers occur in its interior . This may be done either by transposing rows or columns , or by adding to certain rows the several terms of other rows multiplied by certain multipliers . ( 2 ) Compute the determinant of every minor consisting of four adjacent terms . These values will constitute a second block , consisting of n-rows and n-1 columns . ( 3 ) Condense this second block in the same manner , dividing each term , when found , by the corresponding term in the interior of the first block . ( 4 ) Repeat this process as often as may be necessary ( observing that in condensing any block of the series , the rth for example , the terms so found must be divided by the corresponding terms in the interior of the r--lth block ) , until the block is condensed to a single term , which will be the required value . As an instance of the foregoing rules , let us take the block -2 -1 -1 -4 -1 -2 -1 -6 -1 -1 2421 -3 -8 3 -1 2 By rule ( 2 ) this is condensed into --1 -5 8 ; this , again , by 11 -4 rule ( 3 ) , is condensed into I --26 and this , by rule ( 4 ) , into -8 , which is the required value . The simplest method of working this rule appears to be to arrange the series of blocks one under another , as here exhibited ; it will then be found very easy to pick out the divisors required in rules ( 3 ) and ( 4 ) . -2 --1 -4 -I -2 -1 -6 -1 -1 2421 -3 3 -1 2 -1 -5 811 -4 8 --2 -4 6 -8 . This process cannot be continued when ciphers occur in the interior of any one of the blocks , since infinite values would be introduced by employing them as divisors . When they occur in the given block itself , it may be rearranged as has been already mentioned ; but this cannot be done when they occur in any one of the derived blocks ; in such a case the given block must be rearranged as circumstances require , and the operation commenced anew . The best way of doing this is as follows : Suppose a cipher to occur in the hth row and kth column of one of the derived blocks ( reckoning both row and column from the nearest corner of the block ) ; find the term in the hth row and kth column of the given block ( reckoning from the corresponding corner ) , and transpose rows or columns cyclically until it is left in an outside row or column . When the necessary alterations have been made in the derived blocks , it will be found that the cipher now occurs in an outside row or column , and therefore need no longer be used as a divisor . The advantage of cyclical transposition is , that most of the terms in the new blocks will have been computed already , and need only be copied ; in no case will it be necessary to compute more than one new row or column for each block of the series . In the following instance it will be seen that in the first series of blocks a cipher occurs in the interior of the third . We therefore abandon the process at that point and begin again , rearranging the given block by transferring the top row to the bottom ; and the cipher , when it occurs , is now found in an exterior row . It will be observed that in each block of the new series , there is only one new row to be computed ; the other rows are simply copied from the work already done . 2-1 21 -3 12 -1 2121 -1 21 -1 -2 -1 1 -1 -2 -1 -1 21 -1 -2 -1 21 -1-2 112 -1 -1 21 -2 -1 -1 22 -1 21 -3 5 -5 -3 -3 -3 33 -3 -3 -3 3333 -1 333 -1 -5 -3 -1 -5 -5 -3 -l -5 3 -5 11 -30 6 -12 0060066 -6 86 -6 8 -17 8 -4 0 12 1 18 40 36 . The fact that , whenever ciphers occur in the interior of a derived block , it is necessary to recommence the operation , may be thought a great obstacle to the use of this method ; but I believe it will be found in practice that , even though this should occur several times in the course of one operation , the whole amount of labour will still be much less than that involved in the old process of computation . I now proceed to give a proof of the validity of this process , deduced from a well-known theorem in determinants ; and in doing so , I shall use the word " adjugate " in the following sense:-if there be a square block , and if a new block be formed , such that each of its terms is the determinant of the complemental minor of the corresponding term of the first block , the second block is said to be adjugate to the first , The theorem referred to is the following : " If the determinant of a block = R , the determinant of any minor of the mth degree of the adjugate block is the product of R"- ' and the coefficient which , in R , multiplies the determinant of the corresponding minor . " Let us first take a block of 9 terms , al , a , ,2 a1,3 a,1 a2,2 a2,3 = ; a3,1 a3,2 a3,3 and let ao , , represent the determinant of the complemental minor of a , , , and so on . If we " condense " this , by the method already given , we get the block { 3 , a3 , i , and , by the theorem above cited , the determinant of this , 1,3 a , 1 viz. a3 3,1 Rx a~3'1 I ~R X ~2,2 . 1 , 3 III 1 3,3 3,1 Hence PR= _l3 all I , which proves the rule . 2 , 2 Secondly , let us take a block of 16 terms : al,1. . a.1 , 4* ==R . a4,1. . a4,4 If we " condense " this , we get a block of 9 terms ; let us denote it by , If we take a block consisting of n rows and n+ 1 columns , and " condense " it , we reduce it at last to 2 terms , the first of which is the determinant of the first n columns , the other of the last n columns . Hence , if we take the n simultaneous equations , al , l xl +-al,2 x2+ *** +a , ,x , +-a , n++l=0 , al , XI ... ... ... ... ... . + al , n+1= 0 ; and if we condense the whole block of coefficients and constants , viz. al , 1 ... . al , n+1 l^ * * 0 We then condense these into the column 0 , and , supplying from 23 the second block of the first series the column , we obtain -5 3010 as the last two columns of the second block of the new series ; -5 2 and proceeding thus we ultimately obtain the two terms 12 , 12 . Observing that the y-column has the sign + placed over it , we multiply the first 12 by + y , and so form the equation 12y= 12 , which gives y= 1 . The values of z , u , and v are similarly found . It will be seen that when once the given block has been successfully condensed , and the value of the first unknown obtained , there is no further danger of the operation being interrupted by the occurrence of ciphers . +++2 +2y +zu +2v +2 =0 xy -2z uv -4 =0 2x +yz -2u v -6 =0 x -2y zu +2v +4 =0 2x y +2z +u -3v -8 =0 11 2 1-1 222426|2 511 2 4| 1 -1 -2 -1 -1 -1 -2 -1 -3 -1 -1 |.-.-2v=4 ... . v--2 2 1-1 -2-1 -6 -2 -1 -13 31 1 -2 -1--1 2426 3..3 ... . . 12 -1 2 1-3-8 30 -1 -2 -3-3-3 3 --6 1 16 61 O06 01 12 12 1 6-6 8-2.12y2 . =12 ... ... ... ... ... ... =1 -17 8-4 60 12 12 18 40 -8 136-721.36 . --72 ... ... ... ... ... ... ... ... ... .x ... ... ... ... ... x= 24 5x +2y -3z +3 =Y 3x y -2z +7 =0 2x +-3y -12 =0 52 -3 3 1-3 81 -3 12 3 -1 -2 7 -2 101 . 3=12 ... ... ... ... ... . . z4 231 -12 1-7 -14 -11 --151. . 7y= --14 ... ... ... ... ... . y2 11 5 17 | -22 22..22x=22 ... ... ... ... ... ... ... ... ... . . 1
112608
3701662
An Account of Experiments in Some of Which Electroscopic Indications of Animal Electricity Were Detected for the First Time by a New Method of Experimenting
156
167
1,866
15
Proceedings of the Royal Society of London
Charles Bland Radcliffe
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0038
null
proceedings
1,860
1,850
1,800
12
128
6,225
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112608
10.1098/rspl.1866.0038
http://www.jstor.org/stable/112608
null
null
Electricity
47.030023
Nervous System
13.449843
Electricity
[ -59.87874984741211, -10.343238830566406 ]
I. " An Account of Experiments in some of which Electroscopic Indications of Animal Electricity were detected for the first time by a new method of experimenting . " By CHARLES BLAND RADCLIFFE , M.D. , Fellow of the Royal College of Physicians in London , Physician to the Westminster Hospital and to the National Hospital for Paralysis and Epilepsy , &c. Communicated by CHARLES BROOKE , M.A. Received March 15 , 1866 . Very soon after the discovery of animal electricity by Galvani , I-emmer ascertained that electroscopic indications of electricity might be obtained at the surface of the human body . The instruments used in these investigations were the electroscope of Saussure and the condenser of Volta : the broad result arrived at was-that the indications in question might be sometimes present and sometimes absent ; that they pointed sometimes to positive electricity , and sometimes to negative ; and that they did not depend ( except , perhaps , in a very small degree ) upon the friction of the hair , or skin , or clothes , or carpet . Upwards of sixty years have passed since Hemmer published the account of his labours . During the first half of this period not a little good work was done in this branch of scientific inquiry , especially by Gardini in 1792 , by Ahrens in 1817 , and by Nasse in 1834 ; and what was done is in the main confirmatory of the genuineness of the work done by Hemmer . During the last thirty years , on the contrary , little or nothing has been done* . It seems , indeed , as if the discovery of the galvanometer , now a little more than thirty years ago , had diverted attention from the electroscope : at any rate it is the fact that it has been the fashion since the discovery of the galvanometer to forget the static , and to think only of the current phenomena of animal electricity . Nor is this altogether to be wondered at ; for it must be allowed that the-facilities for detecting the current phenomena of animal electricity are far , very far greater than those for detecting the static phenomena of this agent . Be this as it may , however , my own experience amounts to this-that I found it difficult to detect these latter phenomena easily and satisfactorily until I hit upon the method of investigation employed in the experiments about to be described-a method which dispenses with the use of the condenser , which appears to be as delicate as it is certain and simple , and which I now proceed to describe without any further preamble . I. An account of the method of experimenting employed in the experiments which have to be related presently . In order to carry out this method of experimenting , the instruments necessary are two small electroscopes , two insulating stands upon which to fix these electroscopes , and a conducting rod with an insulating handle . Each electroscope is provided in the usual way with a pair of gold leaves , and with slips of tinfoil in the interior of the glass bell of the instrument , and it has , in addition , an opening underneath the wooden base , by which it may be screwed on the top of the insulating stand . Each insulating stand is a piece of glass rod 9 or 10 inches in length , fixed by its lower end into a suitable foot , and having at the upper end a screw which fits into the opening underneath the wooden base of the electroscope . In one stand ( for reasons which will appear presently ) the glass stem is varnished ; in the other it is left unvarnished . The conducting rod may be of ally form . For the rest , all that need now be said is that , in order to avoid the chance of electricity being developed by the friction of lackered surfaces , the caps of the electroscopes , and the end of the conducting rod which has to be brought into contact with the caps at certain times , are left unlackered , and that , in order to secure as good insulation as possible , the exterior of the electroscopes are well varnished whenever practicable , In preparing for al experiment , the electroscopes are screwed on the insulating stands , and then charged in a particular way with free electricitythe one with free positive electricity , the other with free negative electricity . This charge is obtained by gently rubbing the glass stem of the insulating stands between the finger and thumb the positive electricity from the unvarnished glass stem , the negative from that which is varnished . The electricity thus obtained is communicated , not to the cap , which is in direct communication with the gold leaves , but through the wooden base to the tinfoil slips which run halfway up the interior of the glass bell of the electroscope ; and thus , instead of being charged directly , the gold leaves become charged inductively with the opposite kind of electricity to that which is communicated to the tinfoil slips . The result of doing this is that the gold leaves take up a given degree of divergence , and that they remain divergent so long as the tinfoil slips retain their charge of electricity . Charged in this manner , in fact , the gold leaves cannot be brought together by placing a conductor between the cap of the electroscope and the earth ; indeed , so far from this being possible , the effect of placing a conductor in this position , under these circumstances , is ( as may easily be ulderstood ) to increase the divergence of the gold leaves . s Now what has to be done in preparing for an experiment is to get the gold leaves in that second position of divergence into which they pass when the discharging rod is applied to the cap of the charged electroscope . First of all , the gold leaves are made to diverge to a given degree by charging the electroscope in the manner which has been described ; then the conducting rod is placed in position and the gold leaves are made to take up the full degree of divergence by so doing ; and when this is done the electroscopes are ready for use . The electroscopes being ' set " in this manner , the experiment which has to be performed consists in bringing the body , whose electrical condition has to be examined , to the cap of each electroscope in turn , and in noting the movements of the gold leaves . The experiment is simple , and the results are these . When the body is electrified positively , it causes increased divergence of the gold leaves in the electroscope in which these leaves are electrified with positive electricity ; and vice versed , when the body is electrified negatively , it causes increased divergence of the gold leaves in the electroscope in which these leaves are electrified with negative electricity , and diminished divergence in the electroscope in which these leaves are electrified with positive electricity . These are , as will be easily understood , the movements of the gold leaves which must take place under these circumstances . Moreover the charge of electricity in the electroscope reacts upon the body which is brought to the cap of the instrument , and produces , in a way which is intelligible enough , a certain small amount of increased divergence of the gold leaves of both electroscopes . Now this slightly increased divergence of the gold leaves in both electroscopes is of little or no moment when bodies electrified with comparatively large amounts of free electricity are made to act upon the caps of the instruments , but it is of great moment when these bodies are electrified with minute amounts of free electricity ; for in this case the movements of the gold leaves arising from the action of the free electricity will be exaggerated or masked according as they happen to be in the same direction or in the opposite direction to the movements produced by the reaction of the charge in the electroscopes . Thus , if the degree of increased divergence in the gold leaves of both electroscopes arising from the reaction of the charge in the instruments be = 2 , and if the alteration in the divergence of the gold leaves produced by the action of free electricity be of the same value , that is =2 , the result of this latter action will be , not increased divergence of the gold leaves =2 in one electroscope , and diminished divergence of these leaves =2 in the other instrument , but increased divergence =4 , in the electroscope in which it causes increased divergence ( for in this case it is the action of the free electricity plus that of the reaction of the charge in the instrument , 2+2 =4 ) , and no alteration of divergence in the electroscope in which it causes diminished divergence ( for in this case it is the converging action of the free electricity minus that of the diverging action of the charge in the instrument , that is , 2-2=0 ) , and so also in similar cases , the movement of increased divergence of the gold leaves in both electroscopes arising from the reaction of the charge in the instrument being added to or subtracted from the movement of the gold leaves produced by the action of free electricity , according as these movements happen to be in the same or in opposite directions . These , then , being the facts , it is easy to see how , by using two electroscopes , it is possible to eliminate the reaction of the charge of electricity in the instruments upon the gold leaves , and to make this reaction tell in making more obvious the action of very minute quantities of electricity . It is easy to eliminate the reaction of the charge of electricity in the electroscopes upon the divergence of the gold leaves ; for this reaction causes slightly increased divergence of these leaves in both instruments . It is easy to make the reaction of the charge of electricity in the electroscopes upon the divergence of the gold leaves tell in making more obvious the action of free electricity upon the divergence of these leaves ; for it is plain that in the electroscope in which the action of positive electricity causes increased divergence of the gold leaves , this movement will be aided by the increased divergence of these leaves arising from the reaction of the charge of electricity in the electroscopes , and , vice versed , that in the electroscope in which negative electricity causes increased divergence of the gold leaves this movement will be aided by the increased divergence of these leaves arising from the reaction of the electricity in the instrument . Nor does it follow that one of the electroscopes is in reality superfluous . A priori , indeed , it might be supposed that one electroscope would be sufficient . It might appear enough to take the movements of increased divergence of the gold leaves as evidence of the action of one kind of electricity , and the movements of diminished divergence as evidence of the other kind of electricity . But when dealing with minute quantities of electricity , it is found practically that the movements of diminished divergence are not so easily produced as those of increased divergence , and that there are impediments to free movement in this direction , arising from the clashing of the movement of diminished divergence due to the action of free electricity with the movement of increased divergence due to the reaction of the charge of electricity in the electroscope . In short , the plain truth appears to be , not only that the two electroscopes act as a check upon each other , and show the same thing from two different points of view , but that they furnish evidence which in itself is far more conclusive , when dealing with minute quantities of electricity , than can be got from either instrument singly . In the description of the experiments upon which I am now about to enter , it is necessary to be able to distinguish the two electroscopes the one from the other ; and I propose , therefore , to speak of the instrument in which the gold leaves are charged with positive electricity , and in which positive electricity causes increased divergence of these leaves , as the Positive Electroscope , and-of the instrument in which the gold leaves are charged with negative electricity , and in which negative electricity produces increased divergence of these leaves , as the Negative Electroscope . II . An account of experiments in some of which electroscopic indications of animal electricity were detected by the method of experimenting which has just been described . In this account the degree of movement of the gold leaves is indicated by arbitrary figures . It is assumed also that the increased divergence of the gold leaves in both electroscopes , which movement has been seen to arise from the reaction of the charge of electricity in the electroscope , is =2 ; and in each experiment this figure is added to the movement produced by the action of free electricity in the case where this action causes increased divergence of the gold leaves , and subtracted in the case where this action causes diminished divergence of these leaves . Thus , in the case where the movement of the gold leaves arising from the action of free electricity is =3 , the actual movement of the gold leaves in the instrument in which there is increased divergence of these leaves will be =5 , for 3+2=5 , and in the instrument in which there is diminished divergence of these leaves will be = 1 , for 3-2 =1 . Or , in the case where the movement due to free electricity is =1 , there will be a different degree of increased divergence of the gold leaves in both electroscopes ; for in the instrument in which the action of the free electricity causes increased divergence , the actual movement of the gold leaves will be =3 , for 1+2=-3 ; and in the instrument in which this action tends to cause diminished divergence , this tendency will be overpowered by the increased divergence due to the reaction of the charge of electricity in the electroscope , and the actual movement which results will be one of increased divergence =1 ; for the movement of increased divergence arising from the reaction of the charge in the electroscope , =2 , minus the movement of diminished divergence , = 1 , arising from the action of the free electricity , must be increased divergence = 1 , for 21 =1 . In the account of these experiments , also , certain abbreviations are made use of : thus i. d. stands for increased divergence of the gold leaves , d. d. for diminished divergence of those leaves . For the rest , I have only to add that these experiments , which I leave to tell their own story , with the aid only of a few short comments at the end of each series , supply the first electroscopic indications of electricity in living blood and in living nerve-tissue , and that , to say the least , they clear up all uncertainty as to the presence in the living human body and in living muscular tissue of electricity capable of supplying like indications . First Series.-Experiments which furnish electroscopic indications of electricity in the livinyg human body . In the first four of these experiments all that was done was to apply the palm of my hand or the tips of my fingers to the cap of each electroscope in turn , and to note the movements of the gold leaves produced by so doing . In the fifth experiment , the part experimented upon was brought to the caps of the electroscopes by taking hold of a loop of silk braid which had been previously attached to it . Exp. 1 . In this case the result was d. d. =4 in the negative electroscope , and i. d.=8 in the positive electroscope , -a result showing , as has been already explained , that the electroscopes were acted upon by positive electricity == 6 . Exp. 2.-Here the movements of the gold leaves indicated the action of positive electricity =2 , the facts being-no alteration of the divergence of the gold leaves in the negative electroscope , and i. d.=4 in the positive electroscope . Ex-p . 3 . In this case there was i. d.=2 in both electroscopes-a state of things showing that the hand was electrically neutral at the time , seeing that the movements of the gold leaves were only those which were due to the reaction of the charge of electricity in the electroscopes . Exp. 4.-HIere there was no alteration of the divergence of the gold leaves in the positive electroscope , and i. d.=4 in the negative electroscope-a state of things ( the reverse of what happened in Exp. 2 ) signifying that the electroscopes were being acted upon by negative electricity --2 . Exp. 5.-A part of a foot which had been removed by amputation from a patient in the Westminster Hospital twenty-four hours previously was the part experimented upon in this instance ; and the result was the same as in Exp. 3 , namely , i.d.=2 , in both electroscopes equally the result which is brought about when a body which is electrically neutral is brought to the caps of the electroscopes . *** I have performed experiments like the first four many hundred times , and I have repeatedly tested in the same way the electrical condition of other persons . In the great majority of instances the electroscopic indications were those of positive electricity . Only now and then all electroscopic indications were absent . I have also on several occasions repeated the experiment on portions of the dead body , and always without finding any signs of electricity . More than once , on the same occasion , I have found strong indications of positive electricity in one person , and very feeble indications , or no indications whatever , in another person . More than once also I have been able to detect electricity in my own body , or in the bodies of other persons at an elevation of some feet above the ground , when it was impossible to do so on the ground itself . In fact I have obtained proof of the existence of great variations in the electricity of myself and others at various times and under various circumstances , and I have begun a systematic series of observations with a view to ascertain the electrical condition of the human body at different times and under different circumstances as to health and disease . I have already in this way arrived at some curious results , and I have certainly seen enough to make me hope that a knowledge of the electrical changes in human bodies may shed much light upon the changes which are continually taking place in the vital condition of the human body , especially when the electrical changes within the body are taken in connexion with electrical and other changes without the body . Second Series.-Experiments which furnish electroscopic indications of electricity in living blood . The blood used in this series of experiments was collected in a widemouthed glass bottle capable of holding about 2 oz. Immersed in the blood and projecting to a convenient distance from the neck of the bottle , was a piece of platinum wire . The bottle was provided with a loop of silk braid , which loop was fastened in such a way as to allow the bottle to be lifted up by it without spilling the contents ; and the necessary communication with each electroscope in turn was made by taking hold of the loop and by bringing the platinum wire projecting from the mouth of the vessel into connexion with the cap of the instrument . Exp. 6 . In this case the blood used was from the internal jugular vein of a donkey , and the electroscopic indications obtained were those of negative electricity = 6 , the actual movements of the gold leaves being d. d. =4 in the positive electroscope , and i. d. =8 in the negative electroscope . Exp. 7.-Here the blood was from the internal carotid artery of the same donkey which had furnished the venous blood used in the last experiment ; and the result was also the same , namely , d. d. =4 in the positive electroscope , and i. d. =-8 in the negative electroscope , -a result denoting the action of negative electricity =6 upon the instruments . Exp. 8 . In this experiment blood from the carotid artery of a sheep was examined ; and the movements of the gold leaves were those of positive electricity = 2 , there being no alteration of the divergence of the gold leaves in the negative electroscope , and i. d. =4 in the positive electroscope . Exp. 9.-Here the blood used was from the carotid artery of a dog . The examination was made without loss of time , and the animal seemed to be in good health ; but all signs of electricity in the blood were absent , the movements of the gold leaves being those of i. d. =2 in both electroscopes equally . Exp. 10.-The blood experimented upon in this case was that which had been already used in Exp. 6 , an interval of an hour and a half having elapsed between the two experiments . In the former experiment the blood gave electroscopic indications of negative electricity = 6 ; in this instance these indications had disappeared altogether , for there was i. d. =2 in both electroscopes equally . *** I have repeated experiments like these many times upon the blood of various animals-oxen , sheep , dogs , rabbits , and so on-sometimes upon pure arterial blood , sometimes upon pure venous blood , mo:e frequently upon the mixed stream which follows the knife of the butcher in the ordinary process of slaughtering sheep and oxen . As a rule , I have found decided electroscopic indications of negative electricity indifferently in arterial , venous , or mixed blood ; not unfrequently I have failed to find any such signs . Now and then I have found comparatively feeble signs of positive electricity . In every case also where I have examined blood after an interval of an hour or so from the time when it had flowed fresh from the vessel , I failed to detect any sign of electricity , negative or positive . These experiments no doubt leave much to be discovered in the same direction , but this at least they do , they furnish the first electroscopic proof of the presence of electricity in living blood . Nay , it is perhaps not too much to say that they supply the first unequivocal proof of electricity in blood , for the current electricity recently obtained from blood by M. Scoutteten and Dr. Shettle may in reality be nothing more than the result of chemical and other changes produced by the blood upon the terminal wire of the galvanometer used in these experiments . Third Series.-Experiments which furnish electroscopic indications of electricity in living nerve-tissue . The plan adopted in this series of experiments was to the a loop of silk braid to the part to be experimented on , and to use this loop as the means for bringing this part to the cap of each electroscope in turn . Exp. 11.-The medulla oblongata of an ox obtained a few minutes after the animal had been killed in the ordinary way in the shambles , was the part used in this experiment . At one time the cut surface exposing the transverse section of the fibres and the internal grey matter was brought to the caps of the electroscopes ; at another time the uncut surface corresponding to the longitudinal surface of the fibres was treated in this manner ; and in each case the movements of the gold leaves were indicative of the action of positive electricity = 6 , or thereabouts , the only difference perceptible being a slight one of degree . The average movements obtained were those of d. d. =4 in the negative electroscope , and i. d. =8 in the positive electroscope . Exp. 12.-The brachial enlargement of the spinal cord of an ox , taken out of the canal when the carcass was being split into two lateral halves at the usual time , that is , about half an hour from the moment when the animal had been felled with the pole-axe , was used in this experiment , and the result was d. d. =4 in the negative electroscope , and i. d. =8 in the positive electroscope . It was found also that this result was the same , except in some trifling difference in degree , in the case where the transverse sectional surface of the fibres was brought to the caps of the electroscopes , and in the case where the longitudinal surface of these fibres , natural or artificial , was examined in this manner . Exp. 13.-Here the part examined was the posterior lobe of the cerebrum of a sheep which had been killed in the usual way a few minutes previously in the shambles . No time was lost in making the necessary preparations , but not the slightest indications of electricity were obtainable , the movements being only those of i. d. =-2 in both electroscopes equally . Exp. 14.-The cerebellum of a sheep was examined in this experiment , and the result was-no alteration in the divergence of the gold leaves in the negative electroscopes , and i. d. =4 in the positive electroscopes , a state of things indicating the action of positive electricity =2 upon the instruments . It was ascertained also that all parts of the cerebellum indifferently behaved in the same manner . Exp. 15 . In this experiment the brain of a donkey just killed by loss of blood was examined , and it was found that all parts of the surface indifferently , natural or artificial , gave similar indications of negative electricity == 4 , there being d. d. =2 in the positive electroscope , and i. d. =6 in the negative electroscope . Exp. 16.-The brain of the donkey used in the last experiment was used also in this instance , an interval of an hour , or thereabouts , having elapsed between the two experiments . When first examined this organ gave indications of negative electricity = 4 ; now it was found to have lost all traces of electrical activity everywhere , for the movements of the gold leaves were simply those of i. d. =2 in both electroscopes equally . ** These experiments , as I believe , bring to light a new fact , inasmuch as they furnish the first electroscopic proof of the presence of electricity in living nerve-tissue . Judging from these and several other experiments of the same kind , in which dogs and rabbits , as well as oxen , sheep , and donkeys , were put under contribution , it would seem that living nerve-tissue , as a rule , fiurnishes electroscopic signs of electricity , sometimes positive and sometimes negative in character , and that these signs are always absent when the nerve-tissue may be supposed to have lost all traces of vitality . And this also would seem to be a conclusion deducible from the same evidence-that all parts of the nerve-tissue present signs of the same kind of electricity . It would seem , in fact , as if these experiments suggested a conclusion which is at variance with a conclusion drawn by Professor Du Bois Reymond from some of his experiments . Watching the direction of the " nerve-current " which passes through the galvanometer between the longitudinal surface , natural or artificial , of the nerve-fibres , and the transverse sectional surface of these fibres , Professor Du Bois Reymond comes to the conclusion that these two surfaces are in opposite electrical conditions , the one being positive , the other negative . Because the current passes in a particular direction , he infers that these surfaces must be electrified with different kinds of electricity . But it is plain that the current might pass between parts electrified with different degrees of the same electricity ; and indeed M. Du Bois Reymond himself explains the current passing between two points of the same surface in this manner ; and therefore , even on his own showing , there is no necessity to suppose that the longitudinal surface of the nerve-fibres is electrified with one kind of electricity and the transverse sectional surface of the fibres with the other kind . At any rate , the facts revealed by the electroscope do not appear to be of doubtful significance , and the only inference which I can deduce from them is that every part of the surface of living nerve-tissue , natural or artificial , furnishes signs of the same kind of electricity , and that the only electrical differences between one part and another are nothing more than differences of degree . Fourth Series.-Experiments which furnish electroscopic indications of electricity in living muscular tissue . In this series of experiments the mode of proceeding was the same as that adopted in the last series . Exp. 17.-The piece of muscle examined in this experiment was cut out of the sterno-niastoid of an ox a few moments after the animal had been killed in the shambles , and every part of the surface was tested in turn , and , except in some trifling difference in degree , the movements of the gold leaves were in all cases indicative of the action of positive electricity = 6 , these movements being those of d. d. =4 in the negative electroscope , and those of i. d. =8 in the positive electroscope . Exp. 18.--Here the sterno-mastoid of a sheep just killed in the ordinary way in the shambles , furnished the material for experiment , and the result was-no alteration in the divergence of the gold leaves in the negative electroscope , and i. d. =4 in the positive electroscope-a result showing the action of positive electricity =2 upon the electroscopes . Exp. 19 . In this instance the portion of muscle examined was taken from the glutneus maximus of a donkey which had just been killed by hbemorrhage , and it was found that all parts of the surface indifferently supplied indications of negative electricity = 1 , the movements of the gold leaves being those of i. d. =I in the positive electroscope , and i. d. 3 in the negative electroscope . Exp. 20.-A piece of the left ventricle of the heart of a dog just dead from haemorrhage was examined in this instance , and the only movements of the gold leaves were those which are produced by the action of a body electrically neutral , namely , i. d. =2 in both electroscopes equally . Exp. 21.--Iere the piece of muscle experimented upon was that used in Exp. 17 . Twelve hours had elapsed between the two experiments , and rigor mortis had now fully set in , and the result showed that the positive electricity which was present formerly was no longer present , the movements of the gold leaves being simply those of i. d. =2 in both electroscopes equally . *** With the exception of an experiment in which Professor Matteucci incidentally states that he obtained signs de tension avec un condensateur delicat " from one of his " ( muscular piles , " these experiments furnish , so far as I know , the only electroscopic indications of the presence of electricity in living muscular tissue-perhaps the very first really distinct proofs of this fact . I have repeated these experiments several times on r the muscles , living and dead , of various animals , oxen , sheep , donkeys , dogs , and rabbits , and I have found in the great majority of instances that all parts of the surface of living muscle furnished indications of the same kind of electricity , that this electricity was sometimes positive , sometimes negative , and that these signs were invariably absent in muscle which had passed into the state of rigor mortis . These experiments , moreover , make it difficult to agree with Professor Du Bois Reymond in thinking that the longitudinal surface , natural or artificial , of the muscular fibres , and the transverse sectional surface of these fibres , are electrified with different kinds of electricity . With respect to the electricity of muscular tissue , indeed , it seems to he precisely as it is with respect to the electricity of nerve-tissue , namely this , that all parts of the surface are electrified with the same kind of electricity , positive or negative , as the case may be , the only difference between one part and another being one of degree ; and the comments upon M. Du Bois Reymond 's conclusions , when speaking upon the condition of nerve-tissue as to electricity , are equally applicable to the present case , if only the words muscular tissue and muscular current be substituted for nerve-tissue and nerve-current . In conclusion , it only remains for me to direct attention to one bearing of the facts recorded in this paper . These facts , one and all , exhibit animal electricity , not in the form of a feeble nerve-current , or of a feeble muscular current , or of the still feebler currents of less definite character , but as endowed with a considerable amount of tension . They bring to light a property of animal electricity which is more intelligible on the supposition that the primary condition of this electricity is not current but statical . It is easy to account for these phenomena of tension if the primary condition of animal electricity be statical , for tension is the characteristic property of statical electricity ; it is by no means easy to account for these phenomena of tension if the primary condition of animal electricity be that of the current revealed by the galvanometer , for the currents so revealed are far too feeble to allow one to suppose that they can be endowed with an appreciable amount of tension . In a word , with the phenomena of tension to account for which are revealed in the experiments recorded in this paper , the natural inference , as it seems to me , is that the primary condition of animal electricity is , not current , but statical , and that the currents made known by the galvanometer to which so much attention has been paid of late the muscular current , the nerve-current , and the rest-are secondary phenomena developed accidentally by placing the ends of the coil of the galvanometer so as to include points in which the electricity is different in degree . Nay , it would seem that these currents may in reality be a retarded discharge of statical electricity , for it is a fact that they cannot be detected without a coil of which the wire is so long and so fine as to be capable of giving sufficient resistance to bridle a discharge into the quieter pace of ordinary currents . Many important consequences in physiology and in pathology , as I think , result directly or indirectly from this view of the matter , of which some are set forth in some Lectures which I gave at the College of Physicians in London three years ago , and which have since appeared in print ; but it is no part of my present task to consider these consequences . Indeed , what I proposed to do in this paper I have now done ; and this was simply to direct attention to certain facts as facts , and to offer certain passing comments suggested naturally by these facts .
112609
3701662
On the Dynamical Theory of Gases. [Abstract]
167
171
1,866
15
Proceedings of the Royal Society of London
J. Clerk Maxwell
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
5
76
2,253
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112609
null
http://www.jstor.org/stable/112609
null
108,968
Fluid Dynamics
54.733565
Thermodynamics
33.675551
Fluid Dynamics
[ 35.37896728515625, -34.23914337158203 ]
II . " On the Dynamical Theory of Gases . " By J. CLERK MAXWELL , F.R.S. L. & E. Received May 16 , 1866 . ( Abstract . ) Gases in this theory are supposed to consist of molecules in motion , acting on one another with forces which are insensible , except at distances which are small in comparison with the average distance of the molecules . The path of each molecule is therefore sensibly rectilinear , except when two molecules come within a certain distance of each other , in which case the direction of motion is rapidly changed , and the path becomes again sensibly rectilinear as soon as the molecules have separated beyond the distance of mutual action . Each molecule is supposed to be a small body consisting in general of parts capable of being set into various kinds of motionl relative to each other , such as rotation , oscillation , or vibration , the amount of energy existing in this form bearing a certain relation to that which exists in the form of the agitation of the molecules among each other . The mass of a molecule is different in different gases , but in the same gas all the molecules are equal . The pressure of the gas is on this theory due to the impact of the molecules . on the sides of the vessel , and the temperature of the gas depends on the velocity of the molecules . The theory as thus stated is that which has been conceived , with various degrees of clearness , by D. Bernoulli , Le Sage and Prevost , Herapath , Joule , and Kronig , and which owes its principal developments to Professor Clausius . The action of the molecules on each other has been generally assimilated to that of hard elastic bodies , and I have given some applica* It is to be supposed that certain molecules in living animal bodies are , under certain given conditions , a constant source of electricity-are so , perhaps , in the way in which certain molecules of the electrophorus are such a source . The idea is that this electricity is so supplied as to admit of a series of frequent discharges , or to keep up a constant current if these discharges are retarded sufficiently . At any rate , it does not follow that this constancy of the current of animal electricity detected by the galvanometer is an objection in itself to the idea that the primary condition of animal electricity may be , not current , but statical . 167 tion of this form of the theory to the phenomena of viscosity , diffusion , and conduction of heat in the Philosophical Magazine for 1860 . M. Clausius has since pointed out several errors in the part relating to conduction of heat , and the part relating to diffusion also contains errors . The dynamical theory of viscosity in this form has been reinvestigated by M. O. E. Meyer , whose experimental researches on the viscosity of fluids have been very extensive . In the present paper the action between the molecules is supposed to be that of bodies repelling each other at a distance , rather than of hard elastic bodies acting by impact ; and the law of force is deduced from experiments on the viscosity of gases to be that of the inverse fifth power of the distance , any other law of force being at variance with the observed fact that the viscosity is proportional to the absolute temperature . In the mathematical application of the theory , it appears that the assumption of this law of force leads to a great simplification of the results , so that the whole subject can be treated in a more general way than has hitherto been done . I have therefore begun by considering , first , the mutual action of two molecules ; next that of two systems of molecules , the motion of all the molecules in each system being originally the same . In this way I have determined the rate of variation of the mean values of the following functions of the velocity of molecules of the first system:a , the resolved part of the velocity in a given direction . 3 , the square of this resolved velocity . y , the resolved velocity multiplied by the square of the whole velocity . It is afterwards shown that the velocity of translation of the gas depends on ox , the pressure on 1 , and the conduction of heat on y. The final distribution of velocities among the molecules is then considered , and it is shown that they are distributed according to the same law as the errors are distributed among the observations in the theory of " Least Squares ; " and that if several systems of molecules act on one another , the average vis viva of each molecule is the same , whatever be the mass of the molecule . The demonstration is of a more strict kind than that which I formerly gave , and this is the more necessary , as the " Law of Equivalent Volumes , " so important in the chemistry of gases , is deduced from it . The rate of variation of the quantities a , 3 , y in an element of the gas is then considered , and the following conclusions are arrived at . ( a ) 1st . In a mixture of gases left to itself for a sufficient time under the action of gravity , the density of each gas at any point will be the same as if the other gases had not been present . 2nd . When this condition is not fulfilled , the gases will pass through each other by diffusion . When the composition of the mixed gases varies slowly from one point to another , the velocity of each gas will be so small that the effects due to inertia may be neglected . In the quiet diffusion of two gases , the volume of either gas diffused through unit of area in unit of time is equal to the rate of diminution of pressure of that gas as we pass in the direction of the normal to the plane , multiplied by a certain coefficient , called the coefficient of interdiffusion of these two gases . This coefficient must be determined experimentally for each pair of gases . It varies directly as the square of the absolute temperature , and inversely as the total pressure of the mixture . Its value for carbonic acid and air , as deduced from experiments given by Mr. Graham in his paper on the Mobility of Gases , * is D=0'0235 , the inch , the grain , and the second being units . Since , however , air is itself a mixture , this result cannot be considered as final , and we have no experiments from which the coefficient of interdiffusion of two pure gases can be found . 3rd . When two gases are separated by a thin plate containing a small hole , the rate at which the composition of the mixture varies in and near the hole will depend on the thickness of the plate and the size of the hole . As the thickness of the plate and the diameter of the hole are diminished , the rate of variation will increase , and the effect of the mutual action of the molecules of the gases in impeding each other 's motion will diminish relatively to the moving force due to the variation of pressure . In the limit , when the dimensions of the hole are indefinitely small , the velocity of either gas will be the same as if the other gas were absent . Ience the volumes diffused under equal pressures will be inversely as the square roots of the specific gravities of the gases , as was first established by Grahamt ; and the quantity of a gas which passes through a thin plug into another gas will be nearly the same as that which passes into a vacuum in the same time . ( 3 ) By considering the variation of the total energy of motion of the molecules , it is shown that , 1st . In a mixture of two gases the mean energy of translation will become the same for a molecule of either gas . From this follows the law of Equivalent Volumes , discovered by Gay-Lussac from chemical considerations ; namely , that equal volumes of two gases at equal pressures and temperatures contain equal numbers of molecules . 2nd . The law of cooling by expansion is determined . 3rd . The specific heats at constant volume and at constant pressure are determined and compared . This is done merely to determine the value of a constant in the dynamical theory for the agreement between theory and experiment with respect to the values of the two specific heats , and their ratio is a consequence of the general theory of thermodynamics , and does not depend on the mechanical theory which we adopt . 4th . In quiet diffusion the heat produced by the interpenetration of the gases is exactly neutralized by the cooling of each gas as it passes from a dense to a rare state in its progress through the mixture . 5th . By considering the variation of the difference of pressures in different directions , the coefficient of viscosity or internal friction is determined , and the equations of motion of the gas are formed . These are of the same form as those obtained by Poisson by conceiving an elastic solid the strain on which is continually relaxed at a rate proportional to the strain itself . As an illustration of this view of the theory , it is shown that any strain existing in air at rest would diminish according to the values of an exponential term the modulus of which is,10 ooo , o second , an excessively small time , so that the equations are applicable , even to the case of the most acute audible sounds , without any modification on account of the rapid change of motion . This relaxation is due to the mutual deflection of the molecules from their paths . It is then shown that if the displacements are instantaneous , so that no time is allowed for the relaxation , the gas would have an elasticity of form , or " rigidity , " whose coefficient is equal to the pressure . It is also shown that if the molecules were mere points , not having any mutual action , there would be no such relaxation , and that the equations of motion would be those of an elastic solid , in which the coefficient of cubical and linear elasticity have the same ratio as that deduced by Poisson from the theory of molecules at rest acting by central forces on one another . This coincidence of the results of two theories so opposite in their assumptions is remarkable . 6th . The coefficient of viscosity of a mixture of two gases is then deduced from the viscosity of the pure gases , and the coefficient of interdiffusion of the two gases . The latter quantity has not as yet been ascertained for any pair of pure gases , but it is shown that sufficiently probable values may be assumed , which being inserted in the formula agree very well with some of the most remairkable of Mr. Graham 's experiments on the Transpiration of Mixed Gases* . The remarkable experimental result that the viscosity is independent of the pressure and proportional to the absolute temperature is a necessary consequence of the theory . ( y ) The rate of conduction of heat is next determined , and it is shown 1st . That the final state of a quantity of gas in a vessel will be such that the temperature will increase according to a certain law from the bottom to the top . The atmosphere , as we know , is colder above . This state would be produced by winds alone , and is no doubt greatly increased by the effects of radiation . A perfectly calm and sunless atmosphere would be coldest below . 2nd . The conductivity of a gas for heat is then deduced from its viscosity , and found to be 51 po M3 y-po0 S ' where y is the ratio of the two specific heats , p0 the pressure , and po the density of the standard gas at absolute temperature 0o . S the specific gravity of the gas in question , and p its viscosity . The conductivity is , like the viscosity , independent of the pressure and proportional to the absolute temperature . Its value for air is about 3500 times less than that of wrought iron , as determined by Principal Forbes . Specific gravity is *0069 . For oxygen , nitrogen , and carbonic oxide , the theory gives the conductivity equal to that of air . I-ydrogen according to the theory should have a conductivity seven times that of air , and carbonic acid about i of air .
112610
3701662
On the Means of Increasing the Quantity of Electricity Given by Induction-Machines
171
182
1,866
15
Proceedings of the Royal Society of London
T. Romney Robinson
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0040
null
proceedings
1,860
1,850
1,800
12
269
5,993
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112610
10.1098/rspl.1866.0040
http://www.jstor.org/stable/112610
null
null
Electricity
54.301466
Tables
12.868433
Electricity
[ 26.517742156982422, -57.71742248535156 ]
III . " On the means of increasing the Quantity of Electricity given by Induction-Machines . " By the Rev. T. ROMiNEY ROBINSON , D.D. Received May 10 , 1866 . Among the remarkable results obtained by studying the spectra of electric discharges , is the change exhibited by certain substances when the nature of the discharge is varied . In general the mere spark shows fewer and fainter lines than when a Leyden jar is in connexion , though the amount of electricity supplied by the machine is the same . In the latter case , however , the discharge passes almost instantaneously , and therefore its concentrated action will be more powerful . But , as far as I know , much has not been attempted towards increasing the power of the jar : this cannot be done by increasing its surface ( unless indeed that be too small to condense all the electricity supplied ) ; the supply itself must be increased . This may be done in three ways : First , the power of the exciting battery may be increased . This , however , is limited by the risk of destroying the acting surfaces of the rheotome ; and by the decreasing rate at which the magnetism of the iron core increases with the primary current . In some investigations on the electromagnet ( Trans. Irish Academy , vol. xxiii . p. 529 ) I have shown that its lifting power L is approximately given by the equation A , B+ ' in which 'I* is the product of the current and number of spires , A the maximum lift of the magnet , and B the T which would excite it to half A. The rate of change is therefore inversely as ( B+t'i)2 . The results obtained with two of the magnets which I used will illustrate this . Their A 's are 781 lbs. and 278 . The first 1000 of ' make their lifts 576 and 235 ; the second 1000 adds to these 87 and 19 ; the third 35 and 8 ; and the fourth only 19 and 3 . With a primary of 180 spires , T=4000 implies a current which can evolve in a voltameter 34'7 cubic inches of gases per minute , and of course has great de'flagrating power . There is therefore not much to be gained in this direction . Secondly , the secondary helix may be made of longer or thicker wire . It will be shown immediately that the length does not increase the quantity of the current at all , and that the effect of the thickness is limited . Thirdly , the analogy of the voltaic battery suggests the plan of combining several helices collaterally , as is done when cells are arranged for quantity ; and this I think may avail to a very great extent . In spectral work , as in most other applications of the inductorium ( as the Germans have named it ) , the breaking current alone is of importance : the other , though equal in quantity , is so much inferior in tension that it is stopped by a thin film of highly rarefied air* . This current proceeds from two causes . When the circuit is broken , the current in the primary ceases ; not instantaneouslyt , but in a time which is very small ; according to Edlund less than -L ? of a second . During its decline it induces a current in the secondary . But while it was passing it had magnetized the iron core of the apparatus : this magnetism now passes away , and in doing so it also induces a current in the secondary , which lasts longer and is more powerful than the other . I compared the two by measuring those given when the core was removed from a primary , and when it was in its place : they were as 1 : 862 when the rheotome made 17 discharges in a second ; so that in round numbers the electric induction was only a tenth of the whole effect . I shall therefore in what follows confine myself to the magnetic induction . If y be the magnetism at any time t , M its maximum , P the potential of the magnet on the secondary helix , I the potential of that helix on itself , r the resistance of the secondary circuit , q the secondary current at the time t , we have , as is well known , P die _ do q= . x d ... ... . . ( a ) r dt rdt the last term being the counter current produced by the reaction of q on the helix . If the inductive coefficient of electric action be different from that of magnetic , II should be multiplied by a factor e , which in ( b ) will multiply I in the exponent and denominator . I see no reason why they should differ unless some work be lost by molecular changes in the core when excited . The great difference between the two currents which I have just mentioned arises most probably from the different values of t in the exponentials . To integrate ( a ) we must assume some relation between die and dt . The most probable is that the loss of magnetism is as the magnetism , which gives dy= -dt , whence y= Me- " . Putting b = , and supposing q to vanish with t , PMX { ( } ... . *)r)ir The total current in the time t=-= dt s--dy-Id , and hence putting F for -P ( M-y ) and c for ~i , we obtain rm The expression for the current due to the electric induction will be similar to this , so far as having the factor F and the exponential . If , as is not unlikely , the relation of dE to dt be the same as for the magnetism , they would only differ in the values of p and c. The quantity F is the current which would be produced were it not for the inductive reaction of the current on itself . It is as P directly and r inversely . The first of these , P , is as n the number of spires in the helix* multiplied by a rather complex function of its length and diameter , which is constant when they are given . The second , r , may be assumed proportional to the length and section of the wire of the helix , for in general the other resistances of the circuit are comparatively small . Hence it follows that If two equipotential helices equally excited be placed in series , the tension will be doubled ; but the current will be intermediate between that of each , for F= 2P , and if r=rw it will not be changed . If they be used collaterally ( their homonymous terminals connected ) , P remains unchanged , and therefore the currents of the helices are simply added. . If there be an external resistance , allowance must be made for it . This may be extended to any number of helices ; for calling the external resistance p , we find P Pt PP + ... . F , T 1 o+ n +. . s ... a ( .d 1 Pr ? t..9.+ r , j The constant c must be a small fraction , for in any ordinary work of the inductorium the residual ' magnetism of the core is very feeble . As i t=e-~t , pt must be large ; and as t for wire cores does not exceed a few hundredths of a secondt , , must be very large . Rev. T. 1I . Robinson on increasing the The potential II is as n2 multiplied by another function of the length and diameters of the helix ( see Maxwell 's valuable paper " On the Electromagnetic Field , " Phil. Trans. 1865 ) ; and the term b is always less than unity . When helices are consecutive their rI 's are added , not when collateral . From this it follows that --c may be neglected ; that -1is nearly unity ; and that the difference between F and ( D increases as 6 diminishes . When equal helices are consecutive , 6 as well as F are unchanged ; therefore so is 4 . When they are collateral , each separate b remains unchanged ( unless they be so close that they react on each other ) ; and therefore , as with F , the resultant ? is the sum of its components . If the resistance of the wire be diminished by increasing its section without making much change in the dimensions of the helix , b is diminished , and therefore the coefficient of F. It is evident from the form of equation ( c ) that ? has a maximum for r , and that beyond this there is actual loss of power in increasing the thickness of the wire . It remained to test these views by experiment , but the task has some difficulties . A single discharge of inductive electricity is usually determined by the swing which it causes in a galvanometer needle ; but it is scarcely possible to get two discharges exactly equal . The slightest variation in the manner of breaking the circuit , the least oxidation or roughening of the surfaces where the break is made , change the result ; and therefore it seemed best to take the actual working of the inductorium , in hopes that the average of some thousand discharges must be near the real value of the current . The rheometer which I used is Weber 's ( for the use of which I am indebted to the kindness of Mr. Gassiot ) , and it showed an amount of fluctuation even greater than I expected . With every precaution as to the action of the rheotome , the mirror of the Weber never becomes stationary , and the oscillations are irregular ; twelve of them were taken for each set , of course read at each end and reduced by the usual formula ; yet the sets differ so much , that I only offer their results as tolerable approximations . Two facts illustrating this uncertainty may be mentioned . With a mechanical rheotome driven at a uniform speed , and its acting surfaces platinum , the ratios of the current wereWhen set so that the point rises but little from the anvil. . 1'0000 Rise greater ... ... ... ... ... ... ... ... ... ... ... . . ] 7894 Rise still greater , tension of spring greater ... ... . . 19685 Rise still greater , tension further increased . 1'8371 Here a slight change of the adjustment nearly doubles the action of the inductoriulm . Another cause of uncertainty is the variable speed of the rheotome . In general it is worked by the primary current , and therefore is affected by fluctuation of the battery and the extra current of the primary . The me chanical rheotome which I have mentioned is driven by clockwork , and its speed can be exactly regulated . With it I obtained 1 . Time of rheotome 's stroke =0'2865 . Current =-1'0000 2 . , , , 0-2020 . , , 0-9298 3 . , , , , 01862 . , , 08741 4 . , , , 0-1381 . , , 07235 5 . , , , 0-1219 . , , 0-5771 6 . , , , 0-1201 . , , 05588 7 . , , , , 00983 . , , 03788 8 . , , , , 00883 . , , 02823 9 . , , , , 00671 . , , 02478 10 . , , , , 0-0476 . , , 02007 11 . , , , , 0-0278 . , , 01946 12 . , , , , 00196 . , 0-1273 13 . , , , , 00098 . , , 00470 No. 10 was taken with a mercurial rheotome ; and the remaining three with a spring one , such as Mr. Lad applies to his inductoria* . This decrease of power is due to the core requiring time to be mag . netized . Suppose the current =A+ Bt A being that caused by the electric induction , B by the magnetic , I get from the above by minimum B squares A=0'0802 ; B-=4'1713 ; =508 ; which values represent the observations pretty fairly , the probable error being + 0'049 1 . Three cells were used here : on another trial with five I had -= 129 , confirming a previous remark that the electric induction increases faster than the magnetic . Hence much power is lost by working at too high a speed . The inductorium which I use consists of a strong oak table , on which are fixed vertically four primary helices , their axes being 12 and 18 inches apart ; at which distance the mutual action of the secondary helices is scarcely sensible in the Weber . I denote these primaries by P ' , Pt ' , &c. Their wire is No. 12 ; Pt and Pt ! are 12-5 inches long ; they have , in four layers , the first 383 spires , the second 343t . Their cores of iron wire , No. 18 , are 1'12 diameter . PlT and Piv are 13-5 inches long ; they have each 181 spires in two layers , and their cores are 1'60 diameter . They are all insulated by strong glass jars , and their connectors are so arranged that the current can be sent through any one separately , or through all at once . The normal arrangement is that the battery-current passes through P1p , then through Pf and P'T collateral , and lastly through P'v . Thus the 4t or exciting power of each primary is nearly the same . On a shelf below stands a Fizeau 's condenser , each of whose coatings is 120 feet divided into k For the first nine of these the time was given by the clockwork of the rheotome ; for the rest by dropping sparks on a slip of prepared paper , which was made to travel at the rate of 12 inches per second . t The difference arose from the cotton lapping being thicker in P " . five sections . This , though so potent in respect of sparks , does not affect the quantity , which with it I found as 1'0000 , without it 0-9948 , a difference not worth noting . The case , however , would be different if there were a gaseous interval in the circuit * . Beside this shelf is a bracket which supports rheotomes of various kinds . Over the jars can be put any of the secondary helices , the constants of which are given in the following Table : The potential P and resistance of the first one , which I take as a standard , are assumed = 1 . TABLE I. Feet of Diameter Entire ghtPotential . lsistance . wire . of wire . ayer . Spire . diameter . HeighResistance . in . in . in . G ... ... . . 17,070 0-0092 73 I3,655 6'84 40 00000ooooo 0000oooo H ... ... . 17,070 0-0092 73 I3,655 6-84 40 0000ooooo 085270 I ... ... ... 8 , 0'I53 55 6,570 6'72 4'0 0'481I4 ooo0079 K ... ... ... 8,0 o'oI53 55 6,570 6'72 4'0 0'48I14 100oo79 M ... ... . 8,130 0o'o92 29 6,524 6'2I 6'o 0'47520 0'08073 N ... ... . . 8 , I30 ' ooi92 29 6,524 6*56 5'9 0'47520 o'08z82 A ... 7,000 0-0107 ... 6 , i89 5'93 3'5 044673.8o B ... . , ... . 9,200 o'o107 ... 8,135 5'93 4-0 0o60272 J50 The first six were made by Mr. Lad , who also determined for me the length and number of layers . The thickness of the wires was measured by me with a fiihlhebel which read to 0'0001 : each is a mean of ten measures at different places , for no wire that I have ever tried is quite uniform . The two last are experimental , their wire not being lapped , but merely insulated by a varnish of wax and rosin , as proposed by the late Dr. Callan : this plan does well for quantity , but cannot be trusted for any high tension . The potentials were computed , supposing the helices at the middle of tke primary Pht ( where they are a maximum ) . For GI computed them in four other positions , and had the curiosity also to measure the currents . Distance of G from centre =0 , potential 1'0000 , current 1 0000 , , , , 1 , , , 0'9842 , , , 0'9856 2 , , , 0'9790 , , , 0-9746 , , , , 3 , , , 0'9488 , , , 09488 , , , , 4 , , , 0-8798 , , 0'9181 All but the last agree tolerably . For positions of M and N , which were not central , they were specially computed . The resistances were obtained by including in the circuit of a small Grove 's cell and a tangent rheometer of 950 spires , first the helix G , then that to be determined , and lastly the sum of it and G. Assuming G= 1 , we have three equations to determine the r of the helix in question , the remaining r of the circuit , and the electromotive force of the cell . In deducing the currents , the term involving sin20 was used with a coefficient obtained by integrating through the length and breadth of the rheometer 's coil ; and as its mean diameter is 6*4 times the length of its needle , and 0 never passed 54 ? , I think the numbers of the Table are true to the last decimal . For brevity I symbolize the combinations , when in series , as a sum , G+ I ; when collateral , as a product G. H ; and for a reason which will soon appear , when two are on the same primary I denote them by a new letter , as V=G+I . At first I used I and G on Pt ; K and H on p"v . To prevent disruptive discharge , they were kept 1*5 inch asunder by disks of baked wood . The results are given in TABLE II . Sum of Name . < . FB.'* Spark . Sets . c ntb . F components . in . G ... , ... ... . . oooo 00oooo 3'95 ... I00000 oo ... ... 'o 00779 ... ... ... . . I'000ooo 3'37 ... . . I00000o 0'985385 G+H ... ... 1I0348 I-0096+. . 3 102497 ... 2'00000 0-92306 G.H. . , ... -9988 2'0223 ... 4 98837 2-0855 I'0oo I ... ... ... ... 2-5343 4'3635 1'3 I 0'59x67 . 'z23149 0'46542 I+K ... ... 27654 4'5358 2V49 3 o'60969 0 ... . o-46298 0'44872 ( LI-K). . 3'552 6'5756 o'8o 4 0'46462 46220 V+V ' ... ... 0'9996 1'3776 9'35 3 0'72562 ... ... 2z46298 o083075 V.V ' ... ... '9434 2'7319 4'39 I 0'71138 F is computed with a correction for the place of the helix on the primary , and with a resistance which includes that of the Weber =0'00779 . The Weber must have a considerable n of its own ; but as I did not know its constants , and as this r must vary with the deflection , I did not compute it . Possibly some of the discrepancies may be owing to this . The sparks show the difference of tension ; they were taken with platinum points , and when the machine was excited by four Groves . The column , sum of components , gives for the collateral combinations the values which arise from adding the 4F of each helix , taking into account the Weber 's resistance . 1 . It will be observed that G+H with twice as many spires , and V+ Vt with thrice as many as G , give the same current ; so also that of I+ K is near that of I. 2 . On the other hand , G. IH is twice G , and V. V ' twice V+Vt . 3 . It is also manifest that the effect of I is not proportional to its diminished resistance : its F is 4'4 times greater than that of G , but its actual current is only 2'5 . This is at once explained by its b being so much less . So also the ratio of the theoretic to the effective current is nearly unity in G+I , while it is only 0'73 in V+Vt , and for the same reason . In G. H. ( I+K ) the ratio is still smaller ; but I shall recur to this . I now used the four primaries I+ K-L on Pv , single helices on the others . I had some doubt whether the difference of the cores might not influence the results , and tried this with P ' , P't , and one Pv , whose core =1'90 inch in diameter and 15'5 inches long . It has 349 spires of No. 15 in two layers . G was put on each of them , and currents transmitted , which made their ' 's nearly equal . TABLE III . Name . Sect. Sets . Spark . 'F . core as P/ ... ... ... ... r'oo r 0414 3'5 2z225 1169 iv ... ... ... ... 204 'o0000 2 3'237 ii68 pv ... ... ... ... . 300 10054 2 ' 2'662 1156 It follows from this that the least of these cores is large enough for the excitation produced by four cells : the size does seem to increase the spark , though this increase may be owing to better insulation of the core-wires in P"t and Pvt . The following results were obtained with the mechanical rheotome worked at a uniform speed of 13 discharges per second . TABLE IV . 4 . F. Sets . m of . b. components . 0 00 ... ... 00 ... ... . . 0oooo 00oooo. . ooooo ... ... I'ooooo ' 00779 L=I--K ... I'8832 4'5o06 19 0'4I752 ... ... 0'6+ 034624G+L ... ... ... I'3149 I'643 2 '-81451 ... . . 16+ 0'75002G . L ... ... ... 3 '0402 5'3I09 II o'57I59 2'8324 H ... ... ... ... . 4196 I3578 2 I104551 ... ... 'o00000 0'85385 C=A+B ... 1-9882 2'01o2 2 0'99855 ... ... 0'56286+ 0'92704 N ... ... ... ... ... 2-5535 5'4o00 I 0'47202 ... ... o'3 646 0'27756 I ... ... ... ... ... 25580 4'3635 2 0'58623 ... ... 2349 0'46542 K ... ... ... ... ... 26465 4'3635 5 o6o65i. . o0'23I49 o'46542 G.K ... ... ... . 3-5558 5'2464 I 0'67776 3'8594 - . I. l T ... ... 4'3I79 6'5756 3 o065666 4'1799 G.L.C ... ... . 5'460 6'9400 3 o'74I53 4'6932 G.L.C.II ... 6'0758 8'zo8i 3 0'74030 6'0488 M I+N ... ... ... 252o7 5'4586 2 0-46179 0 ... . . o'63292 0'26862 =0 ... ... ... ... I76I6 5'4586 4 0'32271 ... ... 0'73130 0'23248 S=M+N ... I'6687 4'9644 I 0o33614 ... . . 0o658Io 0'28543 L. 0 ... ... . . 3'4596 9'5774 I 0'36124 3'4996 MNI K ... 8-'939 15'7398 0'52058 8'2736 * 2'5 sets taken on the first cday were very unsteady . The one taken on the second was close , and gave 1'0267 . t At the same time I tried two helices similar to A and B , except that their wire is varnished iron , which were given to me by Dr. Callan . Their ~4 is 0-6887 , and their spark only 0'524 in . The 4 of AB is 2-9138 times as great , a difference caused solely by the greater resistance of the iron . 1 . As before , two helices in series give no increase of quantity ; M+ N is the same as N , G+L nearly the mean of G and L. 2 . The quantity of collateral helices is seen in column 6 ( as in Table II . ) to be the sum of the separate actions of each . The discrepancies are not greater than what can be explained by the uncertainties inherent in these measures , which I have already described . One apparent exception is a strong confirmation of this.rule the case of G. H ( 1 + K ) . Its observed ( I=3'0552 , while the sum =4'6220 . G and I being on the same primary are excited together ; but in measuring either , as there is no current in the other ( but merely a state of tension ) , their n is not changed . When , however , they are connected collaterally , the currents react on each other , their [ I 's are increased : the V 's are thus diminished , and therefore their resultant is the sum of quantities less than those used in the computation . The b 's in this case become-for G 0'94289 , for H 0-79885 , and for I+ K 0'34588 , which are quite sufficient to account for the difference . 3 . As with I in Table II . , so here it will be observed that N has less relative power than either I or K ; its actual power is even less , though its theoretical force exceeds theirs in the proportion of 5 : 4 . This is explained by its b being so much smaller ; but it gives this important information , that , at least in helices of these dimensions , nothing is gained by using wire thicker than that of I , or of an inch* . 4 . The effect of L is far less than that of I+ K. In the first the helices are on the same primary , in the other on separate ones . In the former case the II is larger , for it is the sum of the [ 1 of each on itself , and those of each on the other ; b therefore is less . Besides , the potential of the core on the helices is less than when each of them is central on it . The difference is even more remarkable in O as compared to its elements M+N , its effect being only 0'7 of the other , and 0-3 of the theoretic power . The same disparity of course prevails in their combinations ; O. L giving only 3'46 , while the same four helices arranged on separate primaries give 8 ' 19 . The combinations G. H ( I+ K ) and G. L. H have the same helices ; but in the first two were on the same primaries . As , however , they were 1*5 inch instead of 0'5 apart , the [ I was not so much increased as in the other cases , and therefore there is not quite so great a decrease of power . The following practical maxims may be deduced from the experiments and reasoning whiph I have related . The attention of instrument-makers has been chiefly directed towards increasing the length of spark given by these machines , and in this they have succeeded to a surprising degree ; but in doing so they have not added to the quantity of electricity which is produced by them . This , however , is by far the most important object ; for in most applications of the inductorium all tension above what is necessary to force the necessary quantity of current through the circuit is useless , nay sometimes injurious* . I am inclined to think that a tension which gives sparks of 4 inches will be found quite sufficient in ordinary cases , and this will be given by about 20,000 spires ; all beyond only adding to the weight of the instrument , its cost , and the difficulty of insuring its insulation , It must be kept in mind that the mere quantity is independent of the length of wire : I actually found it the same for a flat spiral of 21 spires and for a helix of 13,655 . It is not , I believe , ascertained what is the best proportion of height and diameter for a secondary helix of a given number of spires . It is generally made as long as its primary , though perhaps not on any definite principle . The magnetic potential P is in this form a little greater than in that which I used , but so also is II : the length of wire is less , which increases F , but also decreases b ; and a priori it is not easy to decide which way the balance inclines . The I is something less if the spires be in separate sections than if they be in one continuous coil . The dimensions of the core do not seem to be of importance as to quantity within the limits which I tried ; their length seems to increase the tension . The quantity is greatly diminished when the rheotome works rapidly ; and in spectral work the probable limit of its slowness is that the impression on the eye shall be continuous . The quantity increases with the diameter of the wire up to a maximum , which is attained when this is about the sixty-fifth of an inch . Helices may be combined either for tension or quantity without much loss of these respective powerst . If for the first , they are combined in series ; the general tension is the sum of the individual ones , and in this way we can obtain sparks of a length limited only by the strength of the insulator which is interposed between the primary and secondary helices . If the latter be all of the same wire , the quantity remains unchanged ; if they differ in this respect , it will be intermediate between the weakest and strongest . If they are combined for quantity , they must be set collaterally , i. e. all their positive terminals connected , and all their negative . The resulting current will be the sum of all the separate ones , but the tension is not increased ; the sparks seem even a few hundredths of an inch shorter , but are much denser , and in the higher combinations approach to the character of a jar discharge . Hence there is no risk to the apparatus by extending this mode of combination to any extent . It deserves notice that the helices need not be equal in tension or resistance ; thus the arrangement G. K gives little less than the sum of its : components , though K has only half as many spires as G and but a tenth of its resistance . In combining these instruments , the primaries should not be consecutive if of large numbers , for so the action of their extra-current would be very destructive to the rheotome ; with P'+P"t containing 726 spires in series the spark in the mercurial one is almost explosive , but when they are collateral it works quietly . Were , however , ten or twelve to be so combined , it would require a battery of very large cells to maintain the current , and it is better to have a separate battery for each pair of primaries . In this I find no difficulty ; the negative* poles of all the batteries are connected with the mercury of the rheotome ; from its platinum point , separate wires go to the entering bind-screw of each primary , other wires go from their exit bind-screws to the positive poles of their respective batteries , and thus their action is perfectly simultaneous . Of course , if many batteries were used , the current in the rheotome might be too powerful , but then there would be no difficulty in having separate rheotomes worked by one electromagnet , and ( at least with the mercurial form ) adjusting them by a revolving mirror to perfect synchronism . In this way I feel sure that we can attain an amount of electric power which has not yet been approached by the inductorium , and which may be expected to be a most powerful means of research in those inquiries to which I referred at the commencement of this paper . At the head of these stands the palmary discovery of Mr. Huggins , that there are nebulae and comets whose matter possesses spectral attributes not corresponding to that of the sun , the stars , or our own earthly elements . Is that difference an indication of some body sui generis , or a mere result of peculiar temperature or other molecular conditions ? Is , for instance , the bright line , corresponding to one of nitrogen , which occurs , we may say , normally , produced by nitrogen as such ? If so , what has blotted out the other bright lines of that magnificent spectrum ? Is it due to an element of nitrogen , dissociated by some enormous temperature from other elements , perhaps from hydrogen , one line of which is also present ? And the third line , elsewhere unknown-is it the herald of a new body , or merely a derip vative from another spectrum ? We cannot even hope for an answer to these questions till the spectra of at least those elements which seem cosmical have been examined through a range of temperature extending from the lowest that developes in them luminous lines , to the highest that is excited by the most potent electric discharges which we can produce and control . Now , to obtain such a graduated range , the plan of combination which I have been describing seems well fitted . It , of course , cannot be expected to equal , under any extension , the wonderful voltaic battery of Mr. Gassiot ( at least its arc-discharge ) ; but how few can avail themselves X If the mercury be made positive , each discharge makes a sharp report and blows about the metal and alcohol in most unpleasant profusion . of such an instrument as that ! But if , as seems probable , we can without much difficulty increase the heating-power of the induction-discharge an hundredfold , we shall have made a very great step , and by means which are everywhere accessible . Inductoria are common ; there are few situations where a physicist cannot obtain access to several , and combine them as Despretz did the voltaic batteries of Paris to make the experiments which have thrown such splendour on his name .
112611
3701662
On the Stability of Domes
182
188
1,866
15
Proceedings of the Royal Society of London
E. Wyndham Tarn
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0041
null
proceedings
1,860
1,850
1,800
7
102
2,713
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112611
10.1098/rspl.1866.0041
http://www.jstor.org/stable/112611
null
null
Measurement
37.777237
Formulae
33.051722
Measurement
[ 57.832481384277344, -23.54616355895996 ]
IV . " On the Stability of Domes . " By E. WYND)HAM TARN , M.A. Communicated by GEORGE GODWIN , Esq. Received May 5 , 1866 . The few writers who have attempted to treat the subject of the Equilibrium of Domes mathematically , have entirely failed to obtain results that are of any practical use to the architect . Their failure has arisen from taking a too theoretical view of the subject , and endeavouring by mathematical reasoning to find the form which a dome ought to have in order that it might stand safely . Such a question is of no practical utility , as domes of various sizes and forms have been erected for centuries past , and the question for the architect is , -given a dome of certain form and size , what are the conditions which must obtain between it and the wall of the building it is intended to cover , in order that the whole structure may be in a condition of stability ? The object , therefore , of this paper is to find a solution to the following problem : Given a spherical dome , built of stone or brick , of any radius and thickness , and standing on a " drum " or walls of any height ; to find the thrust of the dome on the " drum , " and the thickness that must be given to the walls in order to insure the stability of the structure . I take the case of the dome having a spherical section , as being the form most commonly used ; but the same method of investigation will apply to domes of any form . In this investigation I shall consider the dome as made up of a large number of arched ribs , of which the bases resting on the top of the " drum " subtend a small angle ( 9 ) at the centre , and the vertices have no thickness ; each rib having the form of a wedge cut out of the spherical shell by two planes intersecting in a vertical line through the centre , and making the small angle 0 with each other . I shall then consider that the two wedges thus formed on opposite sides of the dome , thrust against each other at the vertex , as in the case of an ordinary semicircular arch , and by this means keep each other in equilibrium . Of course no arch of this form if built alone could stand for a moment , as it would give way laterally ; but in the dome this is prevented by the parts on each side of the rib under consideration . This method is adopted by Venturoli in treating on the equilibrium of domes . Fig. 1 represents a rib of the form above described cut out of the dome , and the corresponding part of the " drum " which sustains it . The arch will have a tendency to fall in at the crown C D , and open outwards at the haunches E F , causing the joint CD to open at D , and that at OF to open at F. We may therefore suppose that N , the thrust of the corresponding rib on the opposite side , acts at C. We shall now find the effect of the force N upon a given joint OF . Let P be the weight of the portion of rib above OF ; x the perpendicular distance from E of a vertical from the centre of gravity of P ; y the vertical distance of CN from E. Then the moments of these forces about E are Px and Ny ; and in order that there may be equilibrium , we must have N equal to the greatest value of P. e. We have therefore to express Px in gY terms of 0 , the angle which FE makes with the vertical , and find what value of 0 makes Pa maximum . Let r be the internal and R the external radius of the sphere , 8 the weight of a cubic foot of the material of which it is composed . Then the volume of any portion of the rib ( p qrs CD ) is V= ! fsinO.de.dr . ; ... ... ... ( A ) so that P= . V=3 . q ( 1 -cos 0 ) R 7 , taking limits from 0=0 . 3§ 1866 . ] 183 Ifgis the centre of gravity of the portion of the rib whose weight is P , and G its projection on OA ; then if OG=z , we find the value of z from =SSSr3 . sin 0 . cos. dr . d. dp SSSr2 . sin 0 . d. dO sinl SSr3 ( 1-cos 20 ) dr. . d --3 ' g.r2..sin 0 . dr . dO( And since q is small , we may consider 1 --_ , nearly ; in which case 3 R4--r40sin 20 81 3-r 1-coso Now x is the perpendicular distance of gG from E ; therefore --=r sin 0 . R-3 3 O-I-r4 -sin 20 Therefore Px=.p ( 1 -cos 0 ) t rsin 0R4-sin 20 3X 8t_r-r l-cos0 J or PxJ 8r ( R3-r3 ) sin0 ( 1 -cos 0)-3 ( R4-r4 ) ( 0-I sin 20 ) . And since y=R-1r cos 0 , and Np - , y N. 8r ( R3-r3 ) sin 0(1-cos 0)-3 ( R4--r ' ) ( 0-sin 20 ) 24 R-r cos 0I will take q as the circular measure of an angle of 2 ? , or -7r ='0349066 , in which case we have N= 001454 Sr(R3-r3 ) sin 0 ( 1 -cos 0)-3 ( R4--4 ) ( 0-sin 20 ) R1-r cos 0 ='001454 x N ' , say . We have now to find what value of 0 will make N ' a maximum , and as the ordinary rules for maxima will not apply to this expression , we must find it by calculating N ' for different values of 0 . I have done this for the case when r2 10 , R= 11 , and find that N is greatest when 0= 70 ? ; thus 0=69 ? ... ... . -506'034 0=70 ? ... ... ... . N'=506-241 071 ... ... ... . N'=506-018 . We have now to substitute in N the values of 0 , sin 0 , &c. when the angle is 70 ? , or when 0=35 9= '22173 , sin 0=-93969 , cos 0= 34202 , sin 20 90 = '64279 . This reduces the expression for N to N=_ 007192r ( I3--r)-0039273 ( Rl-r4 ) --4 t02 We can now transpose N and P to the point E ; and in order to find the thickness of the pier , we proceed to take their moments , together with those of the part of the rib below OF , and the pier itself , about the outer bottom edge S of the pier . If we call yS= b , the perpendicular distance from S of the direction of N , then b=H+r.cos0 , ... . . ( 2 ) where I is the height RS of the pier or " drum . " Let Se=a , the distance from S of a vertical dropped from E ; F=the weight of the portion of the rib below OF ; c=the perpendicular distance from S of a vertical from the centre of gravity of the lower portion of the rib whose weight is F ; Q=the weight of the portion of the " drum " on which the rib stands , and q=the distance from S of a vertical from its centre of gravity ; we have then ( in equilibrium ) the equation N.b=P.a+Q.q+F.c , ... . . ( 3 ) which I will call the Equation for Equilibrium . From this equation we can find the thickness ( t ) of the pier necessary to produce equilibrium . In order , however , that we may have stability in the structure , we must multiply Nb by the coeffcient of stability , which we may take as 2 . The equation from which to find the value of t then becomes 2N . b=P.a+Q.q+F . c , ... ... ( 4 ) which I will call the Equation of Stability . I now proceed to find the values of P. a , Q. q , and F. c. The value of P was previously found to be P=B . 1-cosO ) R--r ; and if we substitute for q and 0 their values , P= -007656 ( R3-r3 ) . Also a=Se=t+r(l-sin 0)=t+'06031 r ; so that we find for the value of P. a , Pa= 007656 6 ( R3-3 ) t+ 0004618 a. ( R3-r3 ) ... . ( 5 ) The value of F is found by means of the integral ( A ) , taking the limits from 0=0 to 0=-- ; which gives us 3__ -r3 F=B..cos O3r ==00398 a ( R3r ) . Let z1 be the distance from O on OA of the perpendicular dropped from the centre of gravity of the portion of the rib whose weight is F. Then the integral ( B ) gives us , by taking the same limits of 0 as for F , --O+ sin201 3 R4 r4 220 18 lt3-r3 cos 02 And if we substitute for 0 its value , RI4 _r4 z=-*7351 a And c=OR-z1=-t+r-- , . Hence we find F. c= -00398 a ( R3-r3 ) t+ 00398 3 { r ( R3-r3)-7351 ( R4-r4 ) } . ( 6 ) We have now to find the moment about S of the weight of the pier . Let Q be the weight of the pier , a , the weight of a cubic foot of its material ; then Q= ? . 1 ( ( r+ t)2-r2 ) . H= ( 2r+t ) t. H =-017453 a ( 2r +-t ) t. H. Let figure 2 represent the plan of the pier , g its centre of gravity , ST=t its thickness . Then by the integral calculus we find 4 ( r+ t)-3 r3 sin ? 0 sin ? I_ O3( +)2X7 ; or putting =3 ( r $t)2 _ r2 72 _2 ( r+ t)3-r__2 ( 3'+ 3 ? t+ t2 ) . 3 ( 2.+ t)2-.2 3 ( 2r+ t ) q=Sg-=OS-Og=r+ t-Og =3 ( rt ) ( 2r+t)-2 ( 3r2+3rt+ t2 ) 3 ( 2r-+ t ) 3rt + t2 3 ( 2r+t ) We therefore obtain for the value of Qq , Qq=-017453 1(2r+ t ) t. 3r+ tt 3 ( 2r ? t ) =*0058177 . t2 ( 3r+ t ) ... H. ( 7 ) We can now , by adding together the several quantities ( 5 ) , ( 6 ) , ( 7 ) , and equating to the value of N6 as found from ( 1 ) and ( 2 ) , form the equation for equilibrium ( 3 ) , which will be a cubic equation in respect of t. We shall thence find the value of t necessary to produce equilibriumm in the structure , and , by equating the same quantities to 2Nb , form the equation for stability ( 4 ) , from which we get the value of t necessary to produce stability in the structure . The following examples will serve to show how readily these formulm can be applied , and the use which the practical architect may make of them . Example 1:Let r= 10 ft. , R=1 ft. , -= 125 lbs. , = 150 lbs. , H= 50 ft. From ( 1 ) ... N= 920092 ; , ( 2 ) ... b= 53-4202 ; therefore Nb =4915 , and 2Nb =9830 . From ( 5 ) ... P.a= 316-767 t +191-06975 ; , , ( 6 ) ... F. c= 164-6725 t-5054 ; , ( 7). . Q.q= 1308-98 t2+ 43-63275 t. Hence the equation for equilibrium ( 3 ) is 4915=43-63275 t3+ 1308-98 t2 481 4395 t+ 14052975 , which reduces to t3 + 30t2-+1 103t--109'42-0 . We can solve this by means of Horner 's process , and find t= 1-7 ft. for equilibrium . The equation for stability ( 4 ) becomes 9830=43-63275t3+ 1308-98t2+481 4395t 4140'52975 , which reduces to 430t2+1 103t-222-069=0 , from which we obtain , by Homer 's process , t=2'45 ft. for stability . Example 2:Let r=30 ft. , R=33 ft. , H=80 ft. , 6 and a , as before . From(1 ) ... N= 2483-84 ; , ( 2). . b= 90-2606 ; therefore Nb =224192-8 , and 2Nb =448385-6 . From ( 5 ) ... P. a= 8552-71 t+415476-65 ; , , ( 6 ) ... F.c= 4446-16 t+ 4094-17 ; ( 7 ) ... Q.q= 69-8124t3+ 6283-116t2 . Adding and reducing , the equation for equilibrium becomes t3 +90t2+ 186'2t-3048-31 =0 , whence t=4-83 ft. for equilibrium . And the equation for stability is t3+ 90t2 + 186-2t-6159'7=0 , whence t=7-07 ft. for stability . Example 3:I will apply the formulae to the case of the dome of Sultan Mohammed 's tomb at Beejapore , described in Mr. Fergusson 's 'Handbook of Architecture . ' One peculiarity of this structure is that the inner face of the dome is set 5 ft. 6 in . within the inner face of the wall on which it rests , as shown in fig. 3 . ; so that in calculating the values of a , &c. , we must add 5-5 ft. to the thickness t ; hence we shall get a proportionately less value for t from the resulting equations . In this dome , r=62 ft. , R=72 ft. , H=-=116 ft. ; and we will suppose , as before , that 3=125 lbs. , -=150 lbs. From ( 1 ) ... . N= 31132 ; , , ( 2). . b= 137-20524 ; therefore Nb =4271473-522 , and 2Nb =8542947-044 . From ( 5). . P. =957 ( 134920 ) ( t +55)+3-56745 ( 134920 ) =129118'44 t+1191511-78 ; ( 6). . F. c=-4975 ( 134920 ) ( t+5 5)--4975 ( 527854-4 ) =671227t + 106567-28 ; , , ( 7 ) ... Q.=10122798 3+186xl 01 22798t2 . Adding and reducing , the equation for equilibrium ( 3 ) becomes t3+ 186+t2 1938-6t-29373-24=0 , whence t=8-2 ft. for equilibrium . And the equation for stability ( 4 ) becomes t3+ 186t2+ 1938'6t-71570=0 , whence t= 14-66 ft. for stability . In the construction of this particular dome , the values obtained above for t will only apply to four points on the walls which carry the dome ; for instead of being built on a circular " drum , " this drum is made to cover a square chamber by means of " pendentives , " which are so arranged as to throw the thrust principally on the angles of the building , where the values of a and c will become very great , and it is only at the centre of each of the four sides that the above equations can be employed to compare the thrust of the dome with the strength of the walls . At these four points the walls are about 11 ft. thick , so as to be considerably more than sufficient to produce equilibrium ; and the coefficient of stability at these points is 1-374 instead of 2 . Had the dome therefore been built on a circular drum of 11 feet thickness , in all probability the edifice would not have stood for any length of time . Much of the thrust of a dome may be counteracted by means of an iron belt placed round it at the point where the thrust is greatest . This point I have shown to be at 70 ? from the crown , or 20 ? from the springing .
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12
261
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Neurology
53.631414
Optics
22.630601
Neurology
[ -74.5524673461914, 13.948366165161133 ]
I. " On the Anatomy of the Fovea centralis of the Human Retina . " By J. W. HULKE , F.R.C.S. , Assistant Surgeon to the Middlesex and Royal London Ophthalmic Hospitals . Communicated by WM . BOWMAN , Esq. Received May 26 , 1866 . ( Abstract ) . 1 . The Fovea centralis is a minute circular pit in the inner surface of the retina , made by the radial divergence of the cone-fibres from a central point , by the thinning and the outward curving of the inner retinal layers towards this point , and by the peripheral location of the outer granules belonging to the central cones . 2 . The inner surface of the retina declines in a rapid uniform curve from the edge to the centre of the fovea , and very gradually from the edge towards the ora retine ; so that the edge of the fovea is the most raised part in the macula lutea , where the retina is thickest , and the centre of the fovea the most depressed part in the macula , where the retina is thinnest . 3 . At the centre of the fovea , proceeding from the outer to the inner surface of the retina , we meet with the following structures in succession:the bacillary layer and the outer limiting membrane , a small quantity of finely areolated connective tissue , the inner granule-layer and the ganglionic layer very attenuated , a thin granular band containing optic nerve-fibres , and the membrana limitans interna . 189
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On the Anatomy of the Fovea Centralis of the Human Retina. [Abstract]
189
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1,866
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Proceedings of the Royal Society of London
J. W. Hulke
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1,661
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108,970
Neurology
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Biology 3
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Neurology
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I. " On the Anatomy of the Fovea centralis of the Human Retina . " By J. W. HULKE , F.R.C.S. , Assistant Surgeon to the Middlesex and Royal London Ophthalmic Hospitals . Communicated by WM . BOWMAN , Esq. Received May 26 , 1866 . ( Abstract ) . 1 . The Fovea centralis is a minute circular pit in the inner surface of the retina , made by the radial divergence of the cone-fibres from a central point , by the thinning and the outward curving of the inner retinal layers towards this point , and by the peripheral location of the outer granules belonging to the central cones . 2 . The inner surface of the retina declines in a rapid uniform curve from the edge to the centre of the fovea , and very gradually from the edge towards the ora retine ; so that the edge of the fovea is the most raised part in the macula lutea , where the retina is thickest , and the centre of the fovea the most depressed part in the macula , where the retina is thinnest . 3 . At the centre of the fovea , proceeding from the outer to the inner surface of the retina , we meet with the following structures in succession:the bacillary layer and the outer limiting membrane , a small quantity of finely areolated connective tissue , the inner granule-layer and the ganglionic layer very attenuated , a thin granular band containing optic nerve-fibres , and the membrana limitans interna . 189 4 . The bacillary layer contains only cones in the fovea , but rods in addition towards the periphery of the macula lutea . 5 . The cones and rods in the macula are longer and more slender than at a distance from it . Although the greater slenderness is more apparent in the cones , yet the most slender cones are stouter than the rods . 6 . In both cones and rods an inner and an outer segment are discernible , and both segments consist of a sheathing membrane and contents . In the outer segment the contents do not exhibit any indication of structure . The inner segment , where its dimensions permit , contains an " outer granule , " and is always produced in the form of a fibre , which connects the cones and rods with the inner layers . These I have called the primitive coneand rod-fibres , collectively primitive bacillary fibres . ( K6lliker , in the last edition of his ' Handbuch der Gewebelehre , ' restricts to these the term " Miller'sfibres , " which was originally exclusively , and is still very generally given to the vertically radial connectivetissue fibres first described by H. Miuller . ) 7 . An outer granule is intercalated in each primitive bacillary fibre , 1st , where the inner bacillary segment is too slender to include the granule , and , 2nd , where the segment is associated with a distant granule . This kind of connexion always obtains with the rods , and with the cones at the centre of the fovea . The outer granules which belong to the rods are not distinguished from those which belong to the cones by any constant characters . 8 . The primitive bacillary fibres run obliquely from the outer towards the inner surface of the retina , and radially from the centre of the fovea towards the periphery of the macula lutea . 9 . They form a very conspicuous obliquely fibrillated band , lying between the outer and the inner granule-layers , in which the primitive fibres combine in bundles which have a plexiform arrangement . This band corresponds to that band which in the chameleon 's retina I called the conefibre plexus . Muiller and K6lliker call it the intergranule-layer . 10 . Between the inner surface of this layer and the inner granule-layer , there is a thin granular band of finely areolated connective tissue , through which the bacillary fibres pass into the inner granule-layer . It is in part derived from the terminal divisions of the vertically radial connective-tissue fibres , and it answers to the band which in the chameleon I termed the intergranule-layer . 11 . In the inner granule-layer two kinds of granules are distinguishable , nuclei and nucleated cells . Both are in connexion with the oblique bacillary fibres , which in this situation are exceedingly delicate , and require a high magnifying power and a good section for their demonstration . 12 . The connective-tissue fibres ( generally known as Muller 's radial fibres ) , which traverse the retina in a vertically radial direction from the membrana limitans interna towards the outer surface , are very conspicuous in the inner layers , where in sections transverse to the direction of the optic nerve-fibres they are arranged in arcades , which contain the lastnamed fibres and the ganglion-cells imbedded in a granular matrix of finely woven connective tissue . They are less visible in the outer layers , apparently because many of their terminal divisions lose themselves in the ( connective tissue ) intergranule-layer ; and hence the decussation of the oblique bacillary and the vertically radial connective-tissue fibres within the cone-fibre plexus , so conspicuous in the chameleon , is scarcely noticeable in the human retina . Deductions . 1 . Since the total of the effects of light upon living tissue will be greater as the extent of tissue traversed by it is greater , and since the relative common sensitiveness of a surface varies with the number of distinct sentient elements it contains , it follows that the greater length of the cones and rods , and their greater slenderness , which allows a larger number of them to the superficial unit , are in harmony with the greater sensitiveness of the retina at the macula lutea . Inasmuch , however , as the foveal cones are stouter than the rods , a superficial unit at the centre of the fovea contains fewer sentient ( i.e. percipient ) elements than the same unit near the periphery of the macula lutea ; and on this ground the sensitiveness of the retina at the fovea should be less than that of the retina near the periphery of the macula . On the other hand , the extreme thinness of the inner layers of the retina at the centre of the fovea , places the bacillary layer here most favourably for receiving incident light . 2 . The division of the rods and cones into an outer and an inner segment is natural . The facts in support of this are , the presence of the division in perfectly fresh specimens ; its sharpness and constant occurrence at a definite place ; the constantly rectilinear figure of the outer , and the curvilinear figure of the inner segment ; the different refractive powers of the segments ; and their different behaviour towards staining and chemical solutions . 3 . From these structural differences it is a fair inference that the segments have different physiological meanings . The higher refractive power , straight sides , and slender cylindrical or prismatic figure of the outer segment may be adaptations for confining within the segment light incident upon its ends , and for preventing the lateral escape of light through the sides of the segment into neighbouring cones and rods . These considerations incline me to adopt the opinion that this segment has an optical function , an opinion which derives further support from the fact that , in those animals in which the segment is so wide a cylinder that a ray might be incident upon the inner surface of its sides at a small enough angle not to be reflected but to pass out , the segment is insulated by a sheath of black pigment . The inner segments of the cones and rods are the specially modified peripheral terminations of the optic nerve-fibres ; and at their junction with the outer segment the conversion of light into nerve-force may take place . 4 . The outer granules being the nuclei of the inner coneand rod-segments , probably maintain the integrity of these as living tissues , and are not directly concerned in their specific functions as organs of perception . 5 . The primitive bacillary fibres are the link by which the cones and rods communn icate through the inner granules and ganglion-cells with the optic nerve-fibres . 6 . The smaller inner granules are nuclei of the oblique bacillary fibres in the inner granule-layer ; or they may be small bipolar ganglion-cells , and act specifically on the forces transmitted through the oblique fibres from the cones and rods . The larger inner granules not being distinguishable by any definite structural characters from the smaller cells of the ganglionic layer , may agree with these latter cells in function . 7 . Since the ganglion-cells ( of the ganglionic layer ) are fewer than the inner granules , and much fewer than the cones and rods , and since it is probable that these latter communicate with the optic nerve-fibres only through the ganglion-cells , it follows that one ganglion-cell probably is in correspondence with more than one inner granule and with several cones and rods . From this it is not an improbable conjecture that the cones and rods are disposed in groups , each of which is represented by one or more ganglion-cells thef unction of which is to connect or coordinate the individual action of the separate bacillary elements in their groups . in a manner analogous to that attributed to the ganglion-cells of the spinal cord by Van der Kolk* . 8 . There is a close general resemblance between the human fovea and that of the chameleon t.
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Second Memoir 'On Plane Stigmatics.' [Abstract]
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Proceedings of the Royal Society of London
Alexander J. Ellis
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Formulae
86.043532
Optics
7.482235
Mathematics
[ 66.26078796386719, -26.250749588012695 ]
II . Second Memoir " On Plane Stigmatics . " By ALEXANDER J. ELLIS , F.R.S. , F.C.P.S. Received May 26 , 1866 . ( Abstract . ) Let there be two groups of points upon a plane , termed , for distinction , indices and stigmata respectively , bearing such relations to each other that any one index determines the position of n stigmata , and any one stigma determines the position of m indices . The theory of these relations between indices and stigmata constitutes plane stigmatics . Each related pair of index X and stigma Y constitutes a stigmatic point , henceforth written " the s. point ( xy ) . " The straight lines joining any index with each of its corresponding stigmata are termed ordinates . If , when I have an impression that I have seen this in a German author , but have not been able to find the passage again . t H. Miller , " IUeber das Auge des Chamaleon , " Wurzb . naturw . Zeitschr . Bd . iii . S. 36 . the index moves upon a straight line , the ordinate remains parallel to some other straight line , the relation between index and stigma is that expressed by the relation between abscissa and ordinate in the coordinate geometry of Descartes . When only one index corresponds to one stigma and conversely , and both indices and stigmata lie always on one and the same straight line , or the indices upon one and the stigmata upon another , the relations between indices and stigmata are those between homologous points in the homographic geometry of Chasles . The general expression of the stigmatic relation is obtained by a generalization of Chasles 's fundamental lemma in his theory of characteristics ( Comptes Rendus , June 27 , 1864 , vol. lviii . p. 1175 ) , clinants being substituted for scalars* . It results that in certain forms of the law of coordination , which " coordinates " the stigmata with the indices , there may be solitary indices which have no corresponding stigmata , and solitary stigmata which have no corresponding indices , and also double points in which the index coincides with its stigma ( 76)t . The particular case in which one index corresponds to one stigma and conversely , and no solitary index or stigma occurs , is termed a stigmatic line ( henceforth written " s. line " ) , because the Cartesian case is that of a Cartesian straight line in ordinary . coordinate geometry , but in the general s. line the figures described by index and stigma may be any directly similar plane figures ( 77 ) . The investigation of this particular case occupies almost the whole of the Introductory Memoir . When one index corresponds to one stigma and conversely , but there is one solitary index and one solitary stigma , we have s. homography , provided the solitary index is distinct from the solitary stigma ( 79 ) , and s. involution when the solitary index coincides with tl e solitary stigma ( 78 ) , so called because they generalize the relations treated of under these names by Chasles . When the relations between index and stigma are expressed by an equation of the second order , the s. curves are termed s. conics , because they include Cartesian conics as a particular case ( 80 ) . Generally two stigmata correspond to each index , and two indices to each stigma , and there is no solitary index or stigma . Two s. curves in.tersect when they have a common ordinate , and there* If 01 be any fixed axis of reference , and AB any line upon a fixed plane passing through OI , we may consider that a line equal in magnitude and direction to AB can be formed from OI by the operation of turning OI through the Z ( OI , AB ) , and altering its length in the ratio of the length of 01 to that of AB . When all such lines AB lie upon the same plane , this operation is termed a clinant and represented by ab to distinguish it from the line AB . If the lines AB lay on different planes , the operation would be in general a quaternion . But if AB is parallel to 01 , whatever be the plane on which it lies , the operation ab is termed a scalar . Clinants and scalars obey the laws of ordinary commutative algebra . Quaternions do not . t The figures in parentheses refer to the articles of this " Second Memoir , " which are numbered consecutively to those in the Introductory Memoir ( Proceedings , April 6 , li)5 , vol. xiv . p. 176 ) . 1866 . ] 193 fore a common s. point . They touch when a slight alteration in the constants of one equation will make one of their common s. points into several , having their stigmata very near . When they have no common ordinate or s. point , they are parallel or asymptotic , according as the distances between the stigmata corresponding to a common index remain unchanged or , under certain circumstances , diminish infinitely ( 81 ) . It has been shown in the Introductory MVemoir that a s. line can be determined by two stigmata corresponding to known indices , or by two points called the direction-point and original stigma* . Taking either the two first-named or the two last-named points as the index and stigma in a stigmatic relation , we are able to make its expression denote a linear relation , which leads to the conception of enveloped s. curves , and therefore of classes of s. curves ( 82 , 83 ) . In the above relations two ordinary geometrical points ( " g. points " ) in a plane form the index and stigma . If we now take two s. points ( that is , two relations of index to stigma ) , terming one primary and the other secondary , we are able , by means of two equations , to express a relation between these s. points , so that one primary shall correspond to n secondaries , and one secondary to m primaries . This is the bipunctual relation ( 84 ) , and includes the whole subject of related s. curves , of which related Cartesian curves form a particular case . The most important and elementary cases are , first , those in which the related s. points lie respectively on known s. lines , s. involutions , s. homographies , or s. circles , and there is a stigmatic relation between the stigmata considered as forming two groups , one of indices and one of stigmata ; and secondly , those in which one primary s. point corresponds to one secondary and conversely . In the latter case the relations between one index and stigma may be inferred from known relations between another index and stigma , or from the same index and a new stigma , or , as is most usual , from the same stigma and a new index . Hence follows the general theory of change of coordination ( 85 ) . Homographic and homologic s. figures ( b6 ) are another example , in which one primary corresponds to one secondary s. point and conversely ; but there is generally one solitary s. line in aach s. figure such that no s. point taken upon it will have any corresponding s. point in the other figure . Corresponding to the bipunctual relation there is a bilinear relation ( 87 ) in which one primary s. line corresponds to several secondary s. lines , and one secondary to several primaries , by means of the elements chosen to represent linear relations . To this belongs the biradial relation ( 87 b ) , where two pencils of s. rays , being drawn from known s. points , are determined generally by s. points having a bipunctual relation , and exceptionally by their direction-points only , so that the relation between the rays can be expressed by a stigmatic relation between the direction-points considered as indices and stigmata . When this s. relation between the directionpoints is a s. homography , we have pencils of homographic s. rays . The reciprocal relation , in which a s. point corresponds to several s. lines , and a s. line to several s. points , follows immediately ( 88 ) . Finally , the multindicial relation ( 89 ) shows how several indices may be made to correspond as one group to a single stigma or a group of stigmata , and thus leads to the geometrical expression of the algebraical theories of several independent variables . The means by which a theory of solid stigmatics , where the indices and stigmata are taken anywhere in space , may be expressed by quaternion equations is briefly pointed out ( 89 e ) . The systematic explanation and precise expression for all these relations , together with some convenient notations relating especially to s. angles * ( 90 ) , and to anharmonic ratios ( 91 ) , occupy the first part of the present memoir . The remaining two divisions are devoted to a somewhat fuller consideration of s. homography ( including s. involution ) and s. conics . It results ( 92 ) from the conception of s. involution , already givein , that if S be the coincident solitary index and solitary stigma , and X , Ya corresponding pair of index and stigma , that is , if ( xy ) is a s. point on the s. involution , there will be two points , E , F ( called double stigmata ) , in the same straight line with S , in which index and stigma coincide , forming the double points ( ee ) , ( ff ) , and then seS=sf2=sx.sy , which implies that Z XSE =L ESY , and Z XSF =Z FSY , and also that each of the lengths of SE , SF is a mean proportional between the lengths of SX and SY . It is readily shown that the two cases of involution of points in a line , usually acknowledged , are but the particular cases of XY lying on the line OF , or on a line through S perpendicular to OF . In the former case the double points lying on the line containing XY were readily found , and hence termed " real ; " in the latter , as the method of investigation did not suffice to determine the double points , they were termed " imaginary . " If A , B , C , D be any four indices , and A ' , B ' , C ' , D ' their corresponding stigmata in a s. involution , then ab . cd a'b ' . c 'd ' ab . cc ' a ' ' . c'c and - ; -T = _ , ad . cb = ad ' c'b " ac ' cb a'c . c'bb that is , the anharmonic ratiot of any four indices is the same as that of their corresponding four stigmata , and the anharmonic ratio of any three indices and stigma is the same as that of the corresponding three stigmata and index in a s. involution . If the index move on the characteristic circle whose centre is S and radius SE , the corresponding stigma moves in the opposite segment of the same circle , and in an opposite direction of rotation . Generally if the index move on any circle passing through E , F , the stigma moves on the segment of the same circle lying on the other side.of OF , and in the opposite direction of rotation . If the index moves on a straight line passing through S , the stigma moves on another straight line also passing through S. If the index move on a straight line not passing through S , the stigma moves on a circle passing through S and conversely . If the index moves on a circle not passing through S , the stigma moves on another circle also not passing through S , and in an opposite direction of rotation . If the whole group of stigmata be removed without disturbing their mutual relations , and so that the solitary index S no longer corresponds with the solitary stigma Z ' , a s. homography results ( 93 ) , in which the relations of index and stigma may be deduced from those in a s. involution . These relations are expressed by the equation s. z'y = sa . z'a ' , where ( xy ) , ( aa ' ) are s. points in the s. homography . When three s. points are given , the solitary index S , and solitary stigma Z ' , and double stigmata E , F can be determined by an elementary geometrical construction in all cases . These double stigmata possess important anqgular properties with respect to the indices and stigmata of the system ( 94 ) . Let ( aa ' ) , ( bb ' ) , ( cc ' ) be any three s. points in a s. homography . Then if ABC , A'B'C ' are straight lines ( in which case the former contains S , and the latter Z ' ) , tan AEA'= tan BEB ' ; that is , if two intersecting straight lines EA , EA ' revolve about their point of intersection E , and cut two given straight lines AB , A'B ' , determining an index A upon one , and a stigma A ' upon the other , so that the ordinate AA ' is seen under an angle whose tangent is constant* , the s. points will form part of a s. homography , of which the given point E is one double stigma , the solitary index S lying upon the index line AB , and the solitary stigma Z ' upon the stigma line A'B ' . If 0 be the middle point of SZ ' and F the other double stigma , FO=OE . If the two lines AB , A'B ' coalesce , then the two points E , F , fromw which the ordinates AA ' , BB ' , CC ' of three or more s. points , of which both indices and stigmata lie upon one straight line , are seen under an angle whose tangent is constant , are the double stigmata of the s. homography determined by these three s. points . This shows the nature of the points named in G. S. 171 t , and completes it , so far as " real rays " are concerned . It is further generalized hereafter . The two lines AB , A'B ' may be so placed that the s. homography has only one ( louble stigma O coinciding with the middle point of SZ ' , and O will then be the centre of a circle of which AB , A'B ' are tangents ; the ordinates of the s. points in the s. homography ( each of which contains an index and a stigma ) will then be tangents to the circle of which the centre ( being a double stigma ) will also contain an index and stigma . Hence is immediately obtained the relation in G. S. 664 , and an explanation of the remark there made , that " le centre du cercle tient lieu en quelque sort d'une tangente . " The tangent of the angle subtended by an ordinate at the double stigma may be constantly zero , that is , the ordinates may converge to the double stigma . Then , if through any point E two straight lines be drawn , and through any other point F rays be drawn intersecting the first line in a series of indices A , B , C , and the second in a series of stigmata A ' , B ' , C ' respectively , the resulting s. points ( aa ' ) , ( bb ' ) , ( cc ' ) willform part of a s. homography of which E , F are the double stigmata . This shows the nature of the points of issue and intersection in the fundamental proposition of anharmonic ratios , G. S. 14 , and completes it so far as " real " rays are concerned . It will be further generalized hereafter . Hence ABB'A ' is a quadrilateral , of which E , F are the intersections of opposite sides . Consequently if A , B ' and A ' , B are opposite vertices of a quadrilateral , and E , F the intersections of the opposite sides ( ab ' ) , ( a'b ) , ( of ) are s. points in a s. involution . This completes G. S. 350 , for " real " rays * . The above considerations determine all the relations of s. homography , but do not suffice to give an explanation of those " imaginary " rays which play so important a part in Chasles 's geometry . The requisite theory is very simply obtained by considering the direction-points of two sets of ( primary and secondary ) s. rays as indices and stigmata in a s. homography or s. involution ( 95 ) . In particular it is shown that if the s. tangent of the s. angle between two primary s. rays is equal to that between the two corresponding secondary s. rays , there are two pairs of parallel s. rays , which are parallel to the asymptotes of a s. circle ; and all the other relations for pencils of ordinary homographic rays are similarly generalized . In this case , if the direction-points of all the rays lie upon the same straight line passing through the origin , the s. rays correspond to those usually termed " real ; " and if any do not , the s. rays belong to the class usually termed " imaginary , " and were supposed not to have any geometrical existence . When the two s. points of issue of the two pencils are distinct , there will be generally two primary rays which are parallel to their secondaries ; and if the two s. points of issue coincide ( 96 ) , these parallel rays will become double rays . Both are found by finding the double points of the homography of direction-points . When the double rays are s. perpendicular* , the sum or difference of the s. tangents of the two s. angles made by the primary and its corresponding secondary with the double rays will be zero . If the direction-points form a s. involution , the s. rays form an involution , and there will be always two s. rays s. perpendicular and easily constructed . The stigmata of the s. points in which the primary and secondary s. rays of two pencils , making the s. tangent of the s. angle between such rays constant , intersect two given s. lines , are indices and stigmata respectively of s. points in a s. homography , of which the stigma of the point of issue is a double stigma ( 97 ) . Whence it follows that , in any s. homography , if the indices be considered as the stigmata of s. points on a known s. line , and the stigmata as the stigmata of s. points on some other known s. line , and a second index be given to one of the double stigmata so as to form a s , point which shall lie upon neither of those given s. lines , and pairs of s. rays be drawn from the s. point thus formed to pairs of corresponding s. points in the two s. lines , the s. tangent of the s. angle between any two corresponding rays will be constant . Supposing each primary s. ray to coincide with its secondary , and OI to be the axis of reference ( 98 ) , the stigma of the s. point of issue of a pencil of s. rays , and the stigmata of the intersection of these s. rays with a given s. line , form the indices , and the extremity I of the axis of reference OI , and the direction-points of the same s. rays , respectively form the stigmata of a series of s. points in a s. homography . Whence it follows that the anharmonic ratio of any four stigmata of intersection is the same as that of the four corresponding direction-points . This completely generalizes the fundamental proposition of anharmonic ratios , including the case where all the lines are " imaginary , " and can be made the starting-point of a series of propositions precisely analogous to those in G. S. , but with a much wider signification . Thus the property of the complete quadrilateral shows , on being generalized , that if E , A , B , C , D , Et , A ' , B ' be any eight points upon a plane , and two other points C ' , D ' be assumed so that the triangles E'A'C ' , E'B'D ' shall be directly similar to the triangles EAC , EBD respectively , and then two additional points F ' , F be determined so that the triangles FA'B ' , F'C'D ' shall be directly similar to the triangles FAB , FCD , the point F will be constant , if the first five points E , A , B , C , D remain unchanged , whatever the next three , E ' , A ' , B ' , may be , and will lie so that if SM be drawn bisecting the angles ASD , BSC and in length a mean proportional between the lengths of SA , SD , and also of SB , SC , then SM will also bisect the angle ESF , and be in length a mean proportional between SE and SF . When pairs of separate s. rays cutting one s. line are considered , it is shown ( 99 ) that if from any point pairs of ordinary rays be drawn which are the two limbs of a constant angle cutting any straight line in points forming the indices and stigmata of s. points in a s. homography of which the point of issue is a double stigma , and we furnish all the points lying on the given straight line , and the point of issue , with Cartesian indices , and hence consider all the s. rays as Cartesian , they willform part of an homography of s. rays , of which the double rays drawn from the Cartesian point of issue will be two non-Cartesian s. lines parallel to the asymptotes of a s. circle , and therefore independent of the magnitude of the constant angle . This furnishes a complete geometrical explanation of G. S. 171 , 172 , 181 , 651 , S.C. 293 , &c. Generally the whole of the propositions in G. S. respecting the homography of ordinary points and rays may be transferred to the homography of the stigmata of s. points and of s. rays , forming a series of propositions of much greater generality , in which all the s. points and s. rays will be perfectly real , and can be constructed by means of elementary geometry . The last division of this memoir is devoted to s. conics , which embrace the ordinary Cartesian conics as particular cases , together with all their so-called " imaginary " points and lines . The general equation is assumed ( 100 ) in the form or . 2o + 2o 3 . ox.oy +o . oy2+2o . ox+2 2oe . oy + o= 0 ; . ( a ) and it is shown that if of'= oa . oy the equation may represent a single s. line , or two parallel s. lines , or a s. acentric , which , by changing the origin and index , may be made to depend on the equation x'y2=4s'o ' . o ' ' ; but if oj32 is not = oa . oy , the equation may represent two intersecting s. lines , or a s. centric-that is , a s. curve which when cut by any s. line passing through a given s. point ( the s. centre ) has the index and stigma of that s. point in the middle of the lines joining the two indices and two stigmata of the s. points of intersection respectively . ' It is also shown that if the origin and index are changed , the s. centric may be represented by the equations 2+ y= l , or o'x " . x"oy = o. ( b ) 0 e2 0O(2 in which case the s. lines ox'= O , x'y 0 are indeterminate , but form pairs ofs . rays in involution , which are all conjugate diametrics* , with the exception of the double rays o'"=0 , x"y =0 , which are asymptotes . In the particular case that o =-0 , the general equation can , by changing origin and index , be made to depend on the equation ox'2-x'y2= o'e2 . Such curves are called s. cyclics . In the cyclic proper , the values of ot3 , oy may be any whatever ; in the s. circle o+ oy =0 , in which case all the conjugate diametrics are s. perpendicular , and the direction-points of the asy ptotes are I , I ' . But if both oa and ox become = 0 , the s. cyclic is a s. homography or s. involution . The general homographic properties of all s. conics are then deduced ( 101 ) . First , a s. conic is the locus of the s. points of intersection of the primary and secondary s. rays of two pencils of homographic s. rays with different s. points of issue , and passes through these points , which , with slight modifications , holds when a band of parallel s. lines is substituted for either or both of the pencils . Secondly , the anharmonic ratio of four s. chords in a s. conic drawnfrom a variable s. point tofour fixed s. points , bears a constant ratio to the anharmonic ratio of the stigmata of thosefourfixed s. points ; and this constant ratio is one of equality when the s. conic is a s. circle . In order to establish the latter part of this proposition , it is shown that in a s. circle , the s. tangent of the s. angle formed by any two s. rays drawn from a variable s. point to any two fixed s. points in the s. circle is constant ( which is a generalization of Euc . iii . 21 ) , whence is deduced the condition that four s. points should lie upon a s. circle . The classification of s. centrics is founded ( 102 ) on the first of the equations ( b ) . After showing how the two stigmata can be generally found from the index , the name of the s. centric is made to depend on the name of the locus of the stigma when the index describes the principal diameter in whole or in part . This locus is called the characteristic curve . According as o'e + o'g2 is a negative scalar , -1 , a positive scalar , + 1 , or any clinant , the s. centric is a s. ellipse , circle , hyperbola , equiradial ( equilateral hyperbola ) , or hyperellipse ( for which the characteristic is a confocal ellipse and hyperbola ) . The mode of finding the two indices corresponding to each stigma is then given ( 103 ) , and the circumstances under which a s. line and a s. centric may have common points investigated ( 104 ) . The mode of determining s. points of intersection , when there is no intersection in Cartesian geometry ( " imaginary " intersections ) is illustrated , and shown to lead to the same results as the homographic method . The radical axis ( 105 ) is shown to be the Cartesian portion of a s. line which is the common s. chord of a series of s. circles , so situated that the extremities of their principal diameters are the indices and stigmata of a s. involution , of which the " real " and " imaginary " circles of Chasles are two particular cases . The properties of asymptotes , and the nature of those in a s. ellipse , are then considered ( 106 ) , and their geometrical properties examined . Conjugate Diametrics and their relations to the asymptotes are next investigated , ( 107 ) . In especial it is shown that if ( u'e ' ) , ( v'g ' ) are two of the s. points in which two conjugate diametrics intersect a s. centric , and if the s. line drawn from ( u'e ' ) s. perpendicular to the diametric connecting ( o'o')and ( v'g ' ) meet the latter in a s. point whose stigma is D , we shall have ou ' . u'e ' +o'v'.'=0 , ... ... ... . . ( c ) o'u2 +o ' / 2 'e2 , u'e2+ v ' =og , ... ... ( d ) whence o'e'2+o'g'=o'e+o g2 ... ... . . ( e ) and de ' . ( o'v-v'g ' ) f+o'e o'g ... ... . . ) 200 [ June 14 , From these relations , which are much more general than any hitherto enunciated , the ordinary relations in Cartesian geometry respecting the lengths of conjugate diameters and the areas they contain are readily deduced . By referring s. centrics to conjugate diametrics as new coordinate axes ( 108 ) , a simple general method for constructing the intersections of a s. line with a s. centric , and for drawing two s. tangents ( 109 ) from any s. point ( except the s. centre ) is obtained . This is illustrated by actual geometrical constructions corresponding to " imaginary " cases in Cartesian geometry . It is also shown how the chord of contact or polar may have a Cartesian portion when both the s. points of contact are non-Cartesian and hence " imaginary . " It is now possible ( 110 ) to demonstrate the fundamental anharmonic properties of tangents and asymptotes to a s. centric . If through four s. points in a s. centric , four tangents be drawn , intersecting any fifth tangent , and also four s. chords meeting in any fifth s. point in the s. centric , the anharmonic ratio of the four stigmata of the s. points of intersection of the four tangents with the fifth will be equal to the anharmonic ratio of the four s. chords ( which generalizes S. C. 2 , 5 , the demonstration being here direct and therefore widely differing from Chasles 's ) , whence , if twofixed tangents are cut by a moveable tangent the stigmata of its s. points of intersection with them will be the indices and stigmata of s. points in a s. homography . It is now possible to generalize the whole of Chasles 's S. C. , and make the theories applicable , mutatis mutandis , to s. conics . The s. foci of a s. centric ( 111 ) are defined as the s. points of intersection of any two tangents which are parallel to the asymptotes of a s. circle . Hence it is shown that there are four s. foci to a s. centric ; so that if o's2=o'e2-+o'g'=o'z2 , the two principal s. foci are ( ss ) ( zz ) , and the two transverse s. foci are ( o 's ) , ( o'z ) . When the s. centric is Cartesian , the two principal s. foci are those usually recognized , and the only two recognized by Chasles , S. C. 275 , 294 . The other two transverse s. foci have , however , been recognized as " imaginary " foci by Plucker ( System der a. Geometric , p. 106 , 1 . 6 ) , and by Salmon ( Conics , 4th ed. p. 242 ) . Besides the usual properties of the focal stigmata in Cartesian curves , the following entirely new correlative properties of the principal and transverse s. foci are demonstrated . Let there be two conjugate diametrics , and through any s. point in one draw a s. line parallel to the other , and let the stigmata of the s. points of intersection of the conjugate diametrics and the chord , with the s. centric , be respectively E ' , F ' ; G ' , H ' ; Yx , Y2 . From E , F ' draw straight lines PARALLEL to the bisectors of the angles Y1SY2 , YZY2 respectively , forming two sides of a triangle of which E'F ' is the base . Then the lengths of these sides will be mean propor . tionals between the lengths of SY1 , SY , , and ZY1 , ZY , respectively . This is a generalization of the usual property that the sum or difference of the s focal distances is the axis major in the ellipse or hyperbola . Preserving the same notation , take X ' the middlepoint of Y1Y2 , set o'f X'X3=X4X ' =O'S , and make X3Y"=Y2X3 , and XY " ' =Y-X4 . From the extremities G ' , Hi ' of the diameter CONJUGATE to that used in the last proposition , draw straight lines PERPENDICULAR to the bisectors of the angles Y"SY2 , Y"'ZY2 respectively , forming the two sides of a triangle of which G'H ' is the base . Then the lengths of these sides will be mean propor . tionals between the lengths of SYi , SY2 and ZY"t , ZY2 respectively . This is the correlative property of the transverse s. foci , which has no Cartesian analogue . The deduction and expression of these properties is extremely simple , and they are illustrated by a geometrical construction . Finally , the s. tangent of the s. angle which the s. rays drawn from any s. point in a s. centric to the two principal or the two transverse s. foci make with the s. normal at the s. point are equal and opposite , which is a generalization , for both pairs of s. foci , of the property from which the ordinary foci derived their name . The following problems are then solved ( 112 ) . First . Given two conjugate radii O'E ' , O/ 'G to find the principal and transverse axes of the Cartesian centric . The focal stigmata S , Z are found from ( e ) thus : from E ' draw E'M~ , E'tM perpendicular to 0'Gt , and equal to it in length ; join O'M , OI'M , bisect the angle MOW'M by 0'S , OtZ , which are in length mean proportionals between O'M , O'M ' . Then there are three solutions , giving an ellipse or two hyperbolas , according as both or only one of the conjugate radii meet the characteristic curve of the Cartesian centric . Second . Given any three s. points representing the s. centre , and the s. points of intersection of two conjugate diametrics with the s. centric , to find its principal and transverse axes . Third . Given three s. points , to find the axis of a s. circle passing through them . Fourth . Given any five s. points , to determine whether they lie on a s. centric ; and if so , to find its principal and transverse s. axes . Equation ( e ) is then applied ( 113 ) to obtain a more general conception of confocal s. centrics , and Carnot 's theory of transversals ( as generalized in the Introductory Memoir ) is applied to finding a new expression for the s. radius of curvature , applicable for any s. point of contact . The ordinary expression gives length and not direction , and applies only to Cartesian points . Similar investigations are very briefly given for s. acentrics ( 115-118 ) . In these memoirs on Plane Stigmatics , the writer has endeavoured to confine himself strictly to such a development of his theory as would suffice to establish , with geometrical severity , the following results , which he believes to be entirely new , and of great scientific importance to mathematics . First . The problem of the geometrical signiflcation of imaginaries in plane geometry is completely solved ; so that the terms " r eal " and " imaginary " are no longer required , and an unbroken agreement exists between plane geometry and ordinary commutative algebra . [ Julne 14 , 20 Imaginaries arise whenever an algebra is used which is more general than the geometry to which it is referred . Ordinary commutative algebra is an algebra of clinants , which corresponds to a geometry where not only the relative lengths , but the relative angular positions of straight lines are regarded . Now the geometry hitherto associated with it has been scalar , that is , has considered relative lengths , but only identity or opposition of direction . Thus in Cartesian geometry the abscissre and ordinates were necessarily supposed to be parallel to given lines ; and in homographic geometry , where the ordinates were not taken into account , their extremities were supposed to lie on one or two given lines . But the algebra employed in either case took no notice of these restrictions , and hence led to results which could not be interpreted-that is , " imaginaries . " The solution of the problem of imaginaries has , therefore , consisted in that stigmatic conception which removes these restrictions , freely introduces relative angular position , and makes the geometry coextensive with the algebra . In the course of these memoirs every fundamental case in which imaginaries occur has been separately examined and shown to be fully explained by this conception . Second . The coordinate geometry of Descartes , and the homographic geometry of Chasles , are only particular cases of the writer 's stigmatic geometry , identical in nature , and expressible by identical equations ; for both Cartesian and homographic geometry consist in the relation of index to stigma with various restrictions , which may or may not be regarded in stigmatic geometry . Third . The general theories of plane curves , as treated by ordinary coordinate geometry , by the systems of coordination introduced by Plucker , or the modes of investigation more recently developed by Chasles , and all the theories derivable from these , hold , IN THEIR INTEGRITY , for stigmatic curves ALONE . For in all these theories clinant algebra is associated with scalar geometry , for which the stigmatic conception enables us to substitute that clinant geometry which perfectly agrees with the algebra employed ; and the fundamental propositions of these theories have been extended accordingly in the course of these memoirs . The instrument by which the writer has been enabled to bring these investigations to a successful issue , has proved so serviceable and manageable , embracing old and new properties in a single equation , often rendering a general investigation more easy to conduct than the former special researches , and keeping the geometrical operations indicated clearly before the mind , that he would add as a subsidiary result of his theory : Fourth . A calculus and a notation have been invented and developed , which enable magnitude and direction upon a plane to be expressed by a single symbol , obeying the laws of ordinary algebra , closely resembling in appearance ( not in theory ) the notation employed by Chasles to represent magnitude and direction upon a straight line , and as easy of manipulation , 1866 . ] 203
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Fundamental Views regarding Mechanics. [Abstract]
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Proceedings of the Royal Society of London
Julius Pl\#xFC;cker
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6.0.4
null
null
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1,850
1,800
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http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112615
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http://www.jstor.org/stable/112615
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Formulae
52.699319
Fluid Dynamics
44.510935
Mathematics
[ 62.030582427978516, -27.886064529418945 ]
III . " Fundamental Views regarding Mechanics . " By Professor JULIUS PLU/ CKER , of Bonn , For . Mem. R.S. Received May 29 , 1866 . ( Abstract . ) Being encouraged by the friendly interest expressed by English geometricians , I have resumed my former researches , which had been entirely abandoned by me since 1846 . While the details had escaped from my memory , two leading questions have remained dormant in my mind . The first question was to introduce right lines as elements of space , instead of points and planes , hitherto employed ; the second question , to connect , in mechanics , both translatory and rotatory movements by a principle in geometry analogous to that of reciprocity . I proposed a solution of the first question in the geometrical paper presented to the Royal Society . I met a solution of the second question , which in vain I sought for in Poinsot 's ingenious theory of coupled forces , by pursuing the geometrical way . The indications regarding complexes of forces , given at the end of the " Additional Notes , " involves it . I now take the liberty of presenting a new paper , intended to give to these indications the developments they demand , reserving for another communication a succinct abstract of the curious properties of complexes of right lines represented by equations of the second degree , and the simple analytical way of deriving them . 1 . We usually represent a force geometrically by a limited line , i. e. by means of two points ( x ' , y ' , z ' ) and ( x , y , z ) , one of which ( x ' , y ' , ' ) is the point acted upon by the force , while the right line passing through both points indicates its direction , and the distance between the points its intensity . We may regard the six quantities - ' , y-y ' , --z ' , yz'-y'S , zx'-z'x , xy'--xy ... . ( 1 ) as the six coordinates of theforce . The six coordinates of a force represent its three projections on the three axes of coordinates OX , OY , OZ , and its three moments with regard to the same axes . Accordingly we may , as far as we do not regard the point acted upon by the force , replace its coordinates by X , Y , Z , L , M , N ... ... ... ... . . ( 2 ) in admitting the equation of condition LX+MY+NZ=O , ... ... ... ... ... ... ( 3 ) which indicates that the axis of the resulting moment is perpendicular to the direction of the force . In making use of the primitive coordinates this condition is involved in the form given to them . When the last condition is not satisfied , the coordinates X , Y , Z , L , M , N represent no longer a mere force ; they are the coordinates of what I proposed to call a dyname . In the general case such a dyname results when any numbers of given forces act upon any given points . Here the six coordinates of the dyname are the sums of the six coordinates of the given forces ( x ' , y ' , ' , , y , ) . If between the six sums thus obtained , 2(X-x ' ) , 2(y-y ' ) , 2 ( - , ' ) , ( 4 ( yz'-y'z ) , ( zx'-z'x ) , ( xy'-x'y ) , ... ... an equation analogous to ( 3 ) takes place , there is a resulting force . In the case of equilibrium the six sums become equal to zero . 2 . In quite an analogous way as we have determined an ordinary force by means of two points in space , one of which is the point acted upon , we may represent a rotation , or the rotatory force producing it , by means of two planes , t'x + 'y + v ' = , tx+uy + vz=l , the coordinates of which are t ' , u ' , v ' and t , u , v , one of the two planes ( t ' , u ' , v ' ) being the plane acted upon . The right line along which both planes meet is the axis of rotation . The plane acted upon may in a double way turn round the axis of rotation in order to coincide with the second plane ( t , u , v ) ; but there is no ambiguity in admitting that during the rotation the rotating plane does not pass through the origin , and consequently its coordinates do not become infinite . Let us regard the six quantities t-t ' , U , uv-v ' , zv'-u'v , vt'-v't , tu'-t'u ... ... ( 5 ) as the six coordinates of the rotatory force . As far as we do not regard the plane acted upon , we may replace them by X , ? ) 3 , 3 , 9 ) , ( , ... ... ... ... . . ( 6 ) in admitting the equation of condition , +9J2)+ 3 *-*= 0 ... ... ... ... ... ... ... ( 7 ) ( For the geometrical signification of these new coordinates I refer to the original paper . ) When the last equation of condition is not satisfied , the coordinates X , 9 ) , ? 3 , 9J , 9t no longer represent a mere rotatory force ; they are the six independent coordinates of what I called a rotatory dyname . In the general case , such a rotatory dyname results when any number of given rotatory forces acts on any given planes . IIere the six coordinates of the resulting rotatory dyname are the six sums of the six coordinates of the given rotatory forces . E2(t-rt ) , ; ( u-u ' ) , ( v-- ' ) , ( 8 ) Z(UV'--u'v ) , M(vt'-vt ) , ( t-t'u ) ... ... . . If between these six coordinates the equation of condition subsists , there is a resulting rotatory force . In the case of equilibrium the six sums become equal to zero . Any movement whatever may be referred as well to ordinary as to rotatory forces ; consequently an ordinary dyname and( a rotatory dyname mean the same . 3 . From the notions developed we immediately obtain two general theorems constituting the base of statics . In a similar way as d'Alembert 's principle is derived from the " principe des vitesses virtuelles , " both theorems may be transformed into fundamental theorems of mechanics . In starting from the coordinates of ordinary forces , the equations of equilibrium are:s( , - ) =O , 2(y-y ' ) =0 , ( z- : z ' ) =0 , l ( O ) ( yz'-y'z)=0 , 2(zx'--'x)=0 , s( y''y_)=0 , " which , by replacing these forces by rotating ones , become ( t-t ' ) =0 , E ( u-u ' ) =0 , X(v-v ' ) =0 , . ( 10 ) z(uv'-u'v)=0 , :(vt'-vt ) =0 , E(tu'-t'u ) = . J We likewise may express the conditions of equilibrium by the following six equations( , --')= 0 , S(y-y ' ) =0 , ( z--z')=0 , }..l 2(t-t ' ) =0 , 2(U-u')=0 , 2(V-V')=o , " ( three of which are taken amongst ( 9 ) , three amongst ( 10)-and expand these equations in the analytical way , starting either from the consideration of ordinary or rotatory forces . The interpretation of these equations immediately gives the following two theorems . In the case of equilibriumI . The centre of gravity of the points acted upon by the forces coincides with the centre of gravity of the second points , by means of which the forces are determined ( No. 1 ) . II . The central plane of the planes acted upon by the rotatory forces coincides with the central plane of the second planes , by means of which the rotatory forces are determined ( No. 2 ) . If we introduce the notion of masses , both theorems hold good , only the definition of both kinds of forces and therefore their unity is changed . The points acted upon become centres of gravity corresponding to masses ; the planes acted upon , central planes corresponding to moments of inertia . If equilibrium does not exist , we get , in the general case , one resulting force , determined by the two centres of gravity , and one resulting rotatory force determined by the two central planes . We easily obtain the six differential equations of the imovement produced . I shall think it suitable further to develope the principles merely indicated in the paper presented . A Treatise on Mechanics , reconstructed on them , will assume quite a new aspect . 4 . In making use , within a plane , of pointor line-coordinates , we represent , by means of an equation between the two coordinates , a plane curve described by a point , or enveloped by a right line . In making use , in space , of pointor plane-coordinates , by means of an equation between the three coordinates , a surface is represented which may be regarded as a *The coordinates of the central plane are obtained in the same way by means of the coordinates of the given planes as the coordinates of the centre of gravity are obtained by means of the coordinates of the given p6ints . locus of points , or an envelope by planes . In my geometrical paper I introduced the right line , depending on four constants , as the element of space . An equation between these constants , if regarded as variables , represents a complex of lines . Each line of the complex maybe regardedeither as a ray described by a point , or as an axis enveloped by planes . In order to render the developments symmetrical , I adopted as coordinates of the right line the same expressions ( 1 ) and ( 4 ) ( connected by an equation of condition ) made use of in the determination of ordinary and rotatory forces . At the same time , general equations between the six coordinates were replaced by homogeneous ones . In doing so , A , B , C , D , E , F denoting any six constants , A(x--x ' ) +(y-y')+ C(z-z')+D(yz'y'z ) ... ... ( 2 ) I ... ... . . } ... ( 12 ) +E(yx'-y'x ) +F(xy'+x'y ' ) -=O , J* A(uv'-u'v ) +B(vt'--v't ) +C(tu't ' u ) +D(t-t')+E(u-u')+F(v-v ' ) O J. * ( 1**** represent the same linear complex of lines , which may be regarded as a complex of rays as well as a complex of axes . When general equations between the same six coordinates are admitted , the complex of rays becomes a complex of ordinary forces , the complex of axes a complex of rotations or rotatoryforces , both ordinary and rotatory forces depending upon five constants . Here we meet a reciprocity between both kind of forces corresponding to the reciprocity between point and plane . Finally , in omitting the equation of condition hitherto made use of , we pass from forces to dynames , depending upon the six independent constants X , Y , Z , L , N , N , ... ... ... . . ( 14 ) or , , 3 , ... ... ... ... ... ( 15 ) A complex of dynames is represented by an equation between six variables . I-ere again , as in the case of right lines , the same complex may be represented in a double way by means of the two sets of coordinates . In order to complete these general considerations , we add the following . A dyname may be resolved into two variable forces , either ordinary or rotatory . These variable forces constitute a linear complex , either of ordinary or extraordinary forces . A homogeneous equation between the six independent coordinates ( 14 ) or ( 15 ) represents a complex of two coupled variable right lines . 5 . I will conclude by giving some details regarding complexes of the first degree . A linear complex of ordinary forces is represented by the linear equation ~== 1 , which may be expanded thus : ( A + Fy'-Ez ' ) x+ ( BFx'--Dz')y ( + ( C +Ex'-.Dy')z In putting x ' , y ' , z ' as constants , those forces of the complex are obtained which pass through the given point ( x ' , y ' , z ' ) . In this supposition the equation of the complex becomes the equation of a plane . This plane is the locus of the second points , by means of which the forces of the complex are determined . Hence in a linear complex there are acting on each point of space forces in all directions , the intensity of each force being the segment on its direction between the point acted upon and its corresponding plane ( 16 ) . Hence we derive the following theorem : In a complex of rotatory forces any given plane of space is acted upon by an infinite number of forces , each line within the plane being an axis of rotation . The rotations round all axes are determined by second planes passing through a fixed point , the position of which depends upon the given point . I showed in the geometrical paper the way of discussing linear complexes of right lines . The properties of linear complexes of forces , either ordinary or rotatory , may be developed in a similar way . 6 . Right lines belonging simultaneously to two complexes constitute a single congruency , and accordingly intersect two fixed lines ; if belonging to three complexes , they constitute a double congruency , i. e. one generation of a hyperbolic or parabolic hyperboloid . Forces , either ordinary or rotatory , belonging simultaneously to two , three , four complexes , constitute a single , double , or threefold congruency of forces . In admitting these denominations , the following results arc immediately obtained . In a linear congruency of ordinary or rotatory forces , the directions of all ordinary , or the axes of all rotatory forces , constitute a linear complex of lines . All ordinary forces acting on any given point of space are confined within the same plane ; the intensity of each force is equal to the distance between the point acted upon and the point where its direction meets a fixed line within the mentioned plane . The axes of all rotatory forces , acting upon any given plane of space , meet in a fixed point within that plane . There is a fixed line passing through the fixed point , round which the second planes of all forces turn when their axes turn round the fixed point in the given plane acted upon . In a double congruency of ordinary forces there is one force of given direction and intensity acting upon any point of space , as there is in a double congruency of rotatory forces one force acting upon any given plane . In a threefold congruency of ordinary forces the directions , in a threefold congruency of rotatory forces the axes of all forces constitute one of the two generations of a hyperboloid . These few indications may be sufficient here ; but before concluding I must , in referring to the original paper , make a last remark . Forces acting along a given right line may either be regarded as the same , whatever may be the point of the line acted upon , or they may be regarded as varying in intensity according to the position of the point . There is an analogous distinction to be made with regard to rotatory forces . Accordingly two different kinds of complexes must be distinguished . 208
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Contributions to Terrestrial Magnetism.--No.X. [Abstract]
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Proceedings of the Royal Society of London
Edward Sabine
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
1
15
422
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112616
null
http://www.jstor.org/stable/112616
null
null
Biography
45.329302
Meteorology
43.421264
Biography
[ 55.997230529785156, 5.646182060241699 ]
IV . " Contributions to Terrestrial Magnetism.-No . X. " By Lieut. General EDWARD SABINE , R.A. , President of the Royal Society . Received June 7 , 1866 . ( Abstract . ) In this number of the Contributions to Terrestrial Magnetism the author resumes the discussion of the results obtained in the Magnetic Survey of the Southern Ocean by the Expedition under Sir James Clark Ross , R.N. , and Captain Francis Rawdon Crozier , R.N. , between the years 1839 and 1843 . The proceedings during the two first years of this Survey have been the subjects of two preceding numbers of the Contributions , viz. of Nos. V. and VI . , in the Philosophical Transactions for 1843 and 1844 . The present number contains a similarly detailed exposition of the operations of the third year of the Survey , comprehending the Southern Atlantic between Cape Horn and the Cape of Good Hope , and completing the circumnavigation of the southern hemisphere , from the departure of the expedition from the Cape of Good IIope in March 1840 , to the return to the same station in April 1843 . In a subsequent memoir , which will be presented to the Royal Society early in the ensuing Session , the author proposes to connect and thoroughly coordinate the three portions of the Survey , and to supply from them the numerical data at equidistant points on each of the three parallels of 50 ? , 60 ? , and 70 ? of south latitude , of the three magnetic elements , which will be required for a revision of the 'Allgemeine Theory des Erdmagnetismus ' of M. Gauss the 40th parallel having been the most southern available at the epoch of the publication of the original work . The instruments employed in this Survey , as well as the methods of employing them , and of eliminating the disturbing influence of the iron in the equipment of the vessels , having been in a great measure of a novel character , a discussion of considerable length bearing on all such points is prefixed to a full detail of the observations themselves , arranged in Tables , showing in every instance both the immediate results of the observations , and the corrections which have been applied in conformity with the principles contained in the preliminary discussion . Tabular abstracts are also furnished , exhibiting the results of the determinations of each day , with the appropriate geographical positions .
112617
3701662
On the Relation of Rosaniline to Rosolic Acid
209
213
1,866
15
Proceedings of the Royal Society of London
H. Caro|J. Alfred Wanklyn
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0047
null
proceedings
1,860
1,850
1,800
5
95
2,195
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112617
10.1098/rspl.1866.0047
http://www.jstor.org/stable/112617
null
null
Chemistry 2
74.946182
Biography
11.411209
Chemistry
[ 55.963436126708984, 5.662424564361572 ]
IV . " Contributions to Terrestrial Magnetism.-No . X. " By Lieut. General EDWARD SABINE , R.A. , President of the Royal Society . Received June 7 , 1866 . ( Abstract . ) In this number of the Contributions to Terrestrial Magnetism the author resumes the discussion of the results obtained in the Magnetic Survey of the Southern Ocean by the Expedition under Sir James Clark Ross , R.N. , and Captain Francis Rawdon Crozier , R.N. , between the years 1839 and 1843 . The proceedings during the two first years of this Survey have been the subjects of two preceding numbers of the Contributions , viz. of Nos. V. and VI . , in the Philosophical Transactions for 1843 and 1844 . The present number contains a similarly detailed exposition of the operations of the third year of the Survey , comprehending the Southern Atlantic between Cape Horn and the Cape of Good Hope , and completing the circumnavigation of the southern hemisphere , from the departure of the expedition from the Cape of Good IIope in March 1840 , to the return to the same station in April 1843 . In a subsequent memoir , which will be presented to the Royal Society early in the ensuing Session , the author proposes to connect and thoroughly coordinate the three portions of the Survey , and to supply from them the numerical data at equidistant points on each of the three parallels of 50 ? , 60 ? , and 70 ? of south latitude , of the three magnetic elements , which will be required for a revision of the 'Allgemeine Theory des Erdmagnetismus ' of M. Gauss the 40th parallel having been the most southern available at the epoch of the publication of the original work . The instruments employed in this Survey , as well as the methods of employing them , and of eliminating the disturbing influence of the iron in the equipment of the vessels , having been in a great measure of a novel character , a discussion of considerable length bearing on all such points is prefixed to a full detail of the observations themselves , arranged in Tables , showing in every instance both the immediate results of the observations , and the corrections which have been applied in conformity with the principles contained in the preliminary discussion . Tabular abstracts are also furnished , exhibiting the results of the determinations of each day , with the appropriate geographical positions . June 21 , 1866 . Lieut.-General SABINE , President , in the Chair . Dr. Hugo Muller , Mr. Perkin , the Rev. Canon Selwyn , and the Rev. R. Townsend , were admitted into the Society . I. " On the Relation of Rosaniline to Rosolic Acid . " By II . CARO , and J. ALFREJD WANKLYN , Professor of Chemistry at the London Institution . Communicated by Dr. FIANKLAND . Received June 5 , 1866 . At the Meeting of the British Association held in Bath in the year 18G(1 , it was pointed out by one of us that rosaniline and rosolic acid might be represented as ethylene which had undergone substitution : Type . Rosaniline . llosolic Acid . T II OII NC0II IOCJI , 2{ I ; C)N C011 , 1 ' HJ0 CG III II I OIL Rosaniline and rosolic acid became members of the same family , the former being an ethylene containing N{ CiI5 in place of hydrogen , the latter also an ethylene , but containing O C , : II , and O II in place of hydrogen . Some of the reasons for assigning these formulm were given in the communication made to the Bath Meeting . The relationship between rosaniline and rosolic acid is very well brought out by the facts which will presently be brought forward . Griess has shown that aniline and nitrous acid yield water and diazobenzol : Aniline . Diazobenzol . C , II NI+H NO = C , II , N , , + 21 , 0 . Diazobenzol is a most remarkable compound , forming salts which are very explosive , and which undergo certain very interesting transformations under the influence of reagents . It is moreover the representative of a numerous class of compounds derived similarly by the action of nitrous acid on different bases , and for the most part resembling itself in the explosive character of the salts . One of the most remarkable reactions presented by diazobcnzol is that with water , wherein the whole of the nitrogen of the diazobenzol is evolved , and its place supplied by an atom of water : Nitrate of diazobenzol . Carbolic acid . C , I11N INO3 + II , O = CHO1 , + IINO +N , . This elegant form of reaction appears to be characteristic of the class to which diazobenzol belongs ; and Griess has resorted to a measurement of the quantity of nitrogen set free during the reaction , as a means of arriving at the composition of the azo-compounds . IIofmann showed , some years ago , that rosaniline , after treatment with nitrous acid , is capable of forming a platinum cormpound endowed with explosive properties , but appears not to have followed the investigation further . Paraf has recently sllown that rosaniline salts are converted by nitrous acid into a dye , which he considered to be rosolic acid . We have also investigated the action of nitrous acid on rosaniline , and arrive at the following results : When an acid solution of a salt of rosaniline is mixed with nitrous acid , it forms an azo-compound , which corresponds very closely in character to diazobenzol . Like diazobenzol this compound forms explosive salts ; like diazobenzol it decomposes with evolution of nitrogen gas when it is boiled with acids . In adding the nitrous acid to the solution of rosaniline to form the compound , it is easy to observe the exact point at which the solution ceases to contain unaltered rosaniline . It thus becomes easy to determine the amount of nitrous acid consumed in the conversion of a given weight of rosaniline into the azo-compound . We have done this by the employment of a method which gives excellent results when applied to aniline and toluidine , and the details of which will shortly be published by one of us . We obtain as the result of our experiments , that one molecule of rosaniline consumes three equivalents of nitrous acid ; and the equation representing the reaction will be Rosaniline . Azo-compound . C 11 N3+31-1 O , =N + 61,0.N C20 19 1N+3NN02 C20 oH0 N+ 6H1-12 . On boiling this azo-compound with hydrochloric acid , there is evolution of nitrogen gas . The volume of nitrogen was measured . The result was that one molecule of rosaniline , after conversion into the azo-compound , yields six equivalents of nitrogen . Azo-compound . C,20 -I , N+3 H,12 C0C 0 , ,03 + NG , These changes in composition are accompanied by striking physical effects . The deep-red solution of the salt of rosaniline becomes brown on the addition of excess of hydrochloric acid , then yellow as the nitrous acid is added ; then there is much froth , and as the solution is boiled it gradually becomes red yellow , and a large quantity of a deep-coloured solid with cantharides-like lustre separates out . Seeing that this solid is produced by treating rosaniline with three equivalents of nitrous acid , and that six equivalents of nitrogen are evolved , it must be a non-nitrogenous substance . A careful comparison of its properties and reactions with those of the rosolic acid described by Kolbe and Schmitt , and now made largely as an article of commerce , leads to the conclusion that it is identical with rosolic acid . The following characters are common to it and to the rosolic acid of Kolbe and Schmitt . 1 . A yellowish-red solid with cantharides-like lustre , only sparingly soluble in water , soluble in ether and alcohol . 2 . Easily soluble in ammonia , and in alkalies generally , forming red solutions of very great colouring-power . Addition of acids to these solutions decolorizes them , precipitating the colouring-matter in the form of a yellowish precipitate , which varies much in tint . 3 . When boiled with aniline and a little benzoic acid , it forms a blue dye , there being no evolution of ammonia . The blue dye is very soluble in alcohol , not soluble in water ; it is the salt of a red-coloured base . It dissolves in strong sulphuric acid , giving a red solution . 4 . Submitted to destructive distillation , it gives abundance of carbolic acid , leaving a carbonaceous residue . 5 . The deep-red solutions in alkalies are easily reduced on boiling them with zinc powder ; so treated they lose their colour ; but restoration of the colour takes place on adding fcrricyanide of potassium . There is only one particular in which any difference could be detected between the product obtained from rosaniline and that obtained from carbolic acid by Kolbe and Schmitt 's process . The rosolic acid of Kolbe and Schmitt forms salts the solutions of which are darkened by ferricyanide of potassium . The product obtained from rosaniline does not darken , or darkens only very slightly , on the addition of ferricyanide . An explanation of this difference is afforded by the following experimental facts . The product from rosaniline after reduction with zinc becomes capable of being darkened by ferricyanide ; and if leucaniline , instead of rosaniline , be taken , there is obtained a cantharideslike product , which gives red solutions with alkalies , but is darkened by ferricyanide . Furthermore , if a solution of Kolbe and Schmitt 's rosolic acid be darkened with ferricyanide of potassium , and then precipitated by the addition of an acid , there results a colour-acid , which dissolves in alkalies , giving solutions of the exact tint of the rosaniline-product , and , like it , incapable of being deepened by ferricyanide . The interpretation of all this is , that the rosolic acid obtained from carbolic acid by the action of sulphuric and oxalic acid ( Kolbe and Schmitt ) contains more or less leuco-rosolic acid , produced probably by the reducing action of some sulphurous acid . The rosolic acid got from leucaniline also contains more or less leuco-rosolic acid . The rosolic acid obtained from rosaniline is free , or almost free , from leuco-rosolic acid . Be this , however , as it may , there can be no doubt that rosaniline and carbolic acid give essentially the same product when the former is treated with nitrous acid in the manner we have described , and the latter with sulphuric and oxalic acids as in Kolbe and Schmitt 's process . Adopting the " Ethylene type , " we have the following expressions for the reactions of rosaniline : Rosaniline . Azo-rosaniline . N CG II II II N ? 2 N 2C6 113 2 H.O CI NC6 EI , II N O , _ NC H2 NCJLHII +IINO1 , 2N 6C 3 2H,0 N C , IH5 1H +HN 0 , N , C , 11 , 2 H , 0 Rosolic Acid . C N. C( , + 110 OC-I +2Ne H{ C1t1 0 f , 11 2U32 1-12 6 On comparing the formula of rosolic acid given thus by Griess 's process applied to rosaniline , we find that it differs from the formula deduced from Kolbe and Schmitt 's analysis , viz. OC6 I-I5 OCJI , I OC 11 O65 OH by one atom of oxygen . We are inclined to think that this difficulty must be got over by correcting the formula deduced from Kolbe and Schmitt 's research . If the numbers required by the formulae C20 II 0L and C2o II , , O0 be calculated , it will be found that both of them fall sufficiently near the analytical results actually obtained to allow of the deduction of either from the analyses . Taking the latter , viz. C2o IHI 04 , all will become intelligible : Rosolic Acid . Type . Co C0 i , 11 C00 CHH C20 H18 ? l =C1--2 CH5 II H HII I0 -I IThus rosolic acid appears as an ethyl-hydride , and its generation in the Griess process applied to rosaniline is obvious . To the formula 0C115 0 Co HI H which is derived from rosaniline by the straightforward action of nitrous acid and water , we have to add I2 O , and we get 0c I ? I 11 IIo which is , as was said , a possible expression of the analyses of the rosolic acid obtained from carbolic acid . 1866 . ] 213
112618
3701662
On the Chemical and Mineralogical Composition of the Dhurmsalla Meteoric Stone
214
218
1,866
15
Proceedings of the Royal Society of London
Samuel Haughton
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0048
null
proceedings
1,860
1,850
1,800
5
150
1,696
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112618
10.1098/rspl.1866.0048
http://www.jstor.org/stable/112618
null
null
Chemistry 2
80.862909
Geography
6.367696
Chemistry
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II . " On the Chemical and Mineralogical Composition of the Dhurmsalla Meteoric Stone . " By the Rev. SAMUEL HATGHTON , M.D. , F.R.S. , Fellow of Trinity College , Dublin . Received June 6 , 1866 . On the 14th July 1860 , at 2.15 P.M. , a remarkable meteoric stone fell at Dhurmsalla , in the Punjab ; a small specimen of which was forwarded to the Geological Museum of Trinity College , which I have analyzed with the results contained in the following paper . The direction of the motion of the meteorite was ascertained to be from N.N.W. to S.S.E. The cold of the fragments that fell was so intense as to benumb the hands of the coolies who picked them up but who were obliged , in consequence of their coldness , instantly to drop them . The specific gravity of the Trinity College specimen was found as follows : Weight in air ... ... ... ... ... ... ... . . 3335*4 grs. Weight in water ... ... ... ... ... ... ... . 2354 1 , Sp.gr ... ... ... ... ... . . = 3-399 . The stone is grey , close-grained , and splintery in fracture , and presents fewer specks of metallic iron and magnetic pyrites than usual , and was coated with the ordinary black pellicle on its outer side . From 100 grs. acted on with iodine , which dissolved the alloy of iron and nickel , there were obtained , of peroxide of iron 9'85 grs. , and of protoxide of nickel 1 96 gr. The portion insoluble in iodine was next acted on by dilute muriatic acid and evaporated to dryness at 212 ? , then moistened with muriatic acid and filtered , by which process it was divided into a soluble and insoluble portion ; the portion left on the filter was boiled with carbonate of soda , so as to dissolve the free silica , which was found to be 18'95 grs. This was added to the portion originally soluble in muriatic acid , so as to give the following results:grs . Silica ... ... ... ... ... ... 18-95 Alumina ... ... ... 0 14 [ Present originally as Peroxide of iron ... ... . 14 ' 11 . protoxide and proto[ sulphuret of iron . Carbonate of lime ... ... ... ... none Pyrophosphate of magnesia ... . 51'31 Potash and soda chlorides ... 0'30 Platino-chloride of potassium. . 0-20 Oxide of manganese ( Mn3 04). . 0 66 On treating another 100 grs. of the meteorite for sulphur , by boiling in muriatic acid , and conducting th sulphllretted hydrogen into aln ammoniacal solution of sulphate of copper , so as to form a black precipitate of sulphlret of copper , there were foiund by the usual methods 14-8 grs. of sulphate of barytes . There were left , after treatment with ioldine , muriatic acid , and carbonate of so(la , 383 grs. of the 100 grs. originally act ( I upon . From the foregoing facts , we readily obtaini-from treatment with iodine and for sulphurgrs . grls . Peroxide of iron ... ... 9'85 ... . 6-88 iron Protoxide of nickel ... . 1-96 ... . 1 541 nickel Sulphate of barytes ... . 1480 ... . 561 protosulphuret of iron . IHence we find , as the primary analysis of the meteoriteI . Primary Analysis . 1 . Metallic iron ... ... ... ... ... ... ... ... ... ... . . 6-88 2 . Metallic nickel ... ... ... ... ... ... ... ... ... ... . . 1 5.1 3 . Magnetic pyrites ... ... ... ... ... ... ... ... ... ... 56 4 . Earthy mineral ( soluble ) ) ... ... ... ... ... ... ... ... 47(67 5 . Earthy mineral ( insoluble ) ... ... ... ... ... ... ... . 38-30 100'00 The results of the analysis of the soluble portion ( considering that 5( 61 of Fe S is equivalent to 510 of Fe2 O : ) give the following : II . Earthy Mineral ( soluble ) . grs. per cent. Oxygen . 1 . Silica ... ... ... ... 18-95 ... . 39-75 ... . 20637 2 . Alumina0 ... ... ... . 0 19 ... ... 0135 3 . Protoxide of iron ... ... -10 ... . 199 ... . 3768 4 . Protoxide of manganese 0'66 ... . 1'38 ... 0-308 5 . Lime ... ... ... ... . . none ... ... . 6 . Magnesia ... ... ... ... 318 4. . 38 ... 15-374 7 . Potash ... ... ... ... 004 ... . 10 0 001 8 . Soda ... ... ... ... 0 3 ... . 028 ... . 0-071 9 . Loss ... ... ... ... 131 ... . 2-74 ... . 47-67 100()00 40309 Adding together the oxygen of the protoxides , we findRO ... ... ... ... . 19537 Si O ... ... ... ... ... . 0637120i2 ~~Sit)2 . 20637 } 20772 Al,3 . ) . 0'135 J From the preceding result , it is evident that the soluble mineral in this meteorite is chrysolith , or the silicate of magnesia and iron represented by the formula 3 RO , Si O ; in which magnesia preponderates greatly over the iron . The 38'3 grs. of mineral , insoluble in muriatic acid and in carbonate of soda , were now divided into two equal portions , of which one was fluxed with carbonates of soda and potash , and the other with lime and chloride of ammonium-with the following results:grs . Silica ... ... ... ... ... ... ... ... ... ... ... 10-85 Alumina ... ... ... ... ... ... 0-23 Peroxide of iron ... ... ... ... ... ... ... ... . . 2'51 Oxide of manganese ( Mn3 0 ) ... ... ... ... ... . 030 Oxide of chrome ( Cr2 03 ) ... ... ... ... ... ... . . 1'42 Carbonate of lime ... ... ... ... ... ... ... ... . . none Pyrophosphate of magnesia ... ... ... 11 50 Potash and soda chlorides ... ... ... ... ... . . 0'30 Platino-chloride of potassium ... ... ... ... . . 050 Assuming the chrome to be present as chrome-iron , Fe O , Cr2 03 , we find grs. Original weight ... ... ... ... ... ... ... ... ... 19 15 Chrome-iron ... ... ... ... ... ... ... ... ... 2*08 Earthy insoluble ... ... ... ... ... ... ... 17-07 If we now omit the chrome-iron and make the necessary reductions in the foregoing results , we obtainIII . Earthy Mineral ( insoluble . ) grs. per cent. Oxygen . Silica ... ... ... 1085 ... . 63-56 ... . 33-000 Alumina ... ... ... ... 0-23 ... . 1'34 ... . 0'525 Protoxide of iron ... . 1-60 ... . 9-37 ... . 2078 Protoxide of manganese 0-30 ... . 1-75 ... . 0-392 Lime ... ... ... ... . . none ... . Magnesia ... ... . . 4-13 ... . 24-19 ... . 9-666 Soda ... ... ... ... . 008 ... . 047 ... 0119 Potash ... ... ... ... 009 ... . 0-52 ... . 0-087 [ Gain ] ... ... ... ... [ 0-21 ] ... . [ 1-20 ] ... . 17-07 100-00 45-867 The oxygen of the protoxides of the preceding analysis amounts to 12*342 per cent. , but it would be fallacious to form any opinion as to the composition of the whole , so long as we are not acquainted with the constituent minerals that compose it . Collecting together into one view the preceding results , we findIV . Mineralogical Composition of the Dhurmsalla Meteorite . 1 . Nickel-iron ... ... ... ... ... . 82 Nic 68854 Nickel 1-54 2 . Protosulphuret of iron ... ... 5-61 3 . Chrome-iron * ... ... ... ... . . 416 4 . Chrysolith ( peridot or olivine ) 47'67 5 . Minerals insoluble in muriatic acid 34 14 100-00 I shall here add , for the purpose of comparison , the results of my analysis of the meteoric stone that fell at Dundrum , co . Tipperary , at 7 P.M. of the 12th August , 1865 . Dundrum Meteorite . Sp. gr ... ... ... ... 3-066 to 3-570 . I. Mineralogical Composition . 1 . Nickel-iron ... ... ... ... ... .20-60 { In.ickel 195703 2 . Sulphur-iron ... ... ... ... ... . 4-05 3 . Chrome-iron ... ... ... ... ... . 1'50 4 . Chrysolith ... ... ... ... ... . 33-08 5 . Earthy minerals insoluble in muriatic acid ... ... ... ... ... . 40-77 100-00 II . Chemical Composition of the Chrysolith . Silica ... ... ... ... ... . 38-74 ... ... . . 38-86 Alumina ... ... ... ... ... 0-Protoxide of iron ... ... 16-55 ... ... . . 19i74 Protoxide of manganese. . 015 ... ... . . -Lime ... ... ... ... ... 084 ... ... . 072 Magnesia ... ... ... ... 40'93 ... ... . . 36-85 Potash ... ... ... ... . . 0-51 ... ... . . 0-47 Soda ... ... ... ... ... 0-24 ... ... . . 0-22 Loss ... ... ... ... ... . 1 ' 59 ... ..1 ... 3-14 100-00 100-00.4 III . Chemical Composition of the Earthy insoluble Minerals . Silica ... ... ... ... ... ... . . 61'-33 Alumina ... ... ... ... ... ... 1 '72 Protoxide of iron ... ... ... . . 6'06 Protoxide of manganese ... ... 0'78 Limre ... ... ... . 3 ' ! ) ! ) Magnesia ... ... ... ... ... . . 22'02 Soda ... ... ... ... ... ... . . 1-38 l'otash ... ... ... ... ... ... . . 083 Loss ... ... ... ... ... ... ... . 1889 100'00
112619
3701662
On the Preparation of Ethylamine
218
220
1,866
15
Proceedings of the Royal Society of London
J. Alfred Wanklyn|Ernest T. Chapman
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0049
null
proceedings
1,860
1,850
1,800
3
56
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http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112619
10.1098/rspl.1866.0049
http://www.jstor.org/stable/112619
null
null
Chemistry 2
90.917982
Chemistry 1
3.576935
Chemistry
[ -43.54814147949219, -63.7170524597168 ]
" On the lreparation of Ethylamnine . " By J. ALFRED WANKLYN , and I NEIL'1ST ' T. CIIHAPMAN . Communicated by Dr. FRANKLAND . Received June 8 , 1866 . Iaving recently had occasion to prepare a considerable qulantity of ethylamnile , we have made the observation that this base may be obtained withi rmuch greater facility than is usually believed . We digested together equial volrunes of iodide of ethyl , strong alcohol , iand aqueous anmmonlia . The digestion was carried oii at a very moderate temperaturec , certainly not exceeding 80 ? , but the tubes were constantly agitated . In this manner the reaction is completed in about half an hour . The mixed iodides tiius obtained were evaporated to exipel excess of ammonlia , introduced into a retort ; enough potash was added to neutralize I , of the io(line present , and the mixture was distilled into dlilute hydroclloric acid( . The receiver was thei changed , the samen quantity of Iotash agaill added , and the products collected as before . Then six times as much potash was added , and the products collected . The remaini:lg two-tenths of the potash were added separately . Portions of each of these fractions were converted into p)latinum salts , andi the amount of platinum was determinei d by ignition . Eacl of the first four fir'.ctions corresponding to -t of the total bases obtained , gave more pIlatin:um than corresponds even to pure ethylalmine , and therefore contained ethylamine and am orno ia . Only the last fraction , corresponding to -l , of the enltie bases , gave a lower Iercentage of platinum than corresl)ol(ls to ethylaminle , and tlerefore colltained the dialnd tri-bases . Subjoined are the platilum determinations in this last fraction : I. 0-2133 grin . gave 0-0830 Platinum II . 0-35 ! 0 , , ) 0-1382 or , I. Platinum per clent . 38-91 1 . , , , , , 38'5 Pt Cl. N C , II ; IIl ( C1 contains 39-37 per ceiit . of Pt. l't Cl. N ( ( C , II . , ) , 11 . Cl contains 33542 , , Froml which it will be seen that even the last tenth of the bases did not contain much diand tri-bases . The former a gave , as aforesaid , rather more platinum than ethylamine salt yields , and therefore contained ammonia . In order to make out whether there was any diand tri-base along with the ethylamine il these former fractions , we took No. 3 ( corresponding to ' ; Y ) dm and made a platinum-fractionation as follows : No. 3 gave 40-62 and 40'13 per cent. of platinum . No. 3 , after some pure chloride of ammonium had crystallized out ( the crystals were analyzed and proved to be quite pure chloride of ammonium ) , was converted into a platilum-salt , and that platinum-salt fractionated so as to leave the portion richest in the high bases . This salt , which would be rich in the diand tri-bases if any had been present in No. 3 , gave this result:*7666 grm. gave '3090 grm. of platinum=Pt per cent. 400(3 . From which it is manifest that diand tri-bases were absent . From the foregoing we concluded that all the higher bases were concenltrated in the last fraction , but that ammonia passed over during the whole distillation . The objection might therefore be made that mixtures of ammonia and diand tri-ethylamines would give the same numbers . In or(ler to deprive this objection of its force we made the following experiments . Iodide of ethyl , alcohol , and ammonia were digested as before , and the mixed iodides so obtained distilled from excess of potash , the vapour thus obtained absorbed by dilute sulphuric acid , care being taken that the acid was not in excess . The fluid so obtained was rendered very slightly acid with the same acid , and then evaporated on the water-bath . The sernisolid residue was treated with strong alcohol , and allowed to stand one night . It was then filtered , the filtrate measured , and the amount of sulphuric acid determined in a measured portion . Enough K II O was then added to the alcoholic liquid to liberate -sof the bases present . The potash was added in solution in water . The liquid was then distilled , the distillate being received in dilute hydrochloric acid . A portion of this liquid was then evaporated to dryless and placed over sulphuric acid . Its percentage of chlorine was then determined : ? 3826 of salt gave '6696 Ag Cl ; . 4329 per cent. 1C . 'Theory -13')5 . From these numbers it is obvious that the subs:ance must have been pure ethylamine . It could have contained no ammonia , or at most only minute traces , and therefore the above objection is completely disposed of : A portion of this pure hydrochlorate of ethylamine was then treated with aqueous ammonia il insufficient quanltity to combine with the wliole of the hydrochloric acid Ipesenlt . We distilled this liquid inlto dilute hydr-ochloric acid , evaporated it to dryness , and determined the amount of chlorine present in the residue . The result was:*4528 of salt gave 1 3155 AgC1 ; . ' . 59'94 per cent. C1 . Chloride of ammonium would give 66'33 , , Chloride of ethylamine ... ... . . 43'55 , , From these numbers it appears that ammonia is capable of partially expelling ethylamine from its compounds , and thus we have an explanation of the apparent anomaly of the appearance of ammonia with the ethylamine in the above-described experiments . It appears therefore that pure ethylamine may be readily obtained in the following manner . Equal volumes of iodide of ethyl , strong alcohol and ammonia are to be digested together for about half an hour , at a temperature somewhat below that of boiling water , with continual shaking ; the product of this operation boiled to expel excess of ammonia , and then distilled from potash the distillate being received into dilute sulphuric acid , the ammonia separated by means of alcohol , and the alcoholic solution of the mixed sulphates treated with sufficient potash to liberate about 9of the bases present . On distilling this mixture , pure ethylamine , accompanied with alcohol and water , are the sole products found in the distillate .
112620
3701662
On the Expansion by Heat of Metals and Alloys. [Abstract]
220
222
1,866
15
Proceedings of the Royal Society of London
A. Matthiessen
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
3
98
1,416
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112620
null
http://www.jstor.org/stable/112620
null
108,962
Thermodynamics
40.223433
Chemistry 2
36.972024
Thermodynamics
[ -9.757425308227539, -77.69698333740234 ]
IV . " On the Expansion by Heat of Metals and Alloys . " By A. MATTHIESSEN , F.R.S. Received June 14 , 1866 . ( Abstract . ) In a paper " On the Expansion by Heat of Water and Mercury"* , a method of determining the expansion of bodies is described , by which good results can be obtained with comparatively small quantities of the substances to be experimented with . This method , that of weighing the body in water at different temperatures , has been employed for the present research . The results obtained are given in the following Tables : TABLE I.-Formulke for the Correction of the Cubical Expansion by Heat Cadmium ... ... Zinc ... ... ... Lead ... ... ... . Tin ... ... ... . Silver ... ... . . Copper ... ... . . Gold ... ... ... . Bismuth ... ... Palladium ... ... Antimony ... ... Platinum ... ... of the Metals . Vt-=Vo ( 1 + 10-4 x 08078t+ 10-6 x 0140t2)t . Vt-=V ( 1 + 10-4 x 0-8222t+ 10-6 x 00706t2 ) . V= V0 ( 1 + 10-4 x 08177t+ 10-6 x 0.0222t2 ) . Vt , = V ( 1 10-4 x 0.6100t + 10-6 x 0.0789t2 ) . V , =tVo ( 1 + 10-4 x 0-5426t+ 10-6 x 0.0405t2 ) . Vt=Vo ( 1+ 10-4 x 04463t 10-6 x 0-0555t2 ) . Vt= V ( 1 + 10-4 x 04075+10-6 x 0'0336t2 ) . Vt , =Vo ( 1 + 10-4 x 0-3502t + 10-6 x 0.0446t2 ) . Vt=Vo ( 1 +10-4 x 0.3032t+ 10-6 x 00280t2 ) . Vt=V , ( 1 + 10-4 x0 2770t + 10-6 x 0-0397t " ) . V , =Vo ( 1 + 10-1 x0 2554t+ 10-6 x 0'0104t2 ) . TABLE II.-Formulae for the Correction of the Linear Expansion by Heat of the Metals . Cadmium ... ... L , =Lo ( + 10- ' x 0-2693t+ 10-6 x 00466t2 ) . Zinc ... ... ... . Lt=Lo ( 1 + 10- ' x 0'2741t+ 10-G x 00234t2 ) . Lead ... ... ... . L , ==L ( 1+ 10-1 x 0'2726t+ 10x 0-0074t2 ) . Tin ... ... ... . L=Lo ( + 10-x 02033t + 10- . x 00263 ) . Silver ... ... . . Lt=I= ( l+10- ' x 0'18091t+10-0 x 00135tF ) . Copper ... ... . . L , =Lo ( 1 +1 0x 048 1t + 10x OO185a ) . Gold ... ... ... . LL ( 1 + 10- ' x 01358t + 10X 00112t2 ) . Bismuth ... ... L , = L , ( 1 +10- ' x 0-11 67t + 10-0 x 0-0149t2 ) . Palladium ... ... L= Lo ( 1 + 10- " x.01O lt+ 10-0 x 000932t ) . Antimony ... ... Lt-=L ( 1 + 10- ' x 00923t+ 10-G 001 32t2 ) . Platinum ... ... L , =Lo ( 1+10- ' x 00850t+10-0 x 0-003512 ) . TABLE III.-Formulae for the Correction of the Cubical Expansion by Hleat of the Alloys . Sn , Pb : Vt=Vo ( 1 + 10- ' x 06200t+ 10-I x 0-0988t2 ) . Pb , Sn : V=Vo ( 1 + 10- ' x0 8087t +1 0- ' x 003'32t2 ) . Cd Pb : V=V0 ( 1 + 10-4 x 0'9005t + 10x 0'0133t2 ) . Sn4 Zn V , =V , ( 1 + 10x 0'6377t+ 10x 00807 t12 ) . Sn , Zn V , =V , ( 1 + 10x 0-6236t+ 10-0 x 0-0822f2 ) . Bi , , Sn : V=Vo ( 1 + 10x 0-3793t 10-6 x 0-0271 2 ) . BiSn2 : Vt=Vo ( 1 +10- " x 0-4997tt+ 10-6 X 00101 t2 ) . Bi2 , Pb : Vt=Vo ( 1 + 10- ' x 0-3868t + 10-6 x 0-0218t2 ) . Bi Pb2:Vt=Vo ( 1 +10x 0-84(2t+ 10-6 x 001.59t2 ) . Cu+ Zn ( 71 p. c. Cu ) : V =V , ( + 10-4 x 051611+ 10- " x 00558t2 ) . Au Sn , V-=Vo ( 1 + 10-4 x 0-3944t+ 10x 0-0289t2 ) . Au , Sn7 V , =V0 ( 1 + 10x 041651t+ 10- ? x 0-0263t2 ) . Ag , Au V , =V0 ( 1 . + 10-4 x 05166t ) . Ag Au V , =Vo ( 1 + 1.0-4 x 0491.6 ) . Ag Au , V , = V , ( 1 + 10-4 x 03115 + 10x 0.11851 " ) . Ag + Pt ( 66-6 p. c. Ag ) Vt=V0 ( 1 + 10- " x 0-4246t + 10-6 x 00322t2 ) . A+ Cu ( 66-6 p. c. Au ) Vt=Vo ( 1 + 10x 0-401)51t+ 10- ; x 0(064212 ) . Ag+ Au ( 36 1 p. c. Ag ) V , =V , ( 1 + 10x 0'4884t+ 10- ' ; x 0-0552t2 ) . Ag Au ( 71-6 p. c. Ag ) Vt=V , ( 1 + 1.0x Ol443.t + 10-0 x 0.01301t ) . nlmber of the zerios . I have also preferred keeping the exponents constant , adding , instead of altering them , a zero after the decimal point when required . TABLE IV.-Formulhe for the Correction of the Linear Expansion by IIeat of the Allovs . Sn1 Pb I , t= L , ( 1 + 10-- ' x 0206 ; ( t+-10-G x 0-0329t2 ) . Pb , Sn I , t= Lo ( 1 +10- ' x 0269( ; t+ 10- ' x0 '0111 t2 ) . Cd Pb L , = o ( 1 + 10x 0-3002t+ 10- ' ; x 00044t2 ) . Sn , Zn Lt= , ( 1 +10--l X 0-2126t+0-6 x 002( ; 91t2 ) . Sn , Zn L , = Lo ( 1 . + 10X 0 2079 ? t+1 0x 0-02i74t2 ) . Bi , , Sn L= L , ( 1 10-'x 0 ' 126t10X x 00090t ' ) . Bi Sn12 L= L , ( 1 + 10-l x 0-1 ( ; ( ( )t+ 0-1 x 0.0034t2 ) . Bi , Pb Lt , = Lo ( 1 + 10- ' x 0'1293 + ' 0- ' x0 '007312 ) . Bi Pl , Lt , =L ( 1 + 10- ' x 02821 . ? ? 10- ' ; x.00-:3t2 ) Cu + Zn ( 71 p. c. Cu ) L , = Lo ( 1 + 10- ' x 01 720t+ 10- ' x 0(00()S(2 ) . Au Sn2 L= L , ( 1 + 10x 0-:1151t+ 10x 0(00962 ) . Ag An t= L , , ( 1l + I0 x 01()1(38/ ) . Ag Au . , Lt= L , ( 1 + 10- ' X ( 03St+ 10x 0 )0395 , t ) . Ag+ Pt ( G6*6 p.c. Ag ) Lt= L , ( 1 ? +10- ' x 0:141)+1.0x 00107 2 ) . An ? +Cu ( GG66 p. c. Au ) L , = L , ( 1 + 10x 0I1 'l St+ 10x )00214'2 ) . Ag+Cu ( 36li p.C. Ag ) L , = 1 ( 1 . +10- ' x 01 128t +10- ' ; x 0'12t ' ) . Ag+ Cu ( 71 6 p. c. Ag ) L= Lo ( 1+10x 0x1471t 10- ' X 0 ' 043t2 ) . From the above the following conclusion is drawn-namely , that just as it may be said that the specific gravity of an alloy is approximately equal to the mean specific gravities of the component metals , so also from the foregoing we may deduce that the volume which an alloy will occupy at any tenmperature between 0 ? and 100 ? is approximately equal to the mean of the volumes of the component metals at the same temperature , or , in other words , the cubical or linear coefficients of expansion by heat of a'n alloy between 0 ? and 100 ? are approximately equal to the mean of the cubical or linear coefficients of expansion by heat of the compoonent metals . V. " On the Colouring and Extiaction Matters of the Urinc.-Plart II . " By EDWARD SCIIUNCK , F.R.S. Received June 20 , 1866 . See abstract , anttei ' , p. 1 .
112621
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On the Absorption and Dialytic Separation of Gases by Colloid Septa. [Abstract]
223
224
1,866
15
Proceedings of the Royal Society of London
Thomas Graham
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
2
35
895
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112621
null
http://www.jstor.org/stable/112621
null
108,953
Thermodynamics
67.098666
Chemistry 1
25.492616
Thermodynamics
[ -20.4576416015625, -47.5330810546875 ]
VI . " On the Absorption and Dialytic Separation of Gases by Colloid Septa . " By T-OMAS GRAHAM , F.R.S. , Master of the Mint . Received June 20 , 1866 . ( Abstract . ) It appears that a thin film of caoutchouc , such as is furnished by varnished silk or the transparent little balloons of india-rubber , has no porosity , and is really impervious to air as gas . But the same film is capable of liquefying the individual gases of which air is composed , while oxygen and nitrogen , in the liquid form , are capable of penetrating the substance of the membrane ( as ether or naphtha do ) , and may again evaporate into a vacuum and appear as gases . This penetrating power of air becomes more interesting from the fact that the gases are unequally absorbed and condensed by rubber , oxygen 2 ? times more abundantly than nitrogen , and that they penetrate the rubber in the same proportion . IHence the rubberfilm may be used as a dialytic sieve for atmospheric air , and allows very constantly 41'6 per cent. of oxygen to pass through , instead of the 21 per cent. usually present in air . The septum keeps back , in fact , one-half of the nitrogen , and allows the other half to pass through with all the oxygen . This dialysed air rekindles wood burning without flame , and is , in fact , exactly intermediate between air and pure oxygen gas in relation to combustion . One side of the rubber-film must be freely exposed to the atmosphere , and the other side be under the influence of a vacuum at the same time . The vacuum may be established within a bag of varnished silk , or in a little balloon , the sides being prevented from collapsing , by interposing a thickness of felted carpeting between the sides of the varnished cloth , and by filling the balloon with sifted sawdust . For commanding a vacuum in such experiments , the air-exhauster of Dr. I-ermann Sprengel* is admirably adapted . It possesses the advantage that the gas drawn from the vacuum can also be delivered by the instrument into a gas-receiver placed over water or mercury . The " fall-tube " has merely to be bent at the lower end . The surprising penetration of platinum and iron tubes by hydrogen gas , discovered by MM . H. Sainte-Claire Deville and Troost , appears to be connected with a power resident in the same and certain other metals , to liquefy and absorb hydrogen , possibly in its character as a metallic vapour . Platinum , in the form of wire or plate , at a low red heat may take up and hold 3'8 volumes of hydrogen , measured cold ; but it is by palladium that the property in question appears to be possessed in the highest degree . Palladium foil from the hammered metal , condensed so much as 643 times its volume of hydrogen , at a temperature under 100 ? C. The same metal had not the slightest absorbent power for either oxygen or nitrogen . The capacity of fused palladium ( as also of fused platinum ) is considerably reduced ; but foil of fused palladium , for which I am indebted to Mr. G. Matthey , still absorbed 68 volumes of gas . A certain degree of porosity may be admitted to exist in these metals , and to the greatest extent in their hammered condition . It is believed that such metallic pores , and indeed all fine pores , are more accessible to liquids than to gases , and in particular to liquid hydrogen . Hence a peculiar dialytic action may reside in certain metallic septa , like a plate of platinum , enabling them to separate hydrogen from other gases . In the form of sponge , platinum absorbed 1*48 times its volume of hydrogen and palladium 90 volumes . The former of these metals , in the peculiar condition of platinum-black , is already known to take up several hundred volumes of the same gas . The assumed liquefaction of hydrogen in such circumstances appears to be the primary condition of its oxidation at a low temperature . A repellent property possessed by gaseous molecules appears to resist chemical combination , as well as to establish a limit to their power to enter the minuter pores of solid bodies . Carbonic oxide is taken up more largely than hydrogen by soft iron . Such an occlusion of carbonic oxide by iron , at a low red heat , appears to be the first and a necessary step in the process of acieration . The gas appears to abandon half its carbon to the iron , when the temperature is afterwards raised to a considerably higher degree . Silver has a similar relation to oxygen , of which metal the sponge , fritted but not fused , was found to hold in one case so much as 7'49 volumes of oxygen . A plate or wire of the fused metal retains the same property , but much reduced in intensity , as with plates of fused platinum and palladium in their relation to hydrogen .
112622
3701662
Notes on the Rearing of Toenia echinococcus in the Dog, from Hydatids, with Some Observations on the Anatomy of the Adult Worm
224
226
1,866
15
Proceedings of the Royal Society of London
Edward Nettleship
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0052
null
proceedings
1,860
1,850
1,800
4
88
1,445
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112622
10.1098/rspl.1866.0052
http://www.jstor.org/stable/112622
null
null
Biology 2
41.146936
Paleontology
19.81782
Biology
[ -80.280029296875, 27.425600051879883 ]
VII . " Notes on the Rearing of Tacnia echinococcus in the Dog , from Hydatids , with some Observations on the Anatomy of the Adult Worm . " By EDWARD NETTLESHIP , Mem. Royal Agric . Coll. Communicated by T. SPENCER COBBOLD , M.D. Received May 24 , 1866 . On March 28th , 1866 , I obtained from Clare Market the liver and lungs of a sheep containing numerous Echinococcus hydatids ; in some the outer cyst was partly calcified , but all the hydatids contained clear fluid , and great numbers of scolices attached to the endocyst . Within two hours of the death of the sheep to which the organs belonged , I gave two or three of the smaller hydatids to a young dog , about six months old ; first puncturing the hydatid and administering the collapsed cyst , and then making him drink the fluid of the cyst , in which some Echinococci were floating . The next day I gave him a second feeding of the remaining hydatids ; this second batch he threw up within half an hour of the feeding , but he afterwards swallowed the broken membranes again , and did not afterwards vomit . I was careful to administer the hydatids from both calcified and non-calcified cysts . The animal remained perfectly healthy , and became very much fatter ; he was fed for the most part on cooked kitchen refuse , but I cannot be positive that he never obtained any raw food . On May 15th ( the forty-seventh day after the first feeding ) I killed the animal , and examined the intestines . In the first ten inches of bowel below the pylorus there were no Tnenise ; at that distance a single Taenia echinococcus appeared , moving actively ; for the next two or three inches there were none , but at about fourteen inches below the pylorus several more appeared , and immediately after this they became so numerous as to present almost the appearance of distended lacteals ; this continued for about a foot in extent , and then they gradually became less numerous , and ceased at about three feet from the pyloric orifice . There were also four specimens of T. marginata , varying from two to three feet in length , and two of T. cucumerina . The part of the intestine cnttaining T. echinococcus was immediately put into dilute carbolic acid , and the worms not examined until two days subsequently ; after that interval they were still tolerably adherent to the mucous membrane , though a good many had fallen off . On detaching them with needles , or examining those which had fallen off , nearly all were found to be quite destitute of hooks ; but one ( from which the outline sketch , Plate VIII . fig. 1 , was taken ) had a tolerably complete double row ; in this specimen , however , the hooks and proboscis were inverted , while in most specimens the latter part was protruded . In fig. 2 is a single hook of T. echinococcus , probably from the posterior circlet , magnified more highly . Fig. 3 shows at a , a hook of the posterior circlet , and at b , one from the anterior circlet of an Echinococcus-scolex from an ox . There seems very little difference between corresponding hooks of the scolex and of the adult tapeworm , unless the latter be rather stouter and have larger processes . On -lth of a square inch , where the worms were thickest , I counted twenty-five of them ; by calculation there were about twenty-two square inches of intestine covered in this way , allowing for the more thinly scattered parts at each end of the infected part ; this gives a total of 8800 specimens of T. echinococcus in this dog 's bowel . I have examined carefully numerous specimens of these worms with the microscope , with especial reference to the arrangement of the sexual organs ; the great majority are sexually mature , and contain a greater or less number of eggs . It is not easy to make out accurately the arrangement and connexions of the ovary , yelk-forming glands , and uterus , as described by Leuckart* , but fig. 4 gives a tolerably correct representation , in the 3rd ( immature ) segment . At a is the vagina , continued as an indistinct tube to b , which I suppose to be the seminal vesicle ; immediately beyond this is a dark mass ( o ) containing spherical , highly refractive bodies ; this is the ovary . On either side and in front of this are the yelk-forming glands ( e ) , two somewhat indefinite lobular organs apparently communicating with the vagina in front of the seminal vesicle . At c and d are the globular testicles ; f is the rudimentary vas deferens . Running forwards from the vagina is another narrower tube g , which passes quite to the anterior end of the segment , where it becomes at first slightly dilated ( fig. 5 , u ' ) , and afterwards enlarged into the head of the uterus ; a large spherical sac full of ova is readily seen with the naked eye in many sexually mature segments ( fig. 4 , ut . ) . The greater part of the body of this tube also becomes enlarged into the uterus ( u , fig. 5 ) , but I think that the hinder part continues tubular , and probably constitutes the " wide cavity " leading from vagina to uterus , described by Leuckart . In fig. 5 there is some appearance of this tube continued backwards from u ( a , fig. 5 ) , but I cannot follow it to any communication with the vagina ( va . ) . The same is true in this specimen of the ovary ( ov . ) and seminal pouch ( s.p. ) . The vitelligene glands ( e , fig. 4 ) have disappeared in fig. 5 , and the ovary has become less distinct , but the seminal pouch has developed somewhat , while in fig. 6 , taken from a sexually mature segment , the latter organ is still plainer ; the canal of the vagina has elongated , and shows besides the seminal pouch a smaller dilatation ( a , fig. 6 ) nearer the orifice . In none of the mature segments have I been able to make out any communication between the vagina and uterus , either in front of or behind the seminal pouch . Although Dr. Cobbold has succeeded in rearing a variety of tapeworms from their respective larvse , the Tcenia echinococcus has not hitherto been reared in this country . The importance of this creature in its pathological relations , and the desideratum of more information as to its anatomy , have induced me to place the foregoing facts on record . In conducting the investigation I have taken every precaution to prevent the escape and distribution of the ova and their contained proscolices . EXPLANATION OF PLATE.-Fig . 5 . va . Vagina . a. Tube ( ? ) leading from uterus to vagina . ov . Ovarium . t. Testicles . s. p. Seminal pouch . v. d. Vas deferens . u , u ' . Uterus partly developed . c. p. Cirrhus pouch . i : i:ii ? -- ? I , C , " -I . ? - ? ? ? ?--- ? ; ? i:r ? C : ? -- ? ? ? ? ? ?:i / a a/ -1 , ? ? ? ?I ? ;:\ J 'i d " i ` ; ? ? ? ? c:ii ? ? ? ? ' j ! :i -j F1 iI i : j -i. . i- : / 1 ; C ) rC ) C ) 0 C ) C ) N Cs q- , , i_::-( : i ' . i r ? r ? s. i:i ; rjd / i. . ? i r\s ? , i:'Si i ? * ? KK CZQ I.Lr3 * ' 33_ , , a--__.._ . : ? Y ; _1L ? -i . , ? - ? s ` ; ? ? ?--3 ? ' ) p ? . " ? _ ... . : ir..IS ; 'r / ? rL ' c , ? 9 ? / JJL'i - . j :
112623
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Observations on the Ovum of Osseous Fishes. [Abstract]
226
229
1,866
15
Proceedings of the Royal Society of London
W. H. Ransom
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
4
29
1,203
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112623
null
http://www.jstor.org/stable/112623
null
108,978
Biology 3
59.258204
Nervous System
16.903983
Biology
[ -64.93331909179688, 31.195051193237305 ]
VIII . " Observations on the Ovum of Osseous Fishes . " By W. H. RANSOM , M.D. Communicated by Dr. SHABREY . Received June 21 , 1866 . ( Abstract . ) In this paper the author has communicated the details of observations of which the principal results were stated in a short paper published in the Proceedings of the Royal Society in 1854 , and of further researches on the structure and properties of the egg in several species of osseous fishes . The methods employed in determining the functions of the micropyle , and in conducting the various inquiries entered upon are described . The development of the ovarian ovum is traced in two species of Gasterosteus , and the yelk-sac is shown to increase by interstitial growth , and not by apposition of layers on either surface . A minute description of the germinal vesicle and its contents is given , and the germinal spots are shown to be drops of a thick fluid substance , so apt to change their normally round form , and to vacuolate in their interior , that no perfectly indifferent medium was found in which to examine them . The primitive yelk first fbrmed around the germinal vesicle is shown to differ in some of its chemical and physical properties from that of the ripe ovum ; it is solid , and does not consist of two distinguishable portions . On its surface a yelk-sac was found in very early ova , but in the smallest eggs examined it could not be separated . The reactions of a variety of albumen allied to myosin , which the author has found in variable proportions in the yelk of all the fishes , amphibia , and birds which he has examined , are described , the yelk of the salmon being selected for experiment . This substance , to which the name albumen C. is given provisionally , is remarkable , in addition to its being easily precipitable by water in excess , for forming under certain conditions a solution in dilute nitric acid not coagulable by boiling . Some account is rendered of the reactions of an acid compound of phosphoric acid with an organic substance also met with in the yelk of various animals . The phenomena which follow impregnation prior to the commencement of cleavage are described , and are shown to be chiefly due to the influence upon the yelk of water which has passed through the yelk-sac . Some variations which occur in this respect in different species of osseous fishes are described , and the ova of Gasterosteus are shown to be remarkable il having a viscid mucoid covering derived from the oviduct , which prevents the imbibition of water through the yelk-sac , so that it only then enters and forms a breathing-chamber after impregnation , when it passes through the aperture in the apex of the micropyle ; whereas in the eggs of salmon and in those of most other fishes , unimpregnated ova rapidly absorb water by the whole surface of the yelk-sac , the yelk contracting at the same time to form the breathing-chamber . The concentration of the formative yelk , originally forming a thin layer over the whole yelk-ball , at the germinal pole is also proved to be due to the action of water , of which it requires a free supply sufficient to distend the yelk-sac , and to be independent of fecundation . The contractions of the yelk are shown to be also independent of the action of the spermatozoids , and to be reactions following the entrance of water into the breathing-chamber ; and this not only as regards the rhythmic waves , which pass over the surface of the food-yelk , but also the fissile contractility of the formative yelk , by virtue of which it cleaves into irregular and unsymmetrical masses , and which the author conceives to be regulated only by the influence of the seminal particles . The cortical layer of the food-yelk or inner sac , which is shown to resist in a remarkable manner osmosis , is found to be the rhythmically contractile part , although requiring for its manifestation the presence of acid foodyelk upon its inner surface . Evidence is given to show that the contractile property of the yelk of both kinds requires , as an essential condition of its manifestation , the presence of oxygen in the surrounding medium , and that the food-yelk , while the rhythmic waves are passing over it , consumes less than does the formative yelk , while regularly cleaving after fecundation ; also that some product of oxidation is formed during these movements , which itself tends to check them , but which the author failed to determine the nature of . Proofs are also given that a certain moderate rise of temperature increases the activity of these contractions . Experiments are related which show the extreme limits the yelk will bear without destroying them , and the temperature at which commencing chemical change prevents further contraction . The reactions of the substance of the yelk under the stimulus of galvanism are recorded , and evidence afforded that the food-yelk and the cortical layer alone are excited to contraction by it , attempts made to induce fissile or other contractions of the formative yelk resulting in electrolysis of that highly unstable substance . Experiments made to ascertain the effects produced by poisonous substances on the contractions of the yelk are recorded , and the general fact ascertained of the extreme indifference to such agents of yelk protoplasm . Carbonic acid , however , is shown to destroy the contractility rapidly , and chloroform to arrest it for a time . The process of cleavage is described , and experiments are given which show that oxygen in the surrounding medium is an essential condition of its occurrence . The influence of heat in quickening it , and the comparative indifference which it shows to the action of a galvanic current and to most poisons , are proved by a series of experiments , in which also the remarkable and destructive activity of carbonic acid is evidenced . The author has considered the egg as a cell , its contents as a protoplasm , of which the firmer cortical layer is the equivalent of the primordial utricle , and the fluid food-yelk of the liquid contents , while the formative yelk is represented by the granular accumulation around the nucleus . Two stages or grades of development of protoplasm are conceived to be represented by the two forms of yelk , and a parallelism is attempted to be drawn between them and the stages of development through which many amceboid organisms pass , and which the author believes to have a wide , if not a universal existence in the organic world ; the lower grade represented by the homogeneous food-yelk with a cortical layer , and possessed of rhythmic contractility , passing into the higher represented by the formative yelk of a granular structure , and possessed of a fissile contractile property only .
112624
3701662
Variations in Human Myology Observed during the Winter Session of 1865-66 at King's College, London
229
244
1,866
15
Proceedings of the Royal Society of London
John Wood
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0054
null
proceedings
1,860
1,850
1,800
14
367
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http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112624
10.1098/rspl.1866.0054
http://www.jstor.org/stable/112624
null
null
Anatomy 2
70.732461
Nervous System
11.498906
Anatomy
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IX . " Variations in Human Myology observed during the Winter Session of 1865-66 at King 's College , London . " By JOHN WOOD , F.R.C.S. , Demonstrator of Anatomy . Communicated by Dr. SHARPEY . Received May 3 , 1866 . In the present paper are given the results of observations , made with the greatest possible accuracy and care , of the muscular anatomy of thirty-four subjects , chiefly of the male sex , with an especial view to the study of the combinations of these abnormalities , and the directions in which they chiefly tend . To enable the reader more readily to comprehend these results , the author has tabulated them in the sheet appended to the paper . In the Table the names of the muscles placed at the head of each column refer to those in which more than one variety has been observed in the session . They will be found to correspond very closely with those given in the former papers by the author . In columns 4 , 21 , and 27 are placed those of which only one example has been met with . Some of these , however , are of much importance . To explain the nature of the abnormality more precisely than could be done in the Table , a word or two will be necessary on such of the specimens as may be considered novel or typical . Four columns are occupied by variations of the head and neck , the examples of which amount in the aggregate to twenty-two ; some of the muscles in these may , however , strictly be considered as muscles also of the upper extremity , especially those in col . 3 , which I have denominated cleido-occipital . Col. 1 . Platysma myoides.-The first of the two varieties noted ( in subject 20 ) was connected with the inner side of the lower end of the normal muscle , the fibres passing in a broad band downwards and inwards , over the origin of the sterno-cleido-mastoid , the clavicle , and upper fibres of the pectoralis major to be inserted into the fascia covering the sternum as far down as the third costal cartilage . The second ( subject 29 ) was connected internally with the sternal fascia between the second and third costal cartilages , and crossing obliquely outwards and downwards over the lower fibres of the pectoralis major and axillary cavity , became attached to the tendon of the latissimus dorsi , exactly as we find its homologue , the panniculus carnosus , to do in the lower animals . This variety of the Platysma does not appear to have been previously recorded . 2 . Digastric.-The two varieties of this muscle were found , as usual , in the anterior belly , which was double . In the first ( No. 1 ) the redundant belly was attached by the median raphb to the one on the other side , and was implanted upon the tendon in the usual manner . The second decussated with its fellow on the opposite side , and each became attached to a part of the digastric fossa on the opposite half of the mandible , as given in the author 's first paper , alud described by Henle and other anatomists . 3 . Cleido-occipital.-The author has ventured to bestow this name upon a muscle which proved , when looked after , to be so common that not less than eleven specimens were found out of the thirty-four subjects . It will be best understood by reference to fig. 7 a , in the subject of which it was found in conjunction with a sternoclavicular muscle . It is placed along the hinder border of the sterno-cleido-mastoideus , usually separated , however , by a distinct areolar interval from both the sternal and clavicular fibres of this muscle . It is attached below to the juinction of the innier and middle thirds of the upper border of the clavicle , and above to the superior curved line of the occipital bone , close to the origin of the trapezius mnisele . It is described by Meckel ( Handbuch der mensch . Anatomy , 1816 , p. 474 ) as an accessory to the sterno-cleido-mastoid sometimes met with . It may be considered as a lateral extenlsion and separation of part of the clavicular fibres of the sterno-cleido-mastoid , which , in the nlormlal arrangement , are crossed and entirely covered at the upper part by the sternal portion , and do not extend at their insertion beyond the mastoid portion of the temporal bone . The author has found that in the Guineapig and some other Rodents it constitutes a separate muscle , entirely distinct from the sterno-mastoid , carrying with it the whole of the clavicular fibres of the sterno-cleido-mastoideus . In the Dog and Cat , and probably in the other Carnivora , it forms part of the long muscle , the cephalo-hIumeral . In these animals the cleido-mastoid is a distinct muscle , joining with the cephalo-humeral at the rudimentary clavicle . In the Hedgehog , on the other hand , the cleido-mastoid is blended with the sterno-mastoid , while the cleido-occipital is placed as a distinct muscle behind it . In the Apes and Monkeys it is always present , but continuous with the hinder border of the true sterno-cleido-mastoid , with a more or less distinct intermuscular space* . The above peculiarities of its comparative anatony , and the fact of its separate attachment to the occipital bone , instead of the mastoid portion of the temporal bone , have induced the author to propose the niame here given to it . 4 . Of the single specimens in this column the levator claviculte was in most respects the counterpart to that given in the author 's last paper ; but it was found only on the left side , arising from the three upper cervical transverse processes in front of the levator anguli scapulte , and inserted into the outer half of the clavicle , behind the anterior fibres of the trapezius . On the opposite side it was not found , but a very distinct cleidooccipital was present . This again was not found on the left side , but appeared to supply the place of the levator claviculca . The costo-fascialis cervicalis , of subject 28 , was in every respect like those described in the author 's two last papers . The sternalis brutorum was a small developmenl t on the right side only , reaching from the third to the sixth costal cartilage . The rest of the muscles in this column scarcely need a more extended description than is there found . No less than seventeen out of the twenty-seven columns denoting the different kinds of variety are occupied by those of the arm , of which there are seventy-one examples . 5 . Epigastric slips of the _pectoralis major presented various degrees of development of the so-called chondro-epitrochlear muscle of the Apes and Monkeys , but reaching only as far as the insertion of the rest of that muscle into the bicipital ridge , and terminating distinctly from it . None of them were so complete in their developmenit as those described in the author 's first paper . One specimen is seen in fig. 1 a , in significant cornbination with the ape-like variation placed in the next column . 6 . The developments of the pectoralis minor given in this column are such as may easily be overlooked , but when closely sought for , as in the last session , have yielded no less than five specimens out of thirty-four subjects . The variety consists in the prolongation of the tendon of insertion as a flat tendinous slip , sometirnes connected with a large portion of the muscular fibres , over the upper surface of the coracoid process , which is grooved distinctly for its reception . This tendon then joins that of the supraspinatus muscle , and blending with it and the capsular ligament , is implanted into the upper facet of the greater tuberosity of the humerus ( see fig. 1 6 ) . In the subject of the sketch ( a female ) aniother tendinous slip was directed upwards and outwards , and lost upon the coraco-acromial ligament . The insertion of the pectoralis minor into the shoulder-joint capsule is mentioned by Meckel ( op . cit. p. 467 ) , giving Gantzer as his authority * . This prolongation of the tendon to the humerus reaches to a greater extent in the Monkeys in proportion to the diminution in size of the coracoid process . In the Carnivora it is entirely inserted into the greater tuberosity , and blends more or less intimately with the pectoralis major . In subject 22 the upward direction of the insertiork of the pectoralis minor becomes more marked as an insertion of the upper muscular fibres into the costo-coracoid membrane and the clavicle itself . The origin of the muscle was in this case higher than usual , reaching to the first intercostal aponeurosis . This upward development of the pectoralis minor is an approximation to the condition of its insertion in the Rodents , and , as the author believes , is a formation identical with the sternoclavicular muscle , and fouind in subject 27 , column 21 ( fig. 7 ) . 7 . In this column are given two opposite tendencies of development of the latissimus dorsi . Of the first are those not uncommon slips of communication between this muscle and the insertion of the pectoralis major , passing in front of the axillary vessels and nerves ( see fig. 1 c ) , described by Meckel , Langer , and Gruber ( Achselbogen ) . The author re* De Souza describes a case in which the whole of the peceoralis minor was inserted into the capsuLle of the shoulder-joint ( Gazette Medicale , 1855 , No. 12 ) . gards these as imperfect developments of the so-called dorsi-epitrochlear muscle of the lower animals . None have been found this session extensively developed , and these only in three subjects , of which the last ( No. 32 ) was one remarkable for the num-lber of its muscular abnormalities . The other varieties found were two specimens of the remarkable offset sent from the latisssimus uipwards towards the coracoid process , which the author described in his paper read two years ago to the Society , urnder the name of the chondro-coracoid muscle . It arises with the upper costal fibres of the latissimus from the ninth and tenth rib-cartilages , asceniding so as to cross the axillary cavity obliquely outwards . In the specimen figured in the author 's first series it was inserted with the.pectoralis minor into the tip of the coracoid process . In subject 10 ( fig. 2 ) it is inserted partly into the lower surface of that process ( a ) , and partly into the capsular ligament of the shoulder with the tendon of the supra spinatus ( b ) . It will be observed to pass between the trunks of the axillary plexus , separating the posterior from the lateral cords . The latter and the vessels are cut to show the musele . In subject 28 this muscle was connected with the origin of the coraco-brachialis , and passed with it to the tip of the coracoid . A similar slip of muiscle , passing from the 5th , 6th , and 7th ribs to the muscles connected with the coracoid process , was observed by Theile ( Jourdan 's Translation , p. 204 ) . In all the specimens the unvarying origini of this curious slip , and its relation to the one which joins with the insertion of the pectoralis major , and to the chondroepitrochlear muscle of the lower animals , show it to be the result of an upward displacement of the same typical structure , ranging from the insertion of the pectoralis major to that of the pectoralis minor . 8 . The increased number of the heads of the biceps in the two subjects in this column were of the more usual kind described by Meckel and others , arising from the fibres of the brachialis anticus and from the greater tuberosity of the humerus . 9 . In subjects 14 and 17 the 6rachialis anticus presented a continuiity of a large portion of its outer fibres of origin into those of the supinator longus , which is not uncommon , althoughi not , as far as the author is aware , previously noted in the humani subject . It is a very common arrangement in the Apes and Monkeys , assisting them very materially in climnbing and twisting the body while hanging by the anterior extremities . In subject 30 there was a brachio-fascialis or quasi-third head of the biceps , simriilar to that described in former papers . On the opposite arm was found a curious fusiform muscle , springing high up from the brachialis anticus , and connected below with the pronator radii teres towards its insertion . 10 . The flexor sublimis digitorum in subjects 5 and 13 gave off on the outer side of its coronoid origin a separate slender tendon , which became the sole origin of a first lumbricalis muscle . In both , another first lumbricalis was given off from the usual place on the indicial tendon of the , pe)forans . In No. 13 also a curious division of the abnormal lumbricahls occurred , into two parts , 'of which the innermost was implanted upon the tendon of the pe^foratus , near its division within the sheath of the index finger ; while the outermost joilned the normal lumbricalis near its usual place of insertion . Higher up in the arm another muscular slip connected the redundant tendon from the su6limis with the indicial tendon of the profundus . In subject 9 was a muscular coninexion of the flexor sublimis with the origin of the flexor longus pollicis , like that described in the last paper . 1 1 . The variations of the flexor _profundus digitorum in three subjects consisted merely in a not uncommon distinct and superficial muscular origin from the coronoid process along with the fibres of the sublimis , such as is frequently met with in the lower animals . In subject 8 was found a tendon connecting the indicial part of the flexor mpofundus with the tendon of the flexor longus pollicis . In subject 20 this arrangement was reversed , the tendon going from the flexor pollicis above to the flexor profundus below . This variety is found in the next column . 12 . In addition to the variety just mentionied the flexor _pollicis longus gives , in subject 2 , a tendon to the first tumbricalis on both sides . 13 . The lumbricatles have been found irregular in three other subjects besides those just mentioned , in which the first was seen to arise from the flexor sublimis and flexor lonagus pollicis . In subject 5 the third lumbricalis on the right arm was bifurcated , one half going to the ulnar side of the middle finger and the other to the radial side of the ring finger . Both sides of the long finger were thus provided with this muscle , an arrangement which was repeated in both the hands of the 22nd subject . On the right arm of the 32nd subject the whole of the third lumbricalis ( see fig. 3 c ) was inserted into the inner side of the long finger , while the fourth was entirely absent . This was also the case with the left arm of subject 5 . 14 . The name at the head of this column-flexor carpi radialis brevis -I have applied to a muscle which is given in fig. 3 a , drawn from subject 32 . This subject was , from the number and character of its varieties , the most remarkable of the whole . In this case the muscle arises from the middle third of the front surface of the radius , between the flexor tongus pollicis above ( d ) and the pronator quadratus ( e ) below . Passing under the annular ligament as a distinict rounded tendon , close to the carpal bones , inside of and parallel with the sheath of the tendon of the flexor carpi radialis ( f ) , it is inserted partly into the os magnum , but chiefly into the base of the middle metacarpal bone , where it gave attachment to some fibres of the fexor brevis pollicis muiscle . It is evidently a flexor of the third metacarpal bone , corresponding to the flexor carpi radialis of the second metacarpal . During the last session a precisely similar muscle was described by Dr. Nortoni , of St. Mary 's Hospital , and exhibited by him at a meeting of the Zoological Society . The subject of figure 3 is further remarkable for a distinct slip of tendon from the flexor carpi utnaris ( y ) to the base of the fourth metacarpal bone ( seen at b ) . In this arm we have , therefore , a flexor for each of tne metacarpal bones , reckoning the opponens as one . But further than this , the outer fibres of the extensor ossis metacarpi pollicis in the same arm ( see fig. 6 c ) are separated from the rest by a cellular interval , and arise partly from the fascia covering the radial extensors and supinator longus . They are connected with a distinct tendon , which is implanted into the front part of the outer border of the base of the first metacarpal bone . Traction upon this tendon showed that its action was rather of the nature of flexion with abduction than of extension . This peculiarity of origin is noticed by Henle ( Muskellehre ) . The arm from which figs. 3 and 6 were taken is now in the custody of the Curator of the Hunterian Museum . In fig. 3 is seen also the abnormal insertion of the third lumbricalis ( c ) , the absence of the fourth , and at h the first palmar interosseus of the thumb , described by Henle . In fig. 6 the additional special extensors of the third and fourth fingers are given . In subjects 13 and 31 were found muscles which are entirely homologous with the flexor carpi radialis brevis just described . They had exactly similar origins , were of the same shape and with like tendons , but were iniserted into the inner side of the base of the second instead of the third metacarpal bones , one of them passing , with the tendon of the fexor carpi radialis , through the groove in the trapezium and annular ligament , but the other goinrg outside of that sheath . In subject 6 was found a large fusiform muscle , having its origin from the radius outside of that of the flexor longus pollicis , and reaching as high up as the oblique line below the flexor sublimis . Ending in a distinct , strong , and rounded tendon , it was implanted into that deeper portion of the annular ligament which separates the groove for the flexor carpi r adialis tendon , and with this into the trapezoid , magnum , and base of the middle metacarpal bones . A muscle precisely similar to this was described by the author in his last paper ( subject 1 ) . Its resemblance in appearance , position , connexions , and influence upon the carpus , have induced him to class it with the foregoing flexor carpi radialis brevis as a variation of the same type of muscle , the flexor of the middle metacarpal bone . 15 . The variations of the radial extensors found in this column are of two kinids , which appear to be closely allied . The first kind mentioned are the interchanging muscles frequently seen and recorded by anatomists . These , arising with one of the twin muscles , pass as distinct tendons over to the other , and become inserted with it . Of these , three were found . In the absence of a name the author has ventured to distinguish this form of muscle by that of the extensor carpi radialis intermedius . Of the other kind is found only one example . It is the extensor carpi radialis accessorius first recorded , named and described by the author in his former papers* . It has been chosen as the subject of fig. 4 , taken from the right arm of subject No. 23 , because of its coexistence with the intermediate form of the radial extensors , which was not the case in any of the specimenis before found . It arises from the condyloid ridge of the humerus , below the extensor carpi radialis longior ( f ) , lies between that muscle and the extensor intermedius ( c ) , which separates it from the extensor carpi radialis brevior ( d ) . It has a distinct tendon of considerable size , which , crossing that of the longior , goes through the sheath of the extensors of the metacarpus and first phalanx of the thumb , and divides into two slips , one to be implanited into the base of the first metacarpal , and the other to give part origin to a double abductor jpollicis ( b ) . The tendon of the intermedius ( c ) can be seen to be implanted upon the second metacarpal with that of the longior . In the left arm of the same suibject only the intermediate form was found . The close relation of these two forms is well seen in the figure . The accessorius has an origin somewhat similar to the intermedius , while its insertion and connexion with the short abductor is precisely similar to that often found in the tendon of extensor ossis metacarpi pollicis , with which the radial extensors have usually so close a connexion at its origin , as before alluded to in describing the redundancy of that muscle in subject 32 ( fig. 6 c ) . If we suppose the germ of an extensor intermedius to become blended with that of the upper and outer portion of a double extensor ossis metacarpi pollicis , the result would be the extensor accessorius here described * . 16 . The extensor ca ? pi ulnaris in two subjects sent , in both arms , tendinous slips to the little finger , which were blended with the common extensor aponeurosis ( fig. 5 a ) . This variety is mentioned by Meckel . Henle conisiders it as homologous with that of the peroneus quinti in the foot . In both subjects the arrangement of the slip was strikingly similar to that of the last-named abnormality , but in neither of them was the peroneus quinti found in the foot . In the same arms the extensor minimi digiti ( b ) was found provided with two tendons , both inserted , with a slip from the common extensor , into the dorsal aponeurosis of the fifth digit ( c ) . 17 . In three other subjects , besides the two last mentioned , the extensor miniani digiti was found to have a double tendon . In one the muscle also was doubled . In subjects 5 and 32 the outermost of the tendons of this double muscle was inserted into the extensor aponeurosis of the ringfinger , thus forming a special extensor of this digit ( fig. 6 a ) , joining , before reaching it , with a slip from the common extensor , which directly afterwards again left it , carrying some of its fibres to join the little finger . This arrangement was described by the author in his first paper , and has been also noticed by Vesalius , Meckel , and Hallett in Man , and by Church in the Apes . 18 . In this column are found two specimens of that differentiationof the extensor indicis m'nuscle which results in a proper extensor of the middlefinger . In fig. 6 ( taken from the extensor aspect of the same arm as fig. 3 , subject 32 ) is seen a complete double set of extensor tendons for each of the five digits , in addition to the interesting varieties found on the flexor side ( including a whole set of flexors for the fivemetacarpal bones ) , and in other parts of the body . It was not found in the left arm . In subject 13 , the extensor medii digiti was found in both arms , and , what is significant , it was associated in both with the fexor ca'pi 'adialis brevis before described , showing a special tendency to development of the muscles of the middle digit . A similar tendency is shown in subject 15 , by a duplication of the tendon of the indicator , both tendons in tnis case being inserted inlto the first digit . 19 . Of the extensor brevis digitorutm manus , described in the author 's last papers , fewer examples than usual have been found , none of them very complete . In subject.32 a single slip to the middle finger is founid associated with theproper extensor and aflexor of the metacarpal bone of that digit ; a combination which was present also in the rernarkable subject ( 1 ) described in the last paper , and , with the exceptionl of the proper extensor , in one other subject last session . It may be taken as a further proof of the specializing ten-cdency in the middle finger in this subject . 20 . Of the interossei , five specimens of differeltiation are nioted , chiefly belonging to the first , or abductor inclicis . Two specimens of a palmar interosseus of the thumb are found in Nos. 5 and 32 , both presenting numerous other variations . 21 . Among the miscellaneous muscles of the armi the most noteworthy specimen is that of a sternoclavicuzlar muscle , similar to that described by Haller , and more recently by Mr. Berkeley Hill . This muscle ( given in fig. 7 c , from subject 27 ) arises by a thin tendon from the front of the manubrium sterni , just below the origini of the sterno-mastoid . Spreading as a muscular layer upwards and outwards under the clavicular fibres of the pectoralis major ( b 6 ' , cut and turned up in the figure ) , it is inserted into the lower border of the clavicle , just in front of the subelavius muscle , from which it is separated by the costo-coracoid miembrane ( a ) , extending nearly as far outwards as the origin of the dleitoid . This muscle has been found in Birds , Bats , and Moles . The author has also found it remarkably well-developed in the Guineapig and some others of the Rodentia . HIe believes it to be closely allied to the upward extension of the pectoralis minor , before alluded to , and to result from a differentiation of such an upward extension . In the subject of the sketch it was associated with a cleido-occipital ( a ) , and with an increase in the number of tendons to the little fing , er . In subject 26 was a curious muscular slip extending behinid the axillarv vessels and nerves , from the insertion of the subscapular muscle to the fascia covering the long head of the triceps , and derived from the tendoln of the latissimus dorsi . Apparently this is an imperfect form of development of a short coraco-brachialis muscle , such as that described in a former paper . In subject 13 was a high fascial origin of the abductor minimi diyiti , from the lower third of the forearm , like that described and figured in the author 's first series . This has been observed by Gulnther ( Chirurgische Muskellehre , Taf . xx . Fig. V. 18 ) . A double abductor pollicis brevis was found in three cases , besides that in which it was connected with a slip from the extensor carpi r adialis accessorius ( given in fig. 4 ) . In subject 23 , and also in 32 , was a double extensor ossis metacarpipollicis , the tendon of one being inserted entirely into the annular ligament and origin of the abductor pollicis . The rest of this column scarcely lneeds further description . The six remaining columns are occupied by abnormalities of the muscles of the leg , of which there are thirty-nine examples . 22 . Peroneus tertius.-Two out of five anomalies in this column result from the total absence of this characteristically humani muscle , giving a very ape-like appearance to the foot . In No. 7 it was absent on the right side only ( see fig. 8 ) , in No. 16 on both sides . In subjects 11 and 32 a distinct tendinous slip from it was implanted into the base of the fourth metatarsal . In another , the tendonl was doubled , though both were inserted into the fifth metatarsal , spreading towards the fourth . 23 . Peroneus quinti . In three out of five specimens foutnd , this tendinous slip from the peroneus brevis to the extensor aponeurosis of the little toe was perfect , as described and figured in the last paper . In the remaining two , the tendinous slip from the brevis , instead of reaching the toe , became implanted upon the upper border of its metatarsal bone , near the front end ( fig. 8 a ) . In both cases this slip supplied the place of the peroneus tertius , which was totally wanting , except in the left foot of subject 7 , in which both the slip and the muscle was present , though small . In the subject of the figure the peroneus brevis tendorn gives also a slip of origin to a bundle of muscular fibres which joiln the abductor minimi digiti as a separate muscle ( b ) on the outer side . This is a somewhat similar arrangement to that of a specimen given in the author 's first series , in which the peronetus quinti was provided with a separate muscular belly on the outer border of the foot . tOL . X , 24 . The extensor longus primi internodii hiallucis , described in the author 's first paper , was found in no less than ten out of the thirty-four subjects , in all , except one , in both legs . In seven the muscles and tendons were fully developed and distinct from the fibres of the extensor proprius hallucis , generally arising above , but sometimes below this muscle . In the remaining three ( Nos. 11 , 19 , and 21 ) the abnormal muscle was represented by a tendon given from the extensor proprius near the ankle . In subject 21 this tendon was also , on the right side , contributed to by one from the extensor longus digitorunm . In all the tendon was attached to the base of the first phalanx of the great toe , close to the joint , either distinct from or in union with that from the extensor brevis di.gitorum pedis . 25 . Flexor longus accessorius.-The high origin of this muscle , by an additional head from the lower third of the fibula , or from the fascia covering the flexor longus hallucis , has been observed in three cases . In all it was provided with a distinct tendon , which joinied separately in the union of the long flexor tendlons in the middle of the sole . In subject 26 the flexor accessorius was made up of four distinct heads . 1 . The long head as above described ; 2 , another tapering fleshy belly from the upper part of the os calcis and insertion of the plantaris tendon , in front of the tendo Achillis , and ending in a distinct tendon ; 3 , the usual " massa carnea " from the hollow surface of the os calcis ; and 4 , the outer tendinous slip from the lonig plantar ligament . These all uniting , joined with a large slip from the tenidonr of the flexor longus pollicis , to form a distinct deep or third set of flexor tendons passing to the four outer toes . Each of these joiined that of the _pe forans in the inside of the sheath , about the first joint . 26 . Abductor ossis metatarsi quinti.-This muscle , as described and fig , ured by the author in former papers , was found only in sev-en subjects this session , in all in both feet . This is much less than the proportion found last session . In two out of the five females dissected , they were found well developed , of a fusiform shape , arising from the outer tubercle of the os calcis , and inserted by a distiniet rounded tendon into the base of the fifth metacarpal bone . In five males only , out of the twentynine dissected , were they found as muscles distinct from the fibres of the a6ductor minimi digiti . In the previous session the proportion of female subjects to males was very much greater than in the last . The specimens of this muscle found were also much more numerous , so much so as to be estimated by the author at nearly half the number of subjects . Whether this remarkable difference depends upon the sex , or is accidental , must be decided by future observations . 27 . In the miscellaneous column we have nine single speciinens , as compared with eleveni or twelve in the arms , and six or seven in the head and neck . In a female ( 31 ) was an areolar separation of the front fibres of the gluteus minimus forming a scansorius muscle , like that described in a former paper . In subject 30 the peforatus tendon of the little toe was derived from the fexor accessorius , as seen also last session . In subject 7 , the same tendon is derived from the fifth tendon of the pe ? :forans , as found in the Apes and Monkeys . The two last appear to be , respectively , the imperfect or transitional , and the complete stages of this significant change . Two varieties , which I have not found ' recorded by any anatomical writer , were noticed in subjects 12 and 26 . In the former the abductor hallucis , and in the latter the flexor brevis hallucis sent a considerable muscular slip to the base of the first phalanx of the second toe . In the former the slip passed deeper than the transversuspedis muscle , and in the latter superficial to it . In subject 25 the third lu ? nbricalis took origin from the tendoni of the pe ? foratus instead of the pe ? forans , presenting an analogue to the origin of the first lumbricalis in the hand from a tenidon of the flexor sztblimis pe ? foratus in subjects . S ) and 13 . In subject 2 the fourthl plantar interosseuts arose f om na slip of the tendoll of the 2er oneus lotgucs , as in the instance descr ibed and figuired in the author 's last paper . In subject 16 was a cuir'ious double origin of the tdducetor 7ongusfenmoris , the abnormal hea(l arising with the fibres of the pectinels . In reference to the comnlbina(tionls of the above muscular variations an inspection of the Table will show the following points:-First , that only in two subjects out of the thirty-fouir examined were nto muscular abniormalities found ; i. e. nio deviations from the ordinalry type sufficiently striking to be recorded . It is , indeed , hiighly probable that variabilities of every kinid arc limited only by the possibilities of the permutations and combinations of the Wholc of the structuires of the humnan bodvr . It will be observed also that the grent majority of the abnormalities welC s. ? n ? etricwa , or fouInd on both sides . , Secondclq , that of the total number of muscular variations , 132 ( not reckoning both sides when alike ) , 71 , or more than one half , are found in the arms . If we reckon with these those muscles which , thontgli founlid in the nieck , act ehiefly upon the clavicle , a boon of the upper extremity , viz. the cleido-occipitael and the levatorv clavictlae , Xwe shall have 12 more to add to the 71 , increasing the proportioni of the arm muscles , and diminishing those proper to the head and neck to 10 . The number of abniormalities in the legs amount to 39 , or rather more than half the number of those in the arms ; while in the abdomen and lower part of the trunk not onIe is recorded , though , of course , some may have escaped observation . Thicrdly . The greatest number of abnormalities combined in the same individual is 14 ( in subject 32 ) , a very muscular male , in whom the proportions are 10 in the muscles of the arms ( including the cleido-occi ital ) 3 in those of the legs , and 1 only in the hcad and neck . The similarity betweeni this subject and No. 1 of the last year 's paper is remarkable . In the latter the number of departures from the ordinary type was 16 , of x which all except 7 were found in the arms ( including the levator claviculce ) , 5 in the legs , and 2 in the bead and neck . With the exception of the levator claviculce , costo-fascialis , and supra-costalis , found in the last-mentioned subject , but not in No. 32 , the correspondence ( especially in the arms ) between the different linwes of abnormal departure also is sufficiently close to become significanit , as the reader will have gathered in going through the preceding , pages . In subject 4 of the Table , which presented the only specimen of the levator claviculce founid this session , oiily one other abnormality was found , viz. the abductor of the fifth mnetatarsal bone . This was also founid associated with it in last year 's subject , which presents otherwise a marked colntrast in the niuimber of its abnormalities . In Nos. a and 7 , the one a male and the other a female , there are nine variations respectively , of which , in No. 5 , there is but one which is not in the arm ; and in No. 7 , four in the legs and three in the arms . In No. 2 are eight abniormalities , of which six are in the arms and the rest in the legs . In No. 26 are found seven , of which three are in muscles belonging to the upper extremity , and four in the legs . In No. 13 are six , all in the arms . In thirteen subjects none were found in the legs ; and in four they were found in the legs only , to the extent , in one case , of four examples ; and in all four subjects highly characteristic . None were found in the head , neck , or trunk only* . The extent of correspondence in combination of varieties in the subjects arranged in theTable(taken in the horizontal lines ) cannotbesaid to be striking . The variations seem to crop out here and there withouit much reference to each other . This may , however , be partly owing to the comparatively small number reviewed , and we should scarcely be safe indrawing deductions from it before a much greater number of subjects are treated in a similar way . The correspondence seems to be the greatest in the arm and hand , which here also assume a prominence over the rest of the frame . This , however , may be due to the ereater number of instances found in the upper extremity . The figures which are placed at the end of each line in the Table refer to the number of varieties recorded in each entire subject . Those at the bottom of each column refer to the number of each variety of niuscular abnorrnality . EXPLANATION Of the Abbreviations and References in the Table . R. Indicates the right side of the body on which the abnormality was found . L. Indicates the left side of the body on which the abnormality was found . 'B . Inldicates both sides of the body oI which the abnormality was found . a. Detached muscular slip from 6th cartilage , with separate insertion into humlerus . Also in No. 5 . b. Muscular slip from latissim^-us dorsi to insertion of pectoralis mno , jor . Also in Nos. 5 and 32 . c. Tendon from flexor longus pollicis , giving origin to first lumbricalis . d. Single muscle with two tendons , both inserted inlto little finger . Also in Nos. 9 , 25 , and 27 . e. 14almnaris longus , with belly of muscle below instead of above . f. Fourth plantar interossetes arising from tendon of peroneus longus . fq . Extensor carpi radialis internmcdi4us arising ( muscular ) with lonigior , and inlser ted tendinous with brevior , or vice ver sd . Also in No. a , and the right side of No. 21 . A. Pectoralis minor , giving tendinous slip to greater tuberosity of humerus ; joilling with the tendon of sulpraspinatus and capsular ligament . i. ( Riglit side ) third izmbricalis bifurcated to opposed sides of middle and ring-flngcr . ( Left side ) no lumbricalis to little finger . Also seen in No. 22 . j. Extensor minimii digiti gave a teindoni to the ring-finger on both sides . Also in No. 32 . k > . A first palnar interosseous ( of ilenlo ) , under flexor brevis to pollex . 1 . Flexor carpi radialis brevis , vel profundus , as a , ftisiform muscle , arising from the oblique line of radius , and inserted into the annular ligament . us . DouLble anterior belly of digastric , decussating across the median line . ni . Muscular slip from complexus to r-ectus capitis posticues olqjor . o. Detached miiuscular slip from epitrochlea to olecranoil over ulnar nerve . Ip . Tendinous slip from peroneus brevis to uipper border of fifth metatarsal . q. Flexor longus accessorius nuscularl head arose from deep fascia covering flexor longus digiti . r. Perforatus tendon of fifth toe arose from tendon of perforans . s. Double stylo-pkharyngeus , one behind the other . t. Detached slip of pectoralis inajor , arising from abdominal tendon at epigastriuln , and inserted separately into tendon at humerus . Also in Nos. 9 and 32 . 2c . Tendinous slip prolonged from extensor caspi ulnaris to extensor tendon of little finger . Also seen in No. 27 . V. Detached slip from latissimus dorsi a.t ninth rib , to coracoid process at insertion of pectoralis minor ( chsondro-coracoid ) . wo . Extensor longus primi ineernodii hallucis , arising from fibula and interosseous ligament above extensor proprius hallucis . Also in Nos. 18 , 24 , 25 , 26 , and 30..x . Tendinous slip of insertion of peroneus tertius to base of fourth metatarsal , as well as its usual insertion into the fifth . Also in No. 32 . y. Exteensor longus_prini internodii hallucis tenidon given off from that of extenlsor _proprius hallucis . Also in Nos. 19 and 21 . z. Abductor hallucis sent a large slip to base of first phalanx of second toe . a ' . Muscular slip from coronoid process to flexor profundus digitorum . Also in the two next notices in the same column . b ' . A distinct and separate extensor of the middle digit : in the next notice in the same column the indicator had two tenidolns , both inserted into the forefinger , High origini of abductor minimi digiti from fascita of forearm . d7 ' . Muscular slip connecting the brachialis aenficzts with the.supineior lo ? guse . Also in the next notice in the same columni . c ' . Suvperficial slip connecting the two portions of flexor brevis Ipoliicis . ' . Origin of stylo-glosstus fromii the angle of the lower jaw . g ' . Subcutaneous slip from sternal fascia to cervical fascia . h ' . Musculo-tendinous slip from flexor pollicis 1i2oGus to inclicial portion of profundu . i ' . Flexor car:pi radialis accessorius , a separate muscle connected with tho origin of longior , to be inserted into the base of the metacarpal of 2ollex , giving a slip to abductor pollicis . k ' . Slip of pectoralis minor inserted into costo-coracoid membrane and clavicle . 1 ' . Double muscle , the lower inserted into annular ligament and origin of abductor pollicis & in ' . Flexor lonzgus halluscis exchanged slips with flexor longus dligitorze7n . n ' . Third lusnbricelis arose from ftlxor perforatus instead of p)erforans . o ' . Flexor brevis hallucis sent a largo slip to base of first pha.lanx of second toe . p ' . MIIscular slip from insertion of subscapularis to the n.leck of the humerius and tendon of ltcdissimus , an imperfect coraco-bi rehiclis brevis . q ' . A distinct muscle from front ; of maniubrium to lower border of clavicle , under -fibres of p)ectoralis mqcaor ( Sterno-claviculai- ) . Subelavius also present . r ' . Distinct muscle arising from first rib with sterno-thyroid , and insert ; ed into cervical fascia under sterno-cleido-mastoid ( costo-fcasci(elis cervicalis ) . s ' . Muscular slip from latissimvus dorsi to join coraco-brachialis just below coracoid process , across the vessels of the axilla . t ' . On the left side a miiuscular slip from brachiialis anticus to the fascia of the forearm ; on the right side ai . fusiform muscle forming a high origin of thepronator rad . teres , it ' . Perforatus tendon of little toe from flexor accessorius . e ' . Muscular slip from sp lenius colli to serratus m ; 9agnus . w ' . Thircl lumbricalis to inner side of middle finger . Fourth absent altogether . ' . First dorsal interosseus double . Also in 27 . y ' . Tendinous slip from ftexor carpi utnaris to base of fourth , as well as the fifth metacarpal x ' . Separationof anterior fibres of gluteus minimzes , forming distinct muscle .
112625
3701662
On the Muscular Arrangements of the Bladder and Prostate, and the Manner in Which the Ureters and Urethra Are closed. [Abstract]
244
249
1,866
15
Proceedings of the Royal Society of London
James Bell Pettigrew
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
6
76
2,795
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112625
null
http://www.jstor.org/stable/112625
null
null
Neurology
80.854548
Biology 2
15.639251
Neurology
[ -68.59619903564453, 11.569440841674805 ]
X. " On the Muscular Arrangements of the Bladder and Prostate , and the manner in which the Ureters and Urethra are closed . " By JAMES BELL PETTIGREW , M.D. Edin . , Assistant in the Museum of the Royal College of Surgeons of England . Communicated by Dr. SHARPEY , Received June 21 , 1866 . ( Abstract . ) The present communication , which is based on an extensive series of dissections* and illustrated by photographs , is intended to show that the muscular fibres of the bladder , contrary to the received opinion , are spiral fibres , and with few exceptions form figure-of-8 loops . The loops are variously shaped , according as they are superficial or deep , the more superficial loops being attenuated or drawn out so as to resemble longitudinal or vertical fibres , the deeper ones being flattened from above downwards , and resembling circular fibres . These loops are directed towards the apex and base , and are arranged in four sets ; an anterior and a posterior set which are largely developed , and a right and left lateral set which are accessory and less fully developed . The bladder is consequently bilaterally symmetrical . The superficialloops are confined principally to the anterior , posterior or lateral aspects , but the deeper ones radiate and expand towards the apex and base , so that they come to embrace the entire circumference of the bladder in these directions . The expansion of the fibres is greatest towards the apex , and the aggregation of the terminal loops of the anterior and posterior fibres at the cervix ( assisted by the lateral fibres ) form a wellmarked sphincter vesicae in this situation . The fibres pursue definite but varying courses , those which are longitudinal or vertical at one point becoming slightly oblique at a second , oblique at a third , and very oblique or transverse at a fourth . The fibres consequently change their direction and position on the vesical parietes gradually and according to a fixed principle . The principle involved is readily explained . The most external and most internal fibres are always the most vertical and most feebly developed ; those which succeed or follow becoming more and more oblique and stronger and stronger . The fibres from this circumstance are divisible into two orders , viz. , an external and an internal , and these , as has been stated , are grouped in two principal and two subsidiary sets . The two principal sets occur on the anterior and posterior aspects of the viscus , and are so arranged that the terminal or transverse portions of the anterior set intersect the more vertical portions of the posterior set nearly at right angles and the reverse . Similar remarks apply to the subsidiary sets . Between what may be called the vertical or longitudinal and the circular or transverse fibres , other fibres having different degrees of obliquity occur . These consist for the most part of the deeper anterior and posterior spiral fibres , and of the subsidiary spiral fibres from the sides . There is consequently no part of the vesical parietes in which longitudinal , slightly oblique , oblique , and very oblique external and internal fibres may not be found . The additional strength ; secured by this arrangement cannot well be estimated . The external and internal fibres are similarly disposed on the anterior , posterior , and lateral aspects , and if the dissection be conducted from without inwards , the fibres first removed are the mesial , vertical , or longitudinal fibres ; then the slightly oblique fibres inclined on either side , and crossing at acute angles as in an attenuated figure of 8 ; then the oblique fibres , crossing at wider vertical angles as in the more perfect figure of 8 . Lastly , the very oblique fibres , crossing at such obtuse angles as to have been , up to the present , regarded as circular fibres . The fibres which are still deeper and which constitute the proper internal fibres , have a precisely similar , arrangement , but are rudimentary , and consequently not so readily traced . The external and internal fibres , as will be seen from this description , be1866.3 245 come more and more oblique , both from without and from within , or in proportion as the centre of the vesical parietes is reached , the deepest or most oblique external and internal sets forming , by the blending of their terminal or transverse portions , what is commonly known as the central layer . The most external or superficial fibres are connected directly and indirectly with the slightly oblique external fibres , the slightly oblique with the oblique , and the oblique with the very oblique . The very oblique external fibres , on the other hand , are connected with the oblique internal , these in their turn being connected with the slightly oblique internal , and the slightly oblique internal with the longitudinal or vertical internal . In some instances the longitudinal external are connected directly with the longitudinal internal , and so of the slightly oblique , oblique , and very oblique external and internal fibres . The apex and base of the bladder are similarly constructed , and resemble in their general configuration the other portions of the vesical walls ; i. e. , they are composed of longitudinal or vertical , slightly oblique , oblique , and very oblique or circular fibres which cross in given directions on the external and internal surfaces . The four sets of longitudinal or vertical fibres have a crucial arrangement at the apex and base , and the slightly oblique fibres are drawn together at the urachus and cervix by the constrictions which in the embryo separate the bladder from the allantois and urethra . The slightly oblique fibres consequently converge towards the apex and base respectively ; and this arrangement at the cervix greatly assists in closing the urethra , as the fibres naturally come together to form an impervious fiunnel-shaped projection which is directed downwards and forwards . The closure of the urethra is completed by the contraction of the very oblique or circular fibres forming the sphincter , and by the prominence of the uvula vesicee ( luette vesicale ) and median ridge in the female , and the caput gallinaginis or verumontanum in the male . The longitudinal or vertical , slightly oblique , oblique , and very oblique external and internal fibres at the base are continued forward within the prostate to the membranous portion of the urethra , and the external and internal surfaces of the corpus spongiosum . The coats of the urethra are therefore to be regarded as the proper continuation of the walls of the bladder in an anterior direction . The longitudinal or vertical , slightly oblique , oblique , and very oblique spiral fibres which form the tunics of the bladder and urethra are curiously enough repeated in the prostate of the male , and the analogous structure n the female , so that this gland would seem to be composed chiefly of fibrous offsets from the fibres in question . The relations existing between the prostate , urethra , and cervix of the bladder are best seen when vertical , horizontal , and antero-posterior or transverse sections of the bladder and prostate are made . In such sections the external longitudinal or vertical anterior , posterior , and lateral fibres are seen to pass forward on the external surface of the 246 urethra ; a certain proportion passing outwards to be inserted into the anterior , posterior , and lateral surfaces of the capsule of the prostate , others passing inwards or through the gland in a vertical or longitudinal and likewise in a horizontal or transverse direction . The crucial arrangement of the four sets of external fibres at the apex and base is thus clearly traceable in the prostate . Such of the external fibres as are not inserted into the capsule of the prostate are attached to the posterior surface of the pubis , the internal border of the aponeurosis of the levator any , and the fascia covering Guthrie 's muscle . The external fibres investing the dorsal , ventral , and lateral aspects of the urethra and prostate are separated by a considerable interval , thus showing that , although the relations existing between the urethra and prostate are of the most intimate description , they may nevertheless be regarded as independent . What has been said of the external longitudinal fibres applies equally to the slightly oblique , oblique , and very oblique external and internal ones , these bifurcating and distributing themselves with considerable regularity to the walls of the urethra , and the substance of the prostate respectively . The urethra and prostate are thus composed of fibres crossing in every direction as in the bladder itself . The very oblique external and internal fibres are interesting because of the very obtuse angles at which they intersect , and because they are principally concerned in forming the sphincter of the bladder , and the so-called circular layer of the prostate . The very oblique fibres , like the other fibres described , are arranged in an anterior and a posterior set , which are largely developed , and a right and left lateral set , which are developed less feebly . The anterior fibres , which are directed posteriorly , form the posterior half of the sphincter vesicee , and the posterior fibres , which have an opposite direction , the anterior . The sphincter is thus bilaterally symmetrical , and is somewhat oval in shape , the long axis being directed transversely , or from side to side . The two sets of lateral fibres , which also enter into the formation of the sphincter , intersect the angles formed by the crossing of the anterior and posterior fibres , and render its aperture more circular than it would otherwise be . This circumstance , taken in connexion with the fact that the fibres pursue a very oblique direction , has given rise to the belief that the fibres of the splhincter and neck of the bladder generally are circular fibres , which , as the author shows , is not the case . The fibres of the sphincter are best seen by inverting the bladder and dissecting from within , or by making transverse sections of the prostatic portion of the urethra in the direction of the fundus . They are most strongly pronounced at the cervix , but are continued forward on the urethra and backwards into the bladder . In the female they extend even to the meatus urinarius . The very oblique or circular fibres of the urethra are separated from the corresponding fibres of the prostate by the longitudinal , slightly oblique , and oblique fibres forming the outer half of the urethral wall and the inner portion of the prostate . The interval is particularly evident at the cervix , where the sphincter is most distinctly pronounced ; 1866 . ] 247 and here the two sets of very oblique or circular fibres have different axes . Further forward , or towards the apex of the prostate , the space gradually diminishes , the circular fibres of the gland curving in an upward direction into the verumontanum or caput gallinaginis , and blending with the circular fibres of the urethra . While , therefore , the very oblique or circular fibres of the urethra are entirely distinct at one point , they are indissolubly united at another . This is important , as it shows how the sphincter may act independently of the prostate , and the reverse . The longitudinal or vertical internal fibres posteriorly , connect the median or central portion of the trigone ( trigone vesical , trigonum vesicEe , Lieutaud ) with the verumontanum in the male , and the uvula and median ridge in the female . The slightly oblique internal fibres bound the trigone laterally , and are continued into the verumontanum , where they cross slightly . The oblique fibres which assist in forming the base of the trigone , are likewise continued in a downward direction on the verumontanum , where they cross , and are mixed up with the continuations of the very oblique fibres which form the sphincter at the neck , and with the circular fibres of the prostate . The arrangement of the fibres in the trigone resembles that found at the cervix and fundus generally , and the author is of opinion that Sir Charles Bell was in error when he described the " I muscles of the ureters " as separate structures . The ureters enter the vesical parietes at a very obtuse angle , and the angle increases according to the degree of distension of the bladder . These tubes receive accessions of fibres from the longitudinal , slightly oblique , oblique , and very oblique external and internal fibres of the bladder in their vicinity , and are continued upon each other within the bladder in the form of a strong transverse band . The transverse band which connects the ureters together within the bladder , or between the uretral orifices , is equal in volume to the ureters themselves within the vesical parietes . The band in question is best seen when the base of the bladder is detached and held against the light , and seems to be formed by the obliteration of the uretral tubes between the uretral orifices . The uretral channels seek the internal surface of the bladder even more obliquely than the ureters , and the inner walls of the ureters become so thin , particularly towards the uretral orifices , that they act mechanically as moveable partitions or valves , as in the smaller veins* . The canals of the ureters are consequently closed , partly by the contractions of the muscular walls , and partly by the mechanical pressure exercised by the urine about to be expelled . From the foregoing description it will be evident that the various sets of external and internal fibres forming the bladder , urethra , and prostate are antagonistic , not only as regards themselves , but also as regards the territory or region they occupy ; the loops formed by the anterior fibres crossing each other at more or less acute angles according to their depths , the anterior fibres , as a whole , crossing the posterior or homologous fibres as a whole . While , therefore , the fibres , in virtue of their twisted looped arrangement , antagonize each other individually , the aggregation of the fibres in any one region check , antagonize , and coordinate a similar aggregation of fibres at an opposite point ; the anterior fibres , e.g. , acting on the posterior , and the right lateral upon the left lateral . This arrangement , which is productive of great strength , ensures that the external and internal fibres shall act in unison or together , and fully explains the views of the older anatomists , who described the bladder as consisting of fibres crossing in every direction , and forming an intricate network . It likewise accords with the more modern opinion , that the fibres of the bladder may be divided into strata or layers . The fibres , when their points of attachment are taken into consideration , can only contract spirally from above downwards , and from without inwards ; they in fact converge , or close spirally in the direction of the cervix , which may be said to diverge or open in an opposite direction as the contraction proceeds . As a result of this twisting movement , the urine , like the blood , is projected spirally* . Finally , the fibres of the bladder , urethra , and prostate pursue at least seven well-marked directions ; the fibres crossing with remarkable precision at wider and wider angles , as the central portion of either is reached , as in the left ventricle of the vertebrate heart t. In fact , the fibres of the bladder and heart have a strictly analogous arrangement , and the author is inclined to believe that functionally also they possess points of resemblance . Yery similar remarks may be made regarding the structure and functions of the stomach and uterus .
112626
3701662
Results of the Magnetic Observations at the Kew Observatory.--No. III. Lunar Diurnal Variation of the Three Magnetic Elements. [Abstract]
249
250
1,866
15
Proceedings of the Royal Society of London
Edward Sabine
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
2
18
532
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112626
null
http://www.jstor.org/stable/112626
null
null
Meteorology
59.019414
Biography
35.359598
Meteorology
[ 48.51673126220703, 7.298430442810059 ]
XI . " Results of the Magnetic Observations at the Kew Observatory . -No . III . Lunar Diurnal Variation of the three Magnetic Elements . " By Lieut.-General EDWARD SABINE , P.R.S. Received June 21 , 1866 . ( Abstract . ) The subject of this paper is the lunar-diurnal variation of the magnetic declination and of the horizontal and vertical components of the magnetic force , derived from a seven years ' series of photographic records obtained at the Kew Observatory between January 1 , 1858 and December 31 , 1864 . The discussion which it contains has for its objects-st , to exemplify the consistent and systematic character of the llnar-diurnal influence thus derived ; and 2ndly , to serve both as a guide and as an encouragement to the several establishments at home and abroad which have adopted , or are Op. cit. p. 794 . t " On the arrangement of the Muscular Fibres in the Ventricles of the Vertebrate Heart , " by the author , Phil. Trans. part iii . 1864 , p. 451 . adopting the Kew methods of magnetic investigation . The completeness of the photographic process is shown by the fact , that of 175,344 hourly positions which should have been recorded in the interval under notice , there were only 1497 failures from all causes whatsoever ; and even of these few a considerable portion is shown to be due to the employment of the instruments in other experimental investigations . The paper contains a full statement of the processes of tabulation from the photograms , and of the different stages of reduction through which the tabular results were passed , for the purpose of deriving from them the facts connected with the lunar influence on the terrestrial magnetic elements . A lunardiurnal variation is shown to exist in each of these elements , of very small amount , but having peculiar and well-marked systematic characteristics . It is further shown that these characteristics present a similarity and accordance , which it is impossible to regard as accidental , with the results obtained at several other and widely-separated localities in the middle latitudes of both hemispheres , as for example at Iobarton , Toronto , Philadelphia , Pekin , and the Cape of Good Iope . A magnetic variation shown to be thus obviously dependent upon the moon 's position relatively to the terrestrial meridian , and agreeing in its principal features in such various localities , is urged by the author as being ascribable with great probability to the direct magnetic action of the moon , made sensible at the surface of the earth through the production of phenomena which , in the present state of our knowledge as regards the magnetism both of the earth and of the moon , it is as yet difficult wholly to explain , but which are likely to lead to a considerable advance of our knowledge in both these respects . The further prosecution of the investigation , both at Kew and elsewhere , is recommended as highly deserving the attention of those who occupy themselves in the pursuits of inductive philosophy .
112627
3701662
On the Congelation of Animals
250
254
1,866
15
Proceedings of the Royal Society of London
John Davy
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0057
null
proceedings
1,860
1,850
1,800
5
65
1,876
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112627
10.1098/rspl.1866.0057
http://www.jstor.org/stable/112627
null
null
Biology 2
47.473605
Chemistry 1
22.37426
Biology
[ -76.86542510986328, -16.946931838989258 ]
I. " On the Congelation of Animals . " By JOHN DAVY , M.D. , F.R.S. , &c. Received July 19 , 1866 . In a very interesting and elaborate paper by M. Puget , entitled " Sir la Congelation des Animaux , " published in the 'Journal de l'Anatomie et de la Physiologie , ' the Number for January and February of this year , he refers to a statement of mine , made many years ago* , that the leech may be frozen without loss of life . The experiments which he has instituted , and which appear to have been conducted with great care , have led him to an opp osite conclusion , viz. that congelation is not only fatal to the leech , but to animals generally , without a single exception . He considers the cause of death , the vera causa , to use his own words , to be an altered condition of the blood . In consequence of this statement , I thought it right Researches , Physiol. and Anat . ii . p. 121 . 250 to repeat the experiments on the leech , and to extend them to some other animals . They were begun at Oxford in May , in the laboratory of Professor Rolleston , with the kind assistance of Mr. Edward Chapman and Mr. Robertson ; and since then , in the following month , they have been continued at home in Westmoreland . At Oxford the trials were made on leeches and frogs ; at home , on these animals , and on the toad and some insects . The freezing mixture was made of pounded ice and common salt ; the temperature by it was commonly reduced to below 10 ? Fahr. , or at times so low as 2 ? or 3 ? . The results obtained were briefly the following:1 . A leech was exposed to the mixture in a small glass tube just large enough to hold it , using the tube for stirring the mixture . Taken out when perfectly rigid and hard , and gradually thawed , it showed when punctured a faint indication of irritability ; there was a just perceptible contraction of the part punctured , the oral extremity , and nowhere else . It did not revive . 2 . Another leech was similarly exposed , but for a shorter time . When divided by an incision , it was found not frozen throughout . When punctured , it showed marks of irritability in a slight degree stronger than the preceding : it soon died . 3 . Two leeches were similarly treated at home , and for a somewhat longer time ; the temperature reduced to 3 ? . These , when gradually thawed , one exposed to the air , the other left in the mixture , showed no marks of revival ; but they retained a certain elasticity , so that when bent they shortly recovered their former attitude , after a manner somewhat resembling a vital movement ; but inasmuch as they did not respond by the slightest contraction to puncture , it may be inferred that the movement was not vital . They resisted putrefaction for many days . 4 . A frog in a thin glass vessel was kept in the mixture about a quarter of an hour . It was very rigid when taken out ; thawed , no part on puncture afforded any indications of life ; watched two or three hours it proved to be dead . 5 . The heart of a frog , removed immediately after decapitation , whilst still pulsating , was subjected to the freezing mixture in a small glass tube . After having been frozen , on thawing it remained motionless , even when punctured . It had been kept in the mixture only a few minutes . 6 . The inferior extremities of a frog kept extended by a bandage and thus introduced into a glass tube , were submerged in the mixture , the body of the frog being held in the warm hand ; taken out after some minutes they were quite hard and motionless , whilst the body and upper extremities did not appear to be affected . It moved about , dragging the lower extremities as if they were dead . In about four hours it recovered the use of its femoral muscles ; on the following day the use of the muscles of the legs ; the day after it was able to bend and extend these limbs ; but there was no proof that its feet had recovered sensibility . On the fourth day it was found dead . 7 . The lower extremities of a large toad were immersed in direct contact with the mixture , the temperature falling to 3 ? . Gradually thawed , the parts showed no marks of life . This toad , which before the trial was in a dull state , afterward became almost torpid , and so continued until the following morning , when it was apparently dead : opened , the auricles were found feebly acting , ceasing after a few seconds* . 8 . A similar experiment was made on the lower extremities of an active frog , and with a similar result , except that the vivacity of the animal was for a short time but little impaired : after four hours it was apparently dead ; opened , its auricles contracted when punctured . It may be right to mention that , before exposing the toad and frog to the freezing mixture in direct contact , it was ascertained that the frog bore the immersion of its lower extremities in a saturated solution of common salt without any apparent loss of sensibility or motive powert . 9 . The lower extremities of an active frog of a large size were wrapped in tin-foil , and together with one of its upper extremities not so wrapped , were kept in a freezing mixture about a quarter of an hour . The frozen parts in thawing showed no marks of life . The frog died in about three hours . 10 . A cockroach , a flesh-fly , and a minute insect , an ichneumon * ( Celineus niger ? ) , confined together in a small glass tube , were kept some minutes in the mixture . Thawed , they were found all three dead . These results , so far as the particular instances are concerned , are sufficiently confirmatory of M. Puget 's , and on my mind they leave little doubt that his general proposition ( his inference from his very numerous experiments ) is correct , that congelation is fatal to animal life . It is hardly worth while to attempt to account for the different conclusion I had come to , that referred to by him relative to the leech , it being partly founded on the fact that leeches which had been enveloped in ice for many days were not thereby killed , and partly on witnessing some marks of vitality in leeches which were believed to have been artificially frozen , and which very soon after died . Whilst admitting that congelation , thorough congelation of an animal is incompatible with life , the cause of death from congelation seems open to question , and more especially that assigned by M. Puget as the vera causa , a change in the blood , and chiefly in its corpuscles . That these corpuscles are changed by freezing in form and condition seems to be certain . Before seeing M. Puget 's paper I had ascertained the fact , and not only that the corpuscles were changed , but also that the entire blood was to some extent altered , leading me at the time to ask whether some of the injurious effects of frost-bite may not be mainly owing to the freezing of the blood , and the changes in consequence in the corpuscles and in a less degree in the fibrin t ; and since , in examining the blood of the animals exposed to the freezing mixture , I have had this confirmed ; but the change in these instances was comparatively slight ; even in those of the congealed limbs of the frogs and toad the majority of the corpuscles appeared little altered ; some few seemed ruptured , some corrugated , and more contracted . Judging from the effect of congelation on the heart of the frog in experiment No. 5 , and from the effects of congelation partially produced , as in the extremities of the frog and toad , I would rather attribute the death to the freezing of the organs , not excluding the blood , than to the freezing of the blood alone ; and I would ask , is not this view most in accordance with the pathology of the subject , with all that we know of frost-bite and its consequences in man , and with the results of Mr. Hunter 's experiments on the local effects of congelation in animals-those on the ear of the rabbit and wottle of the cock ? and do not some evenl of M. Puget 's results give it support , such as the opacity of the crystalline lens , he admitting that , were it possible for an animal to revive after complete congelation , it would be blind from cataract ? Now , if the crystalline lens , if the bloodcorpuscles suffer and undergo an appreciable change from congelation , it would be very remarkable indeed did not the brain and nerves , and the organs generally suffer from the same cause , and experience changes incompatible with life . In the instance of man , we know that a certain reduction of his temperature merely , not reaching to congelation , suffices to extinguish life * , and that in the instances of other animals , especially the hybernating and insects , a moderate reduction occasions torpor , ending in death if too prolonged . That the organs generally suffer from congelation M. Puget himself admits , as expressed in the subjoined paragrapht . I have found , too , that the muscles , after having been frozen , exhibit a marked change ; thus , in one instance , that of a frog , in which , after decapitation , an upper and lower extremity were fiozen , the muscles of these limbs , when thawed , compared with those which had not been frozen , showed a well-marked difference under the microscope . Thus , whilst in the latter the striated structure was very distinct , in the former it was no longer visible ; and after a few hours , viz. on the following morning , whilst the unfrozen muscles had undergone no perceptible alteration , those which had been frozen had become of increased tenderness , yielding to a slight rending force , and breaking short , as if the coherence of the particles forming the fasciculi was greatly diminished .
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3701662
Letter to the President from Lieut.-Colonel Walker, R.E., F.R.S., Superintendent of the Trigonometrical Survey of India
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Lieut.-Colonel Walker
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0058
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proceedings
1,860
1,850
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2
29
795
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10.1098/rspl.1866.0058
http://www.jstor.org/stable/112628
null
null
Meteorology
28.353311
Astronomy
24.102179
Meteorology
[ 33.72696304321289, 6.913691997528076 ]
II . Letter to the President from Lieut.-Colonel WALKER , R.E. ) F.R.S. , Superintendent of the Trigonometrical Survey of India . " Dehra Done via Bombay , 31st May , 1866 . MY DEAR GENERAL , -Captain Basevi has just returned to my head quarters , on the close of the operations of his first field-season with the pendulums . You will be glad to hear that his progress has on the whole been very satisfactory . At the outset he met with numerous difficulties ; the xacuum apparatus was very troublesome , the air-pump constantly getting out of order , and the receiver as constantly leaking . It is very easy for philosophers to suggest improvements and refinements in the modus operandi of such operations , but it is not so easy to carry them out practically . Capt. Basevi has undergone a great amount of labour and anxiety , but he has successfully surmuounted all his difficulties . * Instances have occurred in the Lake District of persons who have perished on the hills from prolonged exposure to strong wind and rain , storm-stricken , in the language of the country . t ( ... La cong6lation complete a mime si profondement altere les tissus de l'organisme que quand l'animal est tout a fait degele , son corps est flasque et mou , ses cristallins sont blancs et opaques , et souvent sa coloration est tout a fait alter6e " ( p. 24 ) . He has taken experiments at the following stations , which you will find in the chart at the end of Everest 's description of the measurement of the Indian Arc , Dehra Done , Nojli , Kaliana , Dateri , and Usira . At Debra Done he took six sets of observations with each pendulum ; but finding he could advance more rapidly than the observatories could be got ready for him , at the subsequent stations he took ten sets of observations with each pendulum . Each set was carried over eight to nine hours , from 9 A.M. to 5 ' P.M. The pendulum was set in motion in the morning , the coincidences were observed , and the thermometers and arc of vibration were read hourly , until the set terminated in the afternoon . The first and last coincidences will be used only for determining the number of vibrations ; but the whole of the intermediate temperatures and arcs will be employed for determining the corrections for temperature and arc . He was very fortunate in his transits , only losing four nights in sixty ; complete sets of observations were twice taken at Kaliana ( the northern extremity of the Indian arc ) in December , when the temperature was lowest , and again this month when it was highest ; the range was not so great as we had anticipated , being 58 ? in the first instance , and 92 ? in the second , so that the results will scarcely be applicable to the observations at Kew , where , to the best of my recollection , the temperature was between 40 ? and 50 ? ; but they will amply suffice for all the observations that are likely to be taken in India . He endeavoured to observe at a constant pressure , but the leaking of the cylinder prevented this ; however , the whole range of pressure does not exceed 3 inches , and the average range is much less , the maximum being 5 inches and the minimum 2 . He is about to commence a series of observations at Masoori , at an altitude of about 6800 feet above the sea . He hopes to complete these during June , before the rainy season sets in , when transits will be impossible . During the rains he will be employed in completing the calculations connected with his experiments . By September I hope to be able to send you the final results . He has had so much to do in surmounting the difficulties arising from his new apparatus , that he could not manage to take any magnetic observations . In future , however , he hopes to be able to take these observations regularly at each of his pendulum stations . I trust that you will be gratified with this account of his first year 's operations . No pains have been spared to secure results of the highest possible value , and to reward the confidence you reposed in us , when you suggested to the India Office that we should undertake these delicate and difficult operations . Believe me , yours sincerely , General Sabine , P.R.S. J. WALKER .
112629
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Spectroscopic Observations of the Sun. [Abstract]
256
258
1,866
15
Proceedings of the Royal Society of London
J. Norman Lockyer
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
3
38
1,200
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112629
null
http://www.jstor.org/stable/112629
null
null
Astronomy
32.700857
Atomic Physics
21.570589
Astronomy
[ 14.34463119506836, -33.104331970214844 ]
III . ' Spectroscopic Observations of the Sun . " By J. NORMAN LOCKYER , F.R.A.S. Communicated by Dr. SHARPEY , Sec. R.S. Received October 11 , 1866 . ( Abstract . ) The two most recent theories dealing with the physical constitution of the sun are due to M. Faye and to Messrs. De la Rue , Balfour Stewart , and Loewy . The chief point of difference in these two theories is the explanation given by each of the phenomena of sun-spots . Thus , according to M. Faye - , the interior of the sun is a nebulous gaseous mass of feeble radiating-power , at a temperature of dissociation ; the photosphere is , on the other hand , of a high radiating-power , and at a temperature sufficiently low to permit of chemical action . In a sunspot we see the interior nebulous mass through an opening in the photosphere , caused by an upward current , and the sun-spot is black , by reason of the feeble radiating-power of the nebulous mass . In the theory held by Messrs. De la Rue , Stewart , and Loewyt , the appearances connected with sun-spots are referred to the effects , cooling and absorptive , of an inrush , or descending current , of the sun 's atmosphere , which is known to be colder than the photosphere . In June 1865 I communicated to the Royal Astronomical Society$ * ornptes itenclus , vol. ix . pp. 89-138 , abst , raeted in The Reader , ' 4th February , 1865 . t ' esearches oii Solar Physics . Printed for private circulation . Taylor and Francis , 1865 . t Monthly . Notices . Roy , Ast . 8 , oc ionl xxv . p , 2 37 [ Nov. 15 , 256 some observations ( referred to by the authors last named ) which had led me independently to the same conclusion as the one announced by them . The observations indicated that , instead of a spot being caused by an upward current , it is caused by a downward one , and that the results , or , at all events , the concomitants of the downward current are a dimming and possible vaporization of the cloud-masses carried down . I was led to hold that the current had a downward direction by the fact that one of the cloud-masses observed passed in succession , in the space of about two hours , through the various orders of brightness exhibited by faciulce , general surface , and penembr6e . On March 4th of the present year I commenced a spectroscopic observation of sun-spots , with a view of endeavouring to test the two rival theories , and especially of following up the observations before alluded to . The method I adopted was to apply a direct-vision spectroscope to my 6:-inch equatoreal ( by Messrs. Cooke and Sons ) at some distance outside the eyepiece , with its axis coincident with the axis of the telescope prolonged . In front of the slit of the spectroscope was placed a screen on which the image of the sun was received ; in this screen there was also a fine slit corresponding to that of the spectroscope . By this method it is possible to observe at one time the spectra of the umbra of a spot and of the adjoining photosphere or penumbra ; unfortunately , however , favourable conditions of spot ( i. e. as to size , position on the disk , and absence " of cloudy stratum " ) , atmosphere , and instrument are rarely coincident . The conditions were by no means all I could have desired when my first observations were made ; and , owing to the recent absence of spots , I have had no opportunities of repeating my observations . Hence I should have hesitated still longer to lay them before the Royal Society had not M. Faye again recently called attention to the subject . On turning the telescope and spectrum-apparatus , driven by clock-work , on to the sun at the date mentioned , in such a manner that the centre of the umbra of the small spot then visible fell on the middle of the slit in the screen , which , like the corresponding one in the spectroscope , was longer than the diameter of the umbra , the solar spectrum was observed in the field of view of the spectroscope with its central portion ( corresponding to the diameter of the umbra falling on the slit ) greatly enfeebled in brilliancy . All the absorption-bands , however , visible in the spectrum of the photosphere , above and below , were visible in the spectrum of the spot they , moreover , appeared thicker where they crossed the spot-spectrum . I was unable to detect the slightest indication of any bright bands , although the spectrum was sufficiently feeble , I think , to have rendered thei unmistakeably visible had there been any . Should these observations be confirmed by observations of a larger spot free from " cloudy stratum , " it will follow , not only that the phenomena Y2 presented by a sun-spot are not due to radiation from such a source as that indicated by M. Faye , but that we have in this absorption-hypothesis a complete or partial solution of the problem which has withstood so many attacks . The dispersive power of the spectroscope employed was not sufficient to enable me to determine whether the decreased brilliancy of the spotspectrum was due in any measure to a greater number of bands of absorption , nor could I prove whether the thickness of the bands in the spot-spectrum , as compared with their thickness in the photospherespectrum , was real or apparent only* . On these points , among others , I shall hope , if permitted , to lay the results of future observations before the Royal Society . Seeing that spectrum-analysis has already been applied to the stars with such success , it is not too much to think that an attentive and detailed spectroscopic examination of the sun 's surface may bring us much knowledge bearing on the physical constitution of that luminary . For instance , if the theory of absorption be true , we may suppose that in a deep spot rays might be absorbed which would escape absorption in the higher strata of the atmosphere ; hence also the darkness of a line may depend somewhat on the depth of the absorbing atmosphere . May not also some of the variable lines visible in the solar spectrum be due to absorption in the region of spots ? and may not the spectroscope afford us evidence of the existence of the " red flames " which total eclipses have revealed to us in the sun 's atmosphere ; although they escape all other methods of observation at other times ? and if so , may we not learn something from this of the recent outburst of the star in Corona ?
112630
3701662
On a Crystalline Fatty Acid from Human Urine. [Abstract]
258
259
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15
Proceedings of the Royal Society of London
E. Schunck
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
2
22
571
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112630
null
http://www.jstor.org/stable/112630
null
112,477
Chemistry 2
82.900538
Physiology
8.296562
Chemistry
[ -41.37543487548828, -44.873748779296875 ]
IV . " On a Crystalline Fatty Acid from Human Urine . " By E. SCIUNCK , F.R.S. Received September 21 , 1866 . ( Abstract . ) After referring to the various forms in which fatty matter occurs in human urine , and to our extremely defective knowledge regarding its physical and chemical properties , the author proceeds to describe a process whereby he obtained from healthy urine a small quantity of a substance having the properties characteristic of the fatty acids which are solid at the ordinary temperature . The process consists in passing urine , after having been filtered in order to separate all insoluble matter which may have been deposited , through animal charcoal in an ordinary percolating apparatus . The urine is thereby completely decolorized and deodorized , a small quantity of charcoal producing this effect on a large quantity of urine . The charcoal , after being thoroughly washed with water , is treated with boiling alcohol , to which it communicates a bright yellow colour like * Irradiation would cause bands of the same thickness to appear thinnest in the more brilliant spectrum . 258 [ Nov. 15 , that of urine itself . The filtered alcoholic liquid is evaporated , and the residue is treated with water , which leaves undissolved a quantity of brownish-yellow fatty matter . This , after being purified in the manner described by the author , is found to consist principally of a fatty acid , having the properties characteristic of the group to which palmitic and stearic acid belong . The acid is white , crystalline , has a pearly lustre , melts at 54 ? '3 C. , volatilizes unchanged when heated , and is insoluble in water but easily soluble in alcohol and ether . It is soluble in caustic potash and soda-lye , in aqueous ammonia , and in solutions of carbonate of potash and carbonate of soda . The solutions froth on being boiled like ordinary soap and water . The potash compound is obtained from the watery solution in the form of small pearly scales , and from an alcoholic solution in prismatic crystals . The soda-compound separates from a boiling-hot solution on cooling as a thick , white , amorphous soap , a very small quantity of which is sufficient to cause the liquid to gelatinize . The watery solution of either of these compounds gives white curd-like precipitates with salts of barium , calcium , lead , and silver . The quantity of the acid obtained in the author 's experiments was too inconsiderable to enable him to determine its composition and atomic weight , and it therefore remains uncertain whether it is identical with any of the known fatty acids or not . The author inclines to the opinion that it is a mixture of stearic and palmitic acid , which according to modern investigations constitute together what was formerly called margaric acid . The author does not venture to assert that it forms a normal constituent of the healthy secretion , though the urine employed in his experiments in no case exhibited anything peculiar . The experiments described do not throw any light on the question how this acid , which belongs to a class of substances almost insoluble in water , comes to be dissolved in a liquid like urine , which is itself usually acid .
112631
3701662
On Oxalurate of Ammonia as a Constituent of Human Urine. [Abstract]
259
260
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Proceedings of the Royal Society of London
E. Schunck
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
2
16
416
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112631
null
http://www.jstor.org/stable/112631
null
112,478
Chemistry 2
94.211406
Biology 2
3.97765
Chemistry
[ -40.90018844604492, -45.61112976074219 ]
V. On Oxalurate of Ammonia as a Constituent of Human Urine . " By I. SCHUNCK , F.R.S. Received November 15 , 1866 . ( Abstract . ) When ordinary healthy urine is passed through animal charcoal in the manner described in the preceding paper , several organic substances are separated and absorbed by the charcoal in addition to the fatty acid there referred to . The liquid obtained by treating the charcoal with boiling alcohol having been evaporated , the residue is treated with water , which leaves the fatty acid undissolved . The filtered liquid yields on evaporation a quantity of crystals , which , after being purified in the manner described by the author , are found to have the properties and composition of oxalurate of ammonia . The watery solution of the substance gives with acids a white crystalline precipitate of oxaluric acid ; with nitrate of silver it produces a precipitate which dissolves without change in boiling water , the solution on cooling depositing white silky needles of oxalurate of silver . The lead compound produced by adding acetate of lead to the watery solution , forms well-defined prismatic crystals . With chloride of calcium the watery solution gives no precipitate , but on adding ammonia and boiling , there is an abundant precipitation of oxalate of lime . By treatment with strong acids the substance is decomposed , yielding oxalic acid and urea . Its composition was found to correspond with the formula C 1-1 N3 0O , which is that of oxalurate of ammonia . The author 's experiments were not sufficiently numerous to decide the question whether this salt is . a normal constituent of human urine or not . There is no doubt , however , that its presence , whether exceptional or not , affords an easy and satisfactory explanation of a phenomenon which has until now proved very puzzling , viz. , the formation of oxalate of lime in urine long after its emission . It is doubtless owing to the decomposition of oxaluric acid , which takes up water and splits up into urea and oxalic acid ; the latter then combines with lime , of which there is always a sufficient quantity present to saturate the acid . There can be little doubt also that oxaluric acid is derived in the animal frame , as in the laboratory , from uric acid , the oxidation of which is its only known source .
112632
3701662
On the Structure of the Optic Lobes of the Cuttle-Fish. [Abstract]
260
261
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Proceedings of the Royal Society of London
J. Lockhart Clarke
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
2
31
786
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112632
null
http://www.jstor.org/stable/112632
null
108,973
Neurology
76.782529
Biology 3
16.353014
Neurology
[ -80.72510528564453, 10.23890209197998 ]
VI . " On the Structure of the Optic Lobes of the Cuttle-Fish . " By J. LOCKHIART CLARKE , F.I.S8 . Received September 26 , 1866 . ( Abstract . ) The brain of the Cuttle-fish consists of several ganglia closely aggregated around the upper part of the oesophagus . The foremost or pharyngeal ganglion , which is much the smallest , is bilobed and somewhat quadrangular . The next is a large bilobed ganglion which forms the roof of the canal for the oesophagus . Beneath the oesophagus is another large and broad mass , which is connected on each side with the supra-cesopbageal masses by bands that complete the oesophageal ring . From each side of the cephalic masses springs a thick optic peduncle which ends in the optic lobe . Each optic lobe is larger than all the other cerebral masses taken together , and has a striking resemblance in shape to the human kidney . It is completely enveloped in a thick layer of optic nerves disposed in flattened bands which issue from all parts of its substance and proceed to the back of the eye in a fan-like expansion , the upper and lower bands crossing each other in their course . The substance of each lobe consists of two distinct portions , which differ from each other entirely in appearance . The outer portion resembles a very thin rind or shell , is extremely delicate , and very easily torn from the central substance which it encloses . It consists of three concentric layers-an external dark layer , an internal dark layer , and a middle pale and broader layer containing thin and concentric bands of fibres . The first or outer layer consists of a nultitude of nuclei and a fw small nucleated cells , with which filaments of the optic nerves-are connected . The second or middle layer is composed entirely of fine nerve-fibres which form two sets-one vertical , and the other horizontal . The vertical fibres issue at the under surface of the first layer from the network which its nuclei form with the fibres of the optic nerves . Some are continuous with the horizontal fibres , but the majority continue downward across them to the third or inner layer . At the junction of these two layers is a row of nucleated cells which send thin processes in different directions , and with which some of the nerve-fibres are connected . The third or inner layer is composed entirely of closely-aggregated nuclei , which are joined together in a network by the fibres which issue from the unlder surface of the middle layer . The cortical substance , consisting of these three layers , forms only a very small portion of the optic lobe . Out of the nulecar network of the inner layer fine nerve-fibres descend into the body of the lobe which it encloses . At first these fibres are vertical , parallel , and arranged in uniform series , with scattered nuclei between the m ; but as they descend to the centre of the lobe , they diverge more and more , and cross each other to form a plexus , first with oval and then with broader meshes , in which the nuclei and nucleated cells are collected into groups of corresponding shape and size . From the plexus at the inner side of the lobe bundles converge from all parts to form the lower half of the peduncle , the upper part of which consists of masses of small nuiclei , and gives attachment , by a short pedicle , to a small tubercle . This tubercle consists of closely-aggregated nuclei connected by fibres which converge to its neck and escape into the peduncle of the optic lobe . After concluding his description of the optic lobes , the author gives a short account of the structure and connexions of the remaining cerebral ganglia of the Cuttle-fish , with the view of determining their homologies . From the nature of the parts which it supplies , the foremost or pharyngeal ganglion weould seem to combine the function of the centres which give origin to the trigeminal , the olfctory , and the gustatory nerves in the vertebrata . The second bi ! obeed ganglion appears to correspond partly to the cerebral lobes and partly to the cerebellum of fshes . The posterior portion of the submcsophageal mass is the analogue of the medulla oblongata ; while the anterior portion may be regarded as the spinal cord concentrated below the csophagus and in the neighbourhood of the feet , which derive all their nerves from that source .
112633
3701662
On the Laws of Connexion between the Conditions of a Chemical Change and Its Amount. No. II. On the Reaction of Hydric Peroxide and Hydric Iodide. [Abstract]
262
265
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Proceedings of the Royal Society of London
A. Vernon Harcourt|W. Esson
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
4
57
1,923
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112633
null
http://www.jstor.org/stable/112633
null
null
Chemistry 2
43.183001
Thermodynamics
17.901678
Chemistry
[ -27.029375076293945, -59.63074493408203 ]
I. " On the Laws of Connexion between the conditions of a Chemical Change and its Amount . " No. II . " On the Reaction of Hydric Peroxide and Hydric lodide . " By A. VERNON IlARcoUuT , M.A. , and W. ESSON , M.A. Communicated by Sir BENJAMIN COLLINS BRODIE , Bart. Received July 13 , 1866 . ( Abstract . ) In a former paper , of which an abstract appeared in the Royal Society 's Proceedings , vol. xiv . p. 470 , the authors gave an account of their first experiments on this subject . The second chemical change chosen for investigation was that which occurs in a solution containing hydric iodide ( hydriodic acid ) and hvdric peroxide . In this case the amount of change stands in relation to the following conditions , -(l ) the nature of the solution , that is to say , its temperature , and the nature and quantity of the different ingredients which it contains in a unit of volume , ( 2 ) the quantity of the solution , or the number of such iunits of volume , ( 3 ) the time during which the change proceeds . The relation of the amount of change to the second and third of these conditions is determinate : it varies directly with each ; for the solution is homogeneous , and , if all other conditions are fixed , the rate of change is uniform . But the first condition comprises an almost indefinite number of particular conditions ; for not only may various iodides and per oxides be used without , as far as we know , altering the nature of the reaction , but other substances may be introduced into the solution , and their influence upon the amount of change determined . The present paper contains an account of the methods employed for observing this reaction , and of the results obtained by varying two particular conditions , namely the amounts of peroxide and of iodide . If hydric peroxide and hydric iodide , or barytic peroxide , potassic iodide , and hydric chloride , be brought together in dilute solution at the ordinary temperature , a gradual development of iodine takes place . If a drop of a dilute solution of sodic hyposulphite be added to the mixture capable of reducing to iodide all the iodine which has been formed up to the time of its addition , but not all that will be formed in the course of the reaction , the liquid which had become yellow becomes colourless , remains colourless for a while , and then suddenly becomes yellow again . This yellow colour may be exchanged for a more intense blue colour by putting starch into the solution . It was found that in dilute solutions no direct oxidation of hyposulphite by peroxide took place ; and that the quantity of hyposulphite required to reduce the iodine liberated by a measure of peroxide was the same , whether the hyposulphite were added little by little during the course of the reaction , or after the primary reaction had completed itself , and when no peroxide remained in the solution . The method of observation founded upon these facts was briefly as follows : Measured quantities of all the standard solutions , except that of hydric peroxide , were introduced into a glass cylinder about 11 inches high by 3 broad , and water was added till the upper surface of the liquid was level with a line drawn round the cylinder . This adjustment of volume was made through a hole in the bung , which closed the cylinder ; two other holes admitted a thermometer and an inverted funnel-tube . A current of carbonic acid passing down the funnel-tube to the bottom of the cylinder , and rising in large bubbles from the mouth of the funnel , served at once to stir the liquid constantly , and to protect its upper surface from the air . When the volume and the temperature of the solution had been adjusted , a small measure of hyposulphite was first added , and then the pipetteful ( 10 cub. centims. ) of peroxide . The cylinder was placed on a sheet of white paper in front of a clock beating seconds . By watching the surface of the fluid and counting the seconds when the time of an observation was near , it was possible to note accurately the moment at which the colour changed . A second small measure of hyposulphite was then introduced , and at the proper interval a second observation was made . Each such addition of hyposulphite , with the observation preceding and following it , is spoken of as an experiment , and these experiments were continued until the reducing power of the last measure of hyposulphite being greater than the oxidizing power of the remaining peroxide the blue colour did not return . The small measures of hyposulphite consisted of single drops collected under circumstances favourable to their perfect uniformity . The peroxide employed was either an acidified solution of sodic peroxide , or dilute hydric peroxide obtained by the distillation of such a solution . In each set of experiments the value of the measures of hyposulphite and of the pipetteful of peroxide could be compared by determining what fraction of a measure of hyposulphite remained in the solution when the set of experiments had been brought to an end . These values could also be compared by determining each with a standard solution of potassic permanganate . In presence of an excess of potassic iodide , sodic hyposulphite may be estimated by this reagent exactly as it may by standard iodine solution . During each set of experiments , then , all the conditions of the reaction are constant except two , which are progressively modified . One of these is immaterial , the accumulation of a small quanitity of sodic tetrathionate ; the other is material , the gradual disappearance of the small quantity of peroxide upon whose presence the reaction depends . The first point , therefore , requiring to be investigated was the law of connexion between the amount of change and the amnount of peroxide . Since the amount of peroxide originally taken is known , and also the amount which corresponds to a measure of hyposulphite , the amount remaining in the solution at the moment of each observation is also known . Thus the data supplied by each experiment are ( 1 ) the amount of peroxide present in the solution at a particular moment of time , ( 2 ) the time at which this amount is present , ( 3 ) the amount present at a subsequent moment of time , ( 4 ) the time at which this amount is present . Representing these two amounts of peroxide by y and y1 respectively , and the corresponding moments of time by t and t ' , the result of each experiment is that an amount of chemical change y-y ' has been accomplished in an interval tt-t . According to the hypothesis proposed in our former paper , namely that the amount of chemical change varies directly with that of each of the substances partaking in it , these quantities should exhibit throughout a set of experiments the constant relation y_eQ(t'-t ) The numerical results obtained in various sets of experiments performed under different circumstances are compared with those calculated from equations of this form , and the two are shown to agree within narrow limits of experimental error . It is inferred that in this case the amount of chemical change taking place at any moment is proportional to the amount of peroxide present at that moment in the solution . The constant a in the preceding equation represents the effect upon the amount of change of those conditions which do not vary in a set of experiments ; and it is possible by varying one of these conditions in different sets of experiments , and determining the value of a in each , to inquire into the law of connexion between the condition thus varied and the amount of change . Accordingly a series of sets of experiments was made , in which , all else being kept constant , different quantities of potassic iodide were used in different sets . It is shown that the values of a derived from the different sets of experiments are proportional to the quantities of iodide used in each case . In this series hydric sulphate was an ingredient of the solutions ; a second series was made , in which an equivalent quantity of hydric chloride was substituted . The result , as regards the effect of varying the amount of iodide , was the same as in the previous series . The rate of chemical change , that is to say the amount in a given time with a constant quantity of peroxide , was found to be directly proportional to the amount of iodide in the solution . Thus the law of connexion is the same in this case as in that already investigated of the variation of peroxide . The total amount of chemical change is a function of all the conditions of the system in which it occurs . If we call this amnount X , the volume of the solution v , its temperature t , the time during which the change proceeds t , and the amounts of the various ingredients , peroxide , iodide , &c. in a unit of volume , p , i , a , b , c. . , then f(a , b , c,. . A ... , ... t. . v ... ) . The form of this function is determinate in the case of two of these conditions , viz. v , t , and has now been determined experimentally in the case of p and i , so that the equation may be written in the form E:=i-p t v. f ( a , c ... . . ) . The number of ingredients , represented by a , 6 , c , &c. , which may be introduced into the system and affect the amount only , and not the nature of the chemical change , and which may therefore be regarded as so many conditions of the reaction , is doubtless very large . The authors believe that the investigation of the influence of some of these may prove of interest , it being possible thus to compare various substances which may be substituted one for another in the system by a new standard . They find , for example , that comparing equivalent quantities ( in the ordinary chemical sense ) of hydric sulphate and hydric chloride , the effect of the latter is nearly double that of the former . But the most important condition of the change whose influence is still undetermined is that of temperature , for this condition intervenes under all circumstances of the reaction , and indeed in all chemical changes whatever . The authors have already made many experiments on both these points . The results of this investigation , which will complete the study of the reaction , may , they hope , formf the subject of a subsequent communication .
112634
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On the Stability of Domes.--Part II. [Abstract]
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E. Wyndham Tarn
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61
1,200
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Measurement
46.247036
Fluid Dynamics
24.336903
Measurement
[ 57.856868743896484, -23.544559478759766 ]
II . " On the Stability of Domes."-Part II . By E. WYNDHAM TARN , M.A. , Memb. Roy . Inst. Brit. Architects . Communicated by G. GODWIN , Esq. Received October 23 , 1866 . ( Abstract . ) In a former paper on this subject which the author presented to the Royal Society , and which is published in the 'Proceedings ' ( vol. xv . p. 182 ) , he obtained formulae for calculating the thrust of a spherical dome of uniform thickness , by supposing it to consist of a number of thin ribs , each of which is formed by two vertical planes intersecting at the axis of the dome , and making a small angle with each other ; and then treating each rib as forming , with the corresponding one of the opposite side , a complete arch . In the present paper the author applies the same method to domes of other forms than the spherical . The following are the kinds for which the formulm are investigated : A. The Gothic dome , of which that of the cathedral at Florence is a splendid example . This kind has for its section a pointed arch formed by two segments of circles , the centre from which each is struck being on the springing line , but not in the axis of the dome . The author denotes by a the angle between the vertical and a line drawn from this centre to the point , near the crown of the dome , where its axis is intersected by a circle drawn around that centre with a radius equal to the mean of the radii of the circles which generate the outer and inner surfaces of the dome , and reduces his results to numbers for three different values of the angle a. B. A dome whose inner surface is a paraboloid of revolution , the thickness of the shell being uniform throughout . C. The dome whose surface is formed by the revolution of an ellipse about its major axis . In the investigation , the two surfaces are supposed to be generated by the revolution of two concentric elliptic quadrants , whose major axes differ from one another by the same quantity as the minor axes , so that the thickness is very nearly uniform throughout . D. A form of dome commonly used in eastern countries , sometimes called the ogival dome , the surface of which is generated by the revolution of a curve which has a point of contrary flexure . In the investigation , the author takes for this curve the curve of sines , the equation of which is y'=r sin- , where x ' , y ' are the vertical and horizontal coordir nates of a point in the generating curve , and supposes the outer and inner surfaces to be generated by the revolution of two such curves , differing only by the value of r , the origin being the same . The following Table exhibits the principal results obtained from the author 's investigations . All the domes , except the last , are supposed to be of the uniform thickness throughout of 1 foot . In the last the thickness is 1 foot at the springing , but gets rather less towards the top . The domes are supposed to be built of material weighing 125 lbs. to the cubic foot . The thrust is calculated for the 180th part of the whole dome , being the portion cut out by two planes which make an angle of 2 ? at the axis . Table showing the position of the weakest joint in domes of various forms , and the horizontal thrust at that joint . Greatest horiPosition of the weakest ; ltt h Form of Dome . Span . joint , or joint where oal thrust a or thrust at thrust is greatest . est j weakest joint . lbs. 1 . Hemisc~ fact . ~ Malakes with springing line 201 1 . H emisphere ... ... ... ... . . 2a ... . i{ angl of 20 9201 Hemispe1 r 20 an angle of 20 ? . f 2 . Gothic , a -10 ... ... . . Makes with springing line 88'7 a20 l an angle of 17 ? . 3 . gothic , a{22-2 0 . 20 { } Makes with springing lineil 3 . Gothic , a=22- ... ... ... ... .{^anSTo ? r^^^^^ 80 ? 418 4 . Gothic , a=30 ... ... ... ... ... { 77-27 4 . GoiC , a-o *--30 0.@@@ 20 l Makes with springing line }727 5 . Parabolic ; height above springing equals th half 2 At springing line 79-6 span . 6 . Elliptical , major axis verOne-third of semimajor tical ; ratio of major to 0 axis above springing 90-867 minor axis as 6 : 5 . 1 line . 7 . Ogival ; contour , the " curve J One-sixteenth of the span l 625 of sines . " 20 above springing line . I In the preceding cases , except the last , the domes are assumed to be of uniform thickness . The author finally applies his formulae to the case of the spherical dome in which the thickness at the crown is one-half that at the springing , the inner surface being generated by the revolution of a circular quadrant whose centre is raised above the centre of that which generates the outer surface by half the difference of the radii . Assuming the outer and inner radii R , r to be respectively 11 feet and 10 feet , he finds that the weakest point on a dome of this form appears to be at a height equal to LR above the springing line ; and with the other numerical values , assumed the same as before , he finds for the horizontal thrust at the weakest joint 55178 lbs. For each kind of dome the author forms what he calls the equation of stability , giving , for an assumed value of the height of the pier , the least thickness t which will permit of stability . The following are the results for each kind of dome , the height of the pier being taken at 50 feet : Spherical dome ( from former paper ) ... t=2'45 feet . Gothic dome ( a==22 ) ... ... . t=2-259 , Parabaloidal domee ... ... . t-=2244 , , Elliptic dome ... ... ... . . t244 , , Ogival dome ... ... ... 2 , , Spherical dome ( thinner at crown ) ... . t= 1'9 The author considers what he has found as the weakest part of a dome to be the position in which an iron belt must be placed to produce the greatest effect in counteracting the thrust of the dome . If this be done , the thickness of the pier may be considerably diminished , and need not greatly exceed the strength necessary for supporting the superincumbent weight acting vertically downwards .
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A Supplementary Memoir on Caustics. [Abstract]
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Proceedings of the Royal Society of London
A. Cayley
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Formulae
63.839288
Optics
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Mathematics
[ 64.96564483642578, -27.52897071838379 ]
III . " A Supplementary Memoir on Caustics . " By A. CAYLEY , F.R.S. Received November 15 , 1866 . ( Abstract . ) It is near the conclusion of my " Memoir on Caustics , " Phil. Trans. vol. cxlvii . ( 1857 ) , pp. 273 , 312 , remarked that for the case of parallel rays refracted at a circle , the ordinary construction for the secondary caustic cannot be made use of ( the entire curve would in fact pass off to an infinite distance ) , and that the simplest course is to measure off the distance GQ from a line through the centre of the refracting circle perpendicular to the direction of the incident rays . The particular secondary caustic , or orthogonal trajectory of the refracted rays , obtained on the above supposition was shown to be a curve of the order 8 ; and it was further shown by consideration of the case ( wherein the distance GQ is measured off from an arbitrary line perpendicular to the incident rays ) , that the general secondary caustic or orthogonal trajectory of the refracted rays was a curve of the same order 8 . The last-mentioned curve in the case of reflexion , or for t , =-1 , degenerates into a curve of the order 6 ; and I propose in the present supplementary memoir to discuss this sextic curve ; viz. the sextic curve which is the general secondary caustic or orthogonal trajectory of parallel rays reflected at a circle .
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Biography
61.69668
Optics
8.271295
Biography
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III . " A Supplementary Memoir on Caustics . " By A. CAYLEY , F.R.S. Received November 15 , 1866 . ( Abstract . ) It is near the conclusion of my " Memoir on Caustics , " Phil. Trans. vol. cxlvii . ( 1857 ) , pp. 273 , 312 , remarked that for the case of parallel rays refracted at a circle , the ordinary construction for the secondary caustic cannot be made use of ( the entire curve would in fact pass off to an infinite distance ) , and that the simplest course is to measure off the distance GQ from a line through the centre of the refracting circle perpendicular to the direction of the incident rays . The particular secondary caustic , or orthogonal trajectory of the refracted rays , obtained on the above supposition was shown to be a curve of the order 8 ; and it was further shown by consideration of the case ( wherein the distance GQ is measured off from an arbitrary line perpendicular to the incident rays ) , that the general secondary caustic or orthogonal trajectory of the refracted rays was a curve of the same order 8 . The last-mentioned curve in the case of reflexion , or for t , =-1 , degenerates into a curve of the order 6 ; and I propose in the present supplementary memoir to discuss this sextic curve ; viz. the sextic curve which is the general secondary caustic or orthogonal trajectory of parallel rays reflected at a circle . November 30 , 1866 . ANNIVERSARY MEETING . Lieut.-General SABINE , President , in the Chair . Dr. Gladstone , on the part of the Auditors of the Treasurer 's Accounits appointed by the Society , reported that the total receipts during the past year , including a balance of ? 15 9s . carried from the preceding year , amounted to '4295 16s . lid . ; and that the total expenditure in the same period amounted to ? 3629 15s . 5d . , leaving a balance of ? 638 8s . ld . at the Bankers , and of X27 13s . 5d . in the hands of the Treasurer . The thanks of the Society were voted to the Treasurer and Auditors . The Secretary read the following Lists Fellows deceased since the last Anniversary . Royal . His Majesty Leopold , King of the Belgians , K.G. On the -Home List . Benjamin Guy Babington , M.D. William Thomas Brand , D.C.L. Right Hon. Sir James Lewis Knight Bruce , Knt. , D.C.L. Richard John Hely H-utchinson , Earl of Donoughmore . Sir Charles Locke Eastlake , D.C.L. Joseph Edye , Esq. G. W. Featherstonhaugh , Esq. Charles Lord Glenelg , D.C.L. William Gravatt , Esq. John Scandret HIarford , D.C.L. Charles James I-argreave , LL. D. William Henry Harvey , M.D. Robert H-unter , Esq. Percival Norton Johnson , Esq. Edward Kater , Esq. John Lee , LL. D. Rev. Samuel Roffy Maitland , D.D. Thomas Spring Rice , Lord Monteagle of Brandon . Francis Thornhill Baring , Baron Northbrook . I-oratio William Walpole , Earl of Orford ( in 1858 ) . George Rennie , Esq. HI-enry Darwin Rogers , LL. D. Edward James Seymour , M.D. Samuel Reynolds Solly , Esq. Joseph Toynbee , Esq. Lieut.-Col. Sir John Maxwell Tylden , Knt. Rev. William Whewell , D.D. Right Hon. Sir James Wigram , Knt. , M..A . Nicholas Wood , Esq. On the Foreign List . Georg Friedrich Bernhard Riemann . OChange of NVamne . Rev. IHenry Christmas to Noel-Fearn , Defaulter . Colonel John Le Couteur . Fellows elected since the last Anniversary . On the Home List . John Charles Bucknill , M.D. The Ven . John Henry Pratt , f.A. Rev. Frederic William Farrar . Capt. George Henry Richards , R.N. William Augustus Guy , M.B. Thomas Richardson , Esq. , M.A. James Hector , M.D. WVilliam Henry Leighton Russell , John William Kaye , Esq. Esq. Hugo Miiller , Ph. D. Rev. William Selwyn , D.D. Charles Murchison , MII . D. Rev. Richard Townsend , M.A. William Henry Perkin , Esq. Henry Watts , B.A. On the Foreign List . Franz Cornelius DondCers . Gustav Rose . Georg Friedrich Bernhard Riemann . Reacdmitted . William Bird HI-erapath , M.D , The President then addressed the Society as follows : GENTLEMEN , DURING the autumnal recess , and in the absence of the President , the Treasurer , on learning that the Government had it in contemplation to assign the main building of Burlington House , now appropriated to the Royal , Chemical , and Linnean Societies , to the Royal Academy ( together with ground in its rear for the erection of additional buildings ) , deemed it advisable in the interests of the Society , and after consultation with the Senior Secretary , to address a letter to the Earl of Derby . The officers of the Society were referred by his Lordship to the Chief Commissioner of Works , by whom they were informed in reply that due provision was to be made for the Societies , and that the Architects , Messrs. Banks and Barry , with whonr the Office were to advise on the subject , were instructed to confer with the Council of the Royal Society . Those gentlemen having accordingly communicated to the Council that they are directed to report to the Government on the accommodation that can be provided for the Royal and the other Societies in new buildings , to occupy part of the space between Burlington House and Piccadilly , the Council have appointed a Committee to consider the whole matter and to confer with the Architects thereupon . The Committee have had an interview with Mr. Banks , and have handed in a statement setting forth the nature and extent of accommodation that will be required for the Society in lieu of their present apartments . There , so far as we are informed , the matter rests for the present , but from the tenor of the communications which have passed , there seems every reason to feel confident that the Society will be suitably and amply provided for . I had the pleasure of announcing at the last Anniversary that the printing of the Catalogue of Scientific Papers , in the preparation of which we have been so long engaged , was at length commenced . Twentyeight quarto sheets are now printed and eight more are in type . The work would now have been further advanced , had not the Superintending Commitee in the mean time obtained access to additional Periodical Works , containing TMemoirs deserving , to be included in the Catalogue , and too numerous to warrant their being postponed for a supplement . The printing has therefore been interrupted for a time in order to allow of the insertion of these additional titles in their proper places . Moreover , proofs of every sheet are supplied to several of the Members of the Library Committee who separately revise them ; and this mode of proceeding no doubt somewhat protracts the work , but it has the more than compensating advantage of securing the greatest attainable accuracy . The attention of your Council has been much occupied in the past year in complying with a request from Her Majesty 's Government for the advice and co-operation of the Royal Society in the re-organization of the Meteorological Department of the Board of Trade , and in preparing the preliminary arrangements for the establishment of a system of British LandMIeteorology to be carrieed out under the authorization of that Board . Perhaps there is no branch of scientific research in which a greater amount of human labour has been expended than has been the case in Meteorology , -a natural consequence of its intimate connexion in so many ways with the interests and pursuits of man ; and it may perhaps be said with equal truth that there is no department of natural knowledge in which the labour bestowed has beein of a more desultory character , or the value and importance of the conclusions less commensurate with the time and labour bestowed on their acquisition . The object to be desired , therefore , is scarcely so much to give a stronger impulse to the spirit of inquiry , as to aid in giving to that which exists a more systematic direction . This has been attempted in several of the continental States of Europe and America , by the establishment at the expense of the respective governments , and under the superintendence of men eminently qualified by theoretical and practical knowledge , of systematic climatological researches ; and , as regards the individual states themselves , it may be confidently said that the results have been very beneficial . For some time past it lias been desired to establish a closer connexion between these independent and separate systems of observation , by effecting an assimilation of instrumental means , and of the modes and times of observation . It was chiefly in this view that the assemblage took place by special invitation , at the Cambridge Meeting of the British Association in 18-15 , of the Directors of the principal meteorological ( and magnetical ) observatories in Europe and America ; and that a second meeting took place at Brussels in 1853 . The difficulty that impeded success on these two occasions cannot be better stated than in the words of Captain ; faury , in his Report to the Government of the United States , by whom he had been appointed to visit the principal European Meteorological Observatories for the express purpose of urging a uniformity of procedure . " I would recommend that the United States should abandon , for the time at least , that part of the ' Universal System ' which relates to the Land , and that we should direct our efforts mainly to the Sea , where there is such a rich harvest to be gathered for navigation and commerce . I am inclined to make this recommendation in consequence of the evident reluctance with which Russia , Austria , Bavaria , Belgium , and other powers seem to regard any change in their systems of meteorological observations on shore . Each country seems to have adopted a system of its own , according to which its labourers have been accustomed to work , and to which its meteorologists are more or less partial . Any proposition having in view for these systems a change so radical as to bring them into uniformity , and reduce them to one for all the world would , I have reason to believe , be regarded with more or less jealousy by many , -not so , however , with regard to the sea ; that proposal meets with decided favour and warm support . " The most hopeful way of removing the difficulties which impeded the adoption of a system in which all might willingly unite was obviously the introduction of instruments which should be continuously self-recording , and which , after sufficient trial , should receive general approval . The importance of such a substitution had been recognized at the Observatory of the British Association at Kew at a very early date , even before the Cambridge Meeting of the British Association in 1845 ; and at that meeting the satisfactory performance was announced of a photometrically selfrecording barometer , self-compensated also for temperature , devised by Mr. Francis Ronalds , the Honorary Director of the Kew Observatory , the same to whose merits in regard to the instantaneous transmission of messages by means of electricity , at the very early date of 1823 , attention has been recently called in the public journals . Encouraged by this success in one instrument , the Directors of the Kew Observatory proceeded , as rapidly as the means at their disposal enabled them to do , towards the provision of self-recording instruments for the other meteorological elements ( as well as for the magnetical elements ) , and were considerably advanced in their preparations when in 1854 the Board of Trade informed the President and Council that , in fulfilment of a previous earnest recommendation to that effect from the Royal Society , they were " s about to submit to Parliament an estimate for an office for the discussion of observations on meteorology made at sea in all parts of the globe ; " adding that , ( " as it may possibly happen that observations on Land upon an extensive scale may hereafter be made and discussed in the same office , it is desirable that the Royal Society should keep in view and provide for such a contingency . " The subject of a Government system of 1Meteorological Observations on Land was again brought under the consideration of the Royal Society in a letter from the Board of Trade in N:ay 1865 , and the President and Council were expressly requested to offer suggestions in reference to it . The suggestions which they offered in reply have been made known to the Society , in their leading outlines at least , in my Address of last year , and in No. 82 of our ' Proceedings . ' They have been submitted by the Board of Trade to a Committee appointed by itself , whose general approval they are understood to have received ; and the whole scheme is now under the consideration of Government in respect to its cost . The sea-observations , so hopefully spoken of by Captain Maury , were the subject of a very full communication addressed by the President and Council of the Royal Society to the Board of Trade in February 1855 , and the recommendations contained therein were made the basis of the instructions given to the Meteorological Office of the Board of Trade at its first formation . The collection of what have since been comprehended under the general designation of " Ocean Statistics " proceeded for some time with much activity and success under the direction of our lamented Fellow the late Admiral FitzRoy . His exertions and those of his assistants were afterwards in great measure diverted to an object which , if it could be-or , to speak more sanguinely , whenever it shall become-practically attainable with a fair measure of scientific certainty , will assuredly both deserve and receive in the highest degree general favour and support . I mean the system popularly known by the appellation of " storm-warnings . " Meanwhile , if the recommendations of the Royal Society and the intentions entertained by the Board of Trade shall now receive the hoped-for sanction of the general government , the collection of ocean statistics and their systematic combination will be resumed with fresh vigour , and with all the aids which experience and matured scientific consideration can afford ; and at the same time , if our hopes respecting the proposed system of Land-Meteorology are realized , and if its fruits correspond in a fair degree to the expectations which we venture to form respecting them , we shall gradually obtain such a more complete knowledge of the laws which govern the changes of weather in the British Islands and their vicinity , as may enable the predictions of approaching storms or " storm-warnings , " if now suspended , to be resumed hereafter , and at no very distant period , with far greater confidence and more assured advantage . At our last Anniversary I acquainted you that the Legislature of Victoria hadvoted the sum of 5000 for the construction of a large reflecting telescope to be erected at Melbourne and employed in a thorough survey of the Nebulsm and multiple stars of the southern hemisphere . They also requested the cooperation of the President and Council of the Royal Society in arranging a contract for the work and superintending its execution . We selected for the task one of our Fellows , Mr. Grubb of Dublin , whose well-known optical and mechanical talents gave sure promise of success , and we obtained for him the advantage and assistance of a Superintending Committee , consisting of our late President the Earl of Rosse , Dr. obinson , and Mr. Warren z De la Rue . The contract for the work was signed on the 19th of January ; the progress has been rapid , and I have great pleasure in informing you that , according to all appearance , the instrument will be ready for trial in the spring of 1867 . All the large parts of it are ready for mounting , and the rest considerably advanced . The lattice-tube , the appearance of which is known to many of us from the photographs , is put together . It is made of ribs of steel to combine lightness and strength ; they are rolled taper to effect this in the highest degree . The equilibrated systems of levers which support the great speculum , with their boxes , are of the same material and are also completed . Three specula have been cast on a plan differing from that of Lord Rosse only by such modifications as were made necessary by their having central apertures . The first speculum came out sound from the annealing furnace , but had two blemishes on its surface which would have required a month to grind out , and Mr. Grubb broke it up without hesitation , though not many years ago such a disk would have been almost inestimable . The second cast has been successfully ground , and its surface is faultless . The third , a duplicate speculum , was cast on the 24th of October . The grinding has been performed by the polishing machine and steam-engine which belong to the telescope , and will accompany it to Melbourne . The trial-piers on which the instrument is to be set up for the examination of the Superintending Committee , are ready . At the request of the Board of Visitors of the iMelbourne Observatory , and at the recommendation of the aforenamed Superintending Committee , I have appointed as Observer with this telescope IMr . Albert Le Sueur , a Graduate at Cambridge and a Wrangler in 1863 . Ie is at present training himself in sidereal astronomy at the Cambridge Observatory under the guidance of Professor Adams , and will be present at the polishing of the specula . ir . De la Rue has kindly promised to instruct him in the practice of celestial photography ; so that there is reason to hope that this magnificent instrument will be used with full intelligence and zeal , and amply repay the munificent spirit that has guided the Legislature of this energetic and prosperous colony . The large appropriation made by the Colony of Victoria for the construction of this telescope and for its accompanying spectroscope , and for a suitable provision for its effective employment at Melbourne , have not been the only manifestation in the present year of the enlightened spirit which animates and guides the Legislature of that colony . A sum has been remitted and received in this country for the purchase of a complete equipment of self-recording magnetical instruments on the model of those at the Kew Observatory , to be located in the Government Reserve adjacent to the Melbourne Astronomical Observatory , and to be empioyed under the superintendence of its director , Mr. Ellery . The instruments have been made and verified under the immediate care of the Director of the Kew Observatory , and have been despatched to their destination . system of intended observation is modelled on that exemplified at the Kew Observatory . The intention , adverted to in my last year 's Address , of the Government of Miauritius to establish there a magnetic observatory , working with the instruments and adopting the methods exemplified at Kew , has been since matured . The necessary funds have been remitted , and the instruments are made and are now under process of verification , at Kew , where Professor Mfeldrum , the Director of the Mauritius Observatory , is daily expected to arrive , with the view of making himself thoroughly acquainted with the instruments , and with the processes in which they are to be employed . The geographical position of iMauritius is a very important one , both for magnetical and meteorological observations . Hitherto meteorology has been exclusively pursued there , and the researches of Professor lCeldrun on the cyclonic storms which prevail in the vicinity of the Island are well known . Those of our Fellows who remember the assiduity and devotion to scientific pursuits manifested by Mr. Charles Chambers during his employment as one of the assistants of the Kew Observatory , will be glad to learn that he has received from the Government of Bombay the temporary appointment of Superintendent of the Bombay Magnetical and Meteorological Observatory , and in that capacity has been required to submit a scheme for the reorganization of the observatory , with instruments and methods of research suitable to the advance which has been made in these respects in the last twenty-five years . 3r . Chambers 's report is understood to be on its way from the Government of Bombay to the India Office , with a view to its being submitted to the consideration of the President and Council of the Royal Society ; and should it be approved , it will probably lead to the permanent employment of 3Mr . Chambers in his present temporary position , and to the thorough utilization of the observations of past years , in addition to the prospect of most efficient work at this observatory , under the best conditions , both personal and material , for the future . I have to add to the list of magnetic observatories established in the present year one at the Roman Catholic College at Stonyhurst , supplied with the Kew instruments , and pursuing the same methods of observation and reduction . I refer to this with the greater satisfaction , because in addition to the value to science of the actual work performed at the observatory , it may be expected to be , and is expressly designed by the authorities of the College to be a means , amongst others adopted by them , of fostering among the students a taste for scientific pursuits , which may remain with them in after life . For this latter purpose Stonyhurst has added to the more ordinary modes of instruction in natural knowledge that practical instruction which is only to be gained by working under proper tuition in observatories and laboratories directed to special scientific pursuits , among which magnetism , terrestrial and celestial , may now be considered to have taken its place . It was from the twofold motive of aiding the advancement of science by this additional observatory on the one hand , and on the other of contributing to the dissemination of a taste for scientific pursuits among a large class of our gentry , that the Council of the Royal Society thought it right to allot last year from , the parliamentary grant annually placed at their disposal , a sum sufficient to defray half the cost of a set of magnetical iun struments for Stonyhurst . This is the fortieth year since Mr. Schwabe began at Dessan his series of observations on the Solar spots , which he has continued without intermission from 1826 to the present time . Impressed with the extreme desirableness of continuing beyond the limits of a single life a series already so valuable , the Committee of the Kew Observatory concerted with Mr. Schwabe for the commencement last year at Kew of a series which should run parallel with his for a time , and which afterwards , when the identity or proximate identity of the two should have been established , might , it was hoped , be prolonged indefinitely through future years . Mr. Schwabe 's observations and those at Kew have accordingly been proceeding contemporaneously , and the comparison between their results during the ten months from January to October 1866 inclusive , gives reason to believe that the object will be satisfactorily attained . The number of new groups of spots observed at the two stations in the ten months is identical , and very similar , if not always quite identical , in each single month ; although , as might have been expected from the difference between the continental and insular climates , the number of days of observation at Kew is considerably less than at Dessau . The results of the first year 's experiments with the pendulums which were noticed in my last year 's Address as having been supplied to the Indian Trigonometrical Survey , have been received from Colonel Walker , IIR . A. , F.R.S. , Superintendent of the Survey . They were made by Captain Basevi at several stations where the triangulation is now proceeding . Ina letter to myself accompanying them , dated August 30 of the present year , Colonel Walker says , " Already these experiments are beginning to throw light on the subject of HIimalayan attraction ; for the observations clearly show that the force 'of gravity is less than it should be theoretically at the stations in the vicinity of the Himalayas , and that the difference between theory and practice diminishes the further the station is removed from the HIimalayas . This seems a remarkable confirmation of the Astronomer Royal 's opinion , that the strata of the earth below mountains are less dense than the strata below plains and the bed of the sea . Combining these observations with those which were used by lro . Bailey , including , I believe , all your own , the value of the ellipticity will be -.3 The general result obtained from the thirteen stations of my equatorial and arctic voyages ( 1821-1823 ) was . ' That obtained by Mr. Bailv from Captain Foster 's experi.ments in his equatorial and antarctic voyage ( 18281830 ) was 2-92 . In our Transactions of the present year we have an elaborate and valuable memoir by Mr. Abel " On the Mlanufacture and Compositiou of Gun-cotton , " pointing out the causes of the difference in the analytical results obtained by many of the earlier inquirers into its nature , and confirming its composition as determined by Crum and more fully proved by Hadow , and again stated by the Committee of Chemists who reported on Baron -von Lenk 's Gun-cotton . In pursuing these analytical inquiries , Mr. Abel has tested the methods , both synthetical and analytical , formerly employed , and has devised some modes of analysis of his own . The multiplied and varied experiments which he has made leave no room to doubt the accuracy of his results , though they differ from those of M. Pelouze . With regard to the processes of manufacture , Mr. Abel has proved by experiments , both in the laboratory and on a manufacturing scale , that Baron von Lenk 's method , although it does not at first sight present any important features of novelty , yet unquestionably ensures the attainment of greater uniformity and purity of the product , though Mr. Abel has himself suggested one or two modifications of importance . The most valuable practical result deduced by Mr. Abel from his experiments is , that the instability which has been observed in certain samples of gun-cotton , producing the gradual decomposition of such samples by prolonged keeping , is due to insufficieint purification of the material employed , in consequence of which oxidized products of small quantities of resinous and other foreign substances are formed in the manufacture , and are still retained by the tubular fibre of the cotton . These undergo decomposition , and the change extends to the mass . Many of these impurities are removed by the action of the alkaline bath upon the cotton before treating it with the nitric and sulphuric acids , and others may in great measure be dissolved by a final boiling with a weak alkaline solution . Mr. Abel 's paper is an important contribution ' towards a more complete knowledge than has hitherto obtained of the precautions which are required in the manufacture of gun-cotton in order to diminish still further both the risk of ' accidents , and the liability to injury of the material when not stored , -as it ought invariably to be when no paramount reason requires an exception , ---either under water or in a state of moisture precluding ignition . Since my Address last year little has beenl done in regard to the successful application of gun-cotton to the large ordnance employed in the public service . The desideratum for this purpose may be stated to be a form of cartridge , which with the required velocity of the projectile on quitting the piece , shall have produced an approach to an equality of strain upon every point of the bore , from the instant of ignition to that of the discharge . In the absence of a test of the degree to which this is accomplished , experiments on different forms of the cartridge are necessarily tentative , and the instruction derived from them of comparatively little value . The production of an apparatus by which the actual strain experienced in successive parts of the bore may be recorded , is in fact the first step in a scientific inquiry which should establish the proper relations between the form of the cartridge and the gun . But for the production of an efficient apparatus for this purpose , a chronoscope of greater delicacy and perfection than any we have hitherto possessed in England is indispensable . A chronoscope recently devised by Captain Schultz of the French Artillery appears , as far as can be judged previous to a practical trial , to correspond to these conditions , and to be likely to supply a means of surmounting the difficulty ; it is not improbable that it will be tried in the present year . I proceed to the award of the ATedals . The Copley Medal has been awarded to Professor Jtlius Pliicker , Foreign Member of the Royal Society , for his researches in Analytical Geometry , Magnetism , and Spectral Analysis . To an audience not exclusively mathematical it is obviously impossible to enter into details of researches which deal with geometrical questions of no ordinary difficulty . Amongst these , however , may be indicated , as especially appreciated by those who are interested in the progress of analytical geometry , his theory of the singularities of plane curves as developed in the " Algebriische Curven , " with its six equations connecting them with the order of the curves : the papers on point and line coordinates and on the general use of symbols , may also be noticed as establishing his claim to a position in the department of abstract science which is attained by few even of those who give to it their undivided attention . But Professor Pliicker has high merits in two other widely different fields of researbh , viz. in Magnetism and Spectrology ? and to these I may more freely invite your attention . Shortly after Faraday 's discovery of the sensibility of bodies generally to the action of a magnet and of diamagnetism , Professor Pliicker , in repeating some of Faraday 's experiments , was led to the discovery of magnecrystallic action , -that is , that a crystallized body behaves differently in the magnetic field according to the orientation of certain directions in the crystal . The crystals first examined were optically uniaxal , and it was found that the optic axis was driven into the equatorial position ; ( that is , of course , assuming that the magnecrystallic action is not masked , in consequence of the external form of the body , by the paramagnetic or diamagnctic character of the substance ) . New facts , discovered both by Faraday and by Pliicker himself , led him to a modification of this law , to the effect that the optic axis was impelled , according to the nature of the crystal , either into the equatorial or the axial position . This subject was afterwards followed out by Professor Pliicker into the more complicated cases in which the conditions of crystalline symmetry are such as to leave the crystal optically biaxal ; and after having recognized the insufficiency of a first empirical generalization of the law applicable to crystals of the rhombohedral or pyramidal system , and accordingly to uniaxal crystals , he was led to assimilate a crystal to an assemblage of small ellipsoids , capable of magnetic induction , having for their principal planes the planes of crystalline symmetry where such exist ; and to apply Poisson 's theory . The result of this investigation is contained in an elaborate paper read before the lloyal Society in 1857 , and published in the Philosophical Transactions for the following year . In this paper Professor Pliicker has deduced from theory , and verified by careful experiments , the mathematical laws which regulate the magnecrystallic action . These laws have not necessarily involved in them the somewhat artificial hypothesis respecting the magnetic structure of a crystal from which they were deduced ; and at the close of his memoir Professor Pliicker recognizes the theory of Professor Sir William Thomson , with which he then first became acquainted , as a sound basis on which they might be established . The laws , however , remain identically the same in whichever way they may be derived . Another subject to which Professor Plucker has paid much attention is the curious action of powerful magnets on the luminous , electric discharge in glass tubes containing highly rarefied gas . In this case the luminous discharge is found to be concentrated along certain curved lines or surfaces . He has succeeded in obtaining the mathematical definition of these curved lines or surfaces , by a simple application of the known laws of electromagnetic action , regarding an element of the discharge as the element of an electric current . With regard to the blue negative light , for instance , starting from a point in the negative electrode , he has shown that there are two totally distinct paths , one or other of which , according to circumstances , it may take , going either within the enclosed space along a line of magnetic force , or else along the surface of the glass in what he calls an " epipolic curve , " which is the locus of a point in which the inner surface of the vessel is touched by the line of magnetic force passing through that point . Angstrom appears to have been the first to notice that the spectrum of the electric spark striking between metallic electrodes through air on another gas at ordinary pressures is a compound one , consisting of very bright lines varying with the metal , and others , usually less bright , depending only on the gas . Under the circumstances which presented themselves in his experiments , the latter can frequently be but ill observed ; and the diffused light of a rarefied gas in a wide tube is but faint , and does not form very definite spectra . But Plucker found that by employing tubes which were capillary in one part , brilliant light and definite spectra were obtained in the narrow part . These spectra were observed by him with great care , and were found to be characteristic of the several gases and to indicate their chemical nature , though the gases might be present in such minute quantity as utterly to elude chemical research . It further appeared that compound gases of any kind were instantaneously , or almost instantaneously , decomposed ; at least the spectra they offered were the spectra of their constituents . In a recent memoir , which has only just been published in the Philosophical Transactions , Professor Pliicker has investigated the two totally different spectra frequently afforded by the same elementary substance according as it is submitted to the instantaneous discharge of a Leyden jar charged by an induction-coil , or rendered incandescent by the simple discharge of the coil , or else , in some cases , by ordinary flames . The two spectra show a remarkable difference in character , and are not merely different in the number and position of the lines which they show . Some phenomena which he had previously noticed receive their explanation by this twofold spectrum . This difference of spectra is attributed by Professor Pliicker , with the greatest probability , to a difference in the temperature of the flowing gas when the two are respectively produced . The discovery opens up a new field of research , the exploration of which may throw much light on the correct interpretation of celestial phenomena , especially in relation to the physical condition of nebular and cometary matter . PROFESSOR MILLER , As we have not the pleasure of the presence of Professor Plicker , I must request you , as our Foreign Secretary , to transmit to him this Medal . He will see in it the strongest evidence of the high estimation in which his labours in various lines of scientific research are held in this country ; and I trust you will also express to him the great pleasure which this award gives to his numerous friends here , some of whom have been his fellow-labourers in the same researches . A Royal Medal has been awarded to Mr. William Huggins for his Researches on the Spectra of some of the Chemical Elements , and on the Spectra of certain of the Heavenly Bodies ; and especially for his Researches on the Spectra of the Nebulae , published in the Philosophical Transactions . The researches on the stellar spectra referred to in this award were made by Mr. Huggins conjointly with our highly valued Treasurer and senior Vice-President , Dr. William Allen M[iller . The position of the latter as one of the officers of the Society and a member of its Council has forbidden the consideration of his claims to share in the honours which the Society can bestow ; and in conformity with the spirit of this , our " 'self-denying ordinance , " it would be my duty to dwell altogether on the merits of our Medallist , if , indeed , it were possible in this case to separate between the merits of the two authors of the conjoint research . This is scarcely possible , and I must be excused , therefore , if I sometimes speak of them together . Fraunhofer , Lamont , and others have at various times attempted to observe the spectra of the planets and fixed stars ; yet , though provided with powerful instruments , they obtained no important results . Mr. I-uggins and Dr. 3Tiller devised a method of seeking in the spectra of the fixed stars that evidence of the existence in them of known elementary substances which had been obtained in the case of the sun by Bunsen and Kirchhoff . A preliminary investigation of the spectra of the more important of the terrestrial chemical elements , and their direct comparison with the lines in the spectrum of common air , was undertaken by Mr. Huggins , with the view of providing a standard scale of comparison , which , unlike the solar spectrum , would be always at hand when stellar observations are possible . This was in itself a work of enormous labour ; and when completed , the spectra of the fixed stars , including those of some double stars of contrasted colours , were attacked by the two investigators ; and by a happy adaptation of comparatively moderate instrumental means , and unwearied diligence in observing and determining by micrometrical measurements the positions of objects that all but elude human vision , their researches have been rewarded by the most complete success . The spectra of the stars were compared by a method of simultaneous observation with the spectra of many of the terrestrial elements . It is upon this method of direct conmparison that the trustworthiness of the results obtained chiefly depends , and in this respect these observations stand alone . [ In 1815 Fraunhofer recognized several of the solar lines in the spectra of the Moon , Venus , and five of the fixed stars . In 1862 Donati published diagrams of three or four lines in fifteen stars . Recently Secchi , Rutherford , and the Astronomer Royal have given diagrams of the positions , obtained by measurement only , of a few strong lines in several stars . ] Eighteen stars have afforded spectra containing lines coinciding with the lines of many of the elementary substances . In thirty-seven more the spectra are full of lines which have not yet been fully compared . On extending these researches to the Nebulae , Mr. Eiuggins made the most unexpected discovery that the spectra of certain of these bodies are discontinuous , consisting of bright lines only , whence he drew the conclusion that " in place of an incandescent solid or liquid body transmitting light of all refrangibilities through an atmosphere which intercepts by absorption a certain number of them-such as our sun appears to be we must probably regard these objects , or at least their photo-surfaces , as enormous masses of luminous gas or vapour . For it is alone from matter in a gaseous state that light consisting of certain definite refrangibilities only , as is the case with the light of these nebulae , is known to be emitted . " During the last two years Mr. Huggins has examined the spectra of more than sixty nebula and clusters . This examination shows that these remarkable bodies may be divided into two great groups : viz. 1st , true or gaseous nebulae , which furnish a discontinuous spectrum , consisting of two or three bright lines only ; and 2nd , what we may distinguish as spurious nebule , or nebulous matter with clusters , which give a spectrum apparently continuous . Of the latter group a large proportion show signs of resolvability into clusters by telescopes of high power . In the present year also Mr. Huggins has made a remarkable observation upon the small comet , known as comet No. 1 , 1866 . He ascertained that the minute nucleus gave a gaseous or discontinuous spectrum ; whilst the spectrum of the coma , as though formed by suspended particles which reflected solar light , gave a continuous spectrum . Since the publication of these results by Mr. Iuggins , our investigators have examined with great care the spectrum of the star which is either new or has greatly increased in brilliancy in Corona borealis , and have found that that star has a spectrum of absorption , and also a gaseous spectrum of which hydrogen is probably the source . They have also connected , in one instance at least , the change in a variable star with a variation in its spectrum . Discoveries like these , which acquaint us not only with the constituents of the heavenly bodies but also with their state of aggregation , are of the nature of those which occur only once in the course of centuries , -like the discovery of the satellites of planets , of solar spots , or of double stars , and have the strongest possible claim on the Royal Society for such honours as the Society has at its disposal . AIR . -IUGGINS , It gives me the greatest pleasure to present you with this Medal : a testimonial of the very high estimation in which your successful labours ( conjointly with Dr. Miller ) are held by the Society , which has the satisfaction of regarding you as one of its most distinguished Members . You are at an age at which you may reasonably indulge in the prospect of having a long career before you ; yet , however long , it will scarcely exhaust the noble field of research which you have opened for yourself , and which is one in which you are quite sure to be accompanied by the sympathy of men of science throughout the world . A Royal Medal has been awarded to Mr. William Kitchen Parker for his researches in Comparative Osteology , and more especially on the Anatomy of the Skull , as contained in papers published in the Transactions of the Zoological Society and the Philosophical Transactions . Mr."Parker has for several years past made investigations of great extent and distinguished merit among the Foraminifera , the results of which are embodied in Memoirs published by him from 1859 to 1865 , in conjunction with Professor Rupert Jones and with Dr. Carpenter in the Annals of Natural Iistory , the publications of the Ray Society , and the Philosophical Transactions . The award of a Royal Medal to Mr. Parker has been based , however , not so much on his work in this department of zoology as on his labours in a very different and much more difficult branch of anatomy , Vertebrate Osteology . In 1860 Mr. Parker published a memoir " On the Osteology of Balceniceps Rex , " and in 1862 another " On the Osteology of the Gallinaceous Birds and Tinamous , " in the Transactions of the Zoological Society ; while a third still more important memoir , on the " Skull of the Ostrich Tribe , " was read before the the Royal Society in March 1865 , and is now published in the Philosophical Transactions . In these elaborate andbeautifully illustrated memoirs , Mr. Parker has not only displayed an extraordinary acquaintance with the details of Osteology , but has shown powers of anatomical investigation of a high order , and has made important contributions towards the establishment of the true theory of the vertebrate skull . M* R. WILLIAM KITCHEN PARKER , I present you with this Medal in testimony of the high esteem in which your investigations are held by those of our body who are qualified to appreciate them , and who look at once with approval and with expectation at the increased and still increasing interest of the communications contributed by you to our Transactions . The Council have awarded the Rumford Medal to M. Armand IHippolyte Louis Fizeau for his Optical Researches , and especially for his Investigations into the Effect of Heat on the Refractive Power of Transparent Bodies . In 1849 M. Fizeau rose into celebrity as the experimenter who first succeeded in measuring the velocity of light by observations limited to objects on the surface of the earth . He noted the time required for the passage of light from the place of the observer to a mirror , normal to the path of the light , 8633 metres distant , and back again , by means of a wheel having 720 teeth revolving rapidly . When the wheel made 126 revolutions in 10 seconds , the light that had passed through the notch between two teeth towards the mirror was stopped completely on its return , after reflexion , by the second of the two teeth ; showing that the light had travelled 17,266 metres while the wheel had revolved through half the angle subtended at its centre by the distance between the summits of two adjacent teeth , or -rrnT second . In 1859 he wrote a remarkable memoir , " Sir un experience qui parait demontrer que le mouvement des corps change la vitesse avec laquelle la iumire se propage dans leur int6rieur . " I-his " Methode propre a rechercher si l'azimuth de polarisation du rayon refracte est influence par le mouvement du corps refringent " ( 1860 ) involves such complicated arrangements that great hesitation was felt about accepting the results . But whoever has seen his experiments on the expansion and the alteration of the refrangibility of bodies when heated , is not disposed to question any conclusions regarded by Fizeau himself as well founded . In 1862 he published " Recherches sir les modifications que subit la vitesse de la lumi & re dans le verre et plusieurs autre corps solides sous l'influence de la ehaleur , " the first of a series of memoirs on the change of dimensions and refractive powers of various kinds of glass , and many crystallized substances . On the 23rd of May , 1864 , he read before the Institut " ' Recherches sir la dilatation et la double refraction du cristal de roche echaiff ; " and on the 21st and 28th of May , 1866 , " ( M6 oires sir la dilatation des corps solides par la chaleur . " In these observations he has availed himself of the possibility of forming Newton 's rings with the monochromatic sodium light when one of the interfering rays is 52,205 waves in advance of the other , a fact which , conjointly with M. Foucault , he announced in 1849 . Using the length of a wave of sodium light ( 0'0005888 millimetre ) as the standard of measure , the position of a ring being observable to within I-i of the distance between two consecutive rings , the variation of the distance between two surfaces producing the Newton 's rings can be measured to within -1s T millimetre . A plate of the substance to be experimented on ( let us suppose it to be fluor ) , usually from 10 to 15 millimetres thick , bounded by parallel plane surfaces , rests upon the platform of a metal tripod ( the metal was steel in the earlier observations , platinum with -T & of iridium in the later ) . The feet of the tripod are screws of equal lengths terminating above in obtuse points . On these points , at a distance of about gmillimetre above the upper surface of the fluor , rests a plate of glass . By counting the number of rings or bands that pass over a mark on the upper surface of the fluor during a given change of temperature , the corresponding variation of distance between the lower surface of the glass and the upper surface of the fuor is given , and the expansion of the metal being known by a similar process , the expainsion of the fluor is found . The Newton 's rings formed between the two surfaces of the fluor depend upon its thickness and its refractive power . The number of rings that pass over the mark on the fluor during a given change of temperature bei ng observed , and its expansion having been found by the preceding observation , the change of its refi'active power due to the change of temperature becomes known . , In this way M. Fizeau obtained several very unexpected results . Of these a few may be noticed . The indices of refraction of most substances were found either to increase or to remain unaltered with an increase of temperature , but in fluor the index of refraction diminishes with an increase of temperature . Diamond , cuprite , and beryl have a maximum density , like water-diamond at -420 ? 3 C. , cuprite at -4 ? '3 , and beryl at -4 ? '2 . Beryl , when heated , unlike calcite , contracts in the direction of its axis , and expands in a direction making right angles with the axis . Quartz , rutile , cassiterite , spartalite , corundum , and hematite were found to expand in every direction when heated ; but in each case the expansion in the direction of the principal axis was different from the expansion in a direction at right angles to the principal axis . M. Fizeau is also the author of many other important researches-on Moser 's images , on photography , on the automatic engraving of photographic images on copper , on the interference of rays of heat , on electricity and the velocity of its propagation , and on the position of the plane of polarization of light reflected from striated metallic surfaces . PROFESSOR MILLER , I have to request you to transmit this Medal to Monsieur Fizeau , in testimony of our interest in his researches and our high respect for his merits , which you have yourself been especially instrumental in placing in a clear light before the Council . On the motion of Vice-Chancellor Sir W. Page Wood , seconded by Mr. Hog , it was resolved , -"That the thanks of the Society be returned to the President for his Address , and that he be requested to allow it to be printed . " The Statutes relating to the election of Council and Officers having been read , and Mr. Balfour Stewart and Mr. C. V. Walker having been , with the consent of the Society , nominated Scrutators , the votes of the Fellows present were collected ; and the following were declared duly elected as Council and Officers for the ensuing year : President.-Lieut.-General Edward Sabine , Il . A. , D.C.L. , LL. D. Treasurer.-William Allen Miller , 3LD . , LL. D. Seererie . J William Sharpey , M.D. , LL. D. . George Gabriel Stokes , Esq. , M.A. , D.C.L. , LL. D. Foreign Secretary.-Professor William Hallows Miller , M.A. , LL. D. Other iMember s of the Council.-Lionel Smith Beale , Esq. , M.D. ; William Bowman , Esq. ; Commander F. J. Owen Evans , R.N. ; Edward Frankland , Esq. , Ph. D. ; John HIall Gladstone , Esq. , Ph. D. ; William Robert Grove , Esq. , M.A. , Q.C. ; William Huggins , Esq. ; Thomas Henry Huxley Esq. , LL. D. ; William Lassell , Esq. ; Professor Andrew Crombie Ramsay , LL. D. ; Colonel William James Smythe , R.A. ; William Spottiswoode , Esq. , MA . ; Thomas Thomson , M.D. ; William Tite , Esq. ; Vice-Chancellor Sir W. P. Wood , D.C.L. ; The Lord Wrottesley , MI . A. , D.C.L. The thanks of the Society were voted to the Scrutators . RecciPts and Payments of the Royal Society between Decemnber 1 , 1865 , and November 30 , 1866 . ? s. d. Balances on hand ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... . . 15 9 Annual Subscriptions , Admission Fees , and Compositions ... 1697 16 0 ents ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 253 18 0 Dividends ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 1541 3 Ditto , Trust Funds ... ... ... ... ... ... ... ... ... ... ... ... ... ... 23 06 Sale of Transactions , Proceedings , &c. ... ... ... . 383 02 Repayiments ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... . . 96 30 Prof. Sylvester , repaid to Donation Fund ... ... ... ... ... ... ... 25 00 2-'4295 16 11\~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~--~--~ ? - ? r ? .~ ? s. d. Balance due to Banl kers ... ... ... ... ... ... ... ... ... ... ... ... . 135 7 10 Salaries , Wages , and Pension ... ... ... ... ... ... ... ... ... ... ... . . 1031 12 0 The Scientific Catalogue ... ... ... ... ... ... ... ... ... ... ... ... 178 17 6 Books for the Library and Binding ... ... ... ... ... ... ... ... ... 33 16 6 Printing Transactions and Proceedings , Paper , Binding , Engraving , and Lithography ... ... ... ... ... ... ... ... ... ... ... 1334 14 8 General Expenses ( as per Table subjoined ) ... ... ... ... ... ... 483 92 Donation Fund ... ... ... ... ... ... ... ... ... ... ... ... ... 80 00 Wintringham Fund.5 ... ... ... ... ... ... ... ... ... ... . 35 50 Copley Medal Fundcl ... ... ... ... ... ... ... ... ... ... ... 4 15 0i J. Clerk Maxwell , Bakerian Lecture ... ... ... ... 4079 Rev. Dr. Stebbing , Fairchild Lecture ... ... ... ... 2 18 9 Croonian Lecture ( Poor of St. James 's Parish ) 2 19 Oj 3629 15 5 Balance at Bank ... ... ... ... ... ... ... ... ... ... ... ... ... . . 638 81 Balance of Catalogue Account ... ... ... ... ... ... ... ... ... ... ... ... 18 19 9 , Petty Cash Account ... ... ... ... ... ... ... ... ... ... ... ... ... 8 13 8 ? 4295 16 11 WILL LEN ILLIAM ALE LER , Treasurer . Esetaes and Property of the Royal Society , inchding Trust FZunds . Estate at Mablethorpe , Lincolnshire ( 55 A. 2 R. 2 P. ) , ? 126 Os . Od . per annum . Estate at Acton , Middlesex ( 34 A. 3 I. 11 p. ) , 2110 Os . Od . per annum . Fee farm near Lewes , Sussex , rent -19 4s . per annum . One-fifth of the clear rent of an estate at Lambeth HIill , from the College of Physicians , ? 3 per annum . ? 14,000 Reduced 3 per Cent. Annuities . ? 28,969 15s . 7d . Consolidated Bank Annuities . ? 513 9s . 8d . New 2 ' per Cent. Stock-Bakerian and Copley iedal Fund . 0 < 0 tr 34 Dr. I ScientZfi BRelief Fund . Investments up to July 1865 , New 3 per Cent. Annuities ... ... ... ... ... ... ... ... ... 6052 17 8 ? 6052 17 8 ? s. . d " Balance ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 181 10 8 By Grants Subscriptions 13 13 0 Balance Dividends ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 178 11 2 ? 373 14 10 Statement of Income and Expenditure ( apart from Trust Funds ) during the Year encling November 30 , 1866 . 'f ' 7 Annual Subscriptions ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... Admission Fees ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... Compositions ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... . . R ents ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... Dividends on Stock ( exclusive of Trust Funds ) ... ... ... ... , on Stevenson Bequest ... ... ... ... ... ... ... ... ... ... Sale of Transactions , Proceedings , &c. ... ... ... ... ... ... ... . . Chemical Society , for Proceedings , 1865-66 ... ... ... ... . . Chemical Society , Tea Expenses ... ... ... ... . 16 78 Linnean Society , Tea Expenses ... ... ... ... ... 16 7 8J Geographical Society , Gas at Evening 84 81 Meetings ... ... ... ... ... ... ... ... ... ... . . CambridgeLocalExamination Committee , Gas 480 St. George 's Rifles-Gas ... ... ... ... ... ... ... ... 15 O 1111 16 0 170 00 416 00 253 18 0 997 3 10 544 65 383 02 50 00 32 15 4 13 78 Income available for the Year ending Nov. 30 , 1866 ... ... 3972 75 Expenditure in the Year ending Nov. 30 , 1866 ... ... ... . . 3364 9 10 > Excess of Income over Expenditure in the Year ending ? 607 17 7 Nov. 30 , 1866 ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... Cr . ? s. d. 160 00 213 14 10 ? 373 14 10 - ? 9 s. d. Salaries , Wages , and Pension ... ... ... ... ... ... ... ... ... ... ... 1031 12 0 The Scientific Catalogue ... ... ... ... ... ... ... ... ... ... ... ... ... . 178 17 Books for the Library ... ... ... ... ... ... ... ... ... ... ... ... ... ... . 197 50 Binding ditto ... ... ... ... ... ... ... ... ... ... ... ... .138 11 6 Printing Transactions , Part II . 1865 , and 350 18 9 Part I. 1866 ... ... ... ... ... ... ... ... ... ... ... 18 Ditto Proceedings , Nos. 78-86 ... ... ... ... ... 276 14 9 Ditto Miscellaneous ... ... ... ... ... ... ... ... ... ... 76 60 1334 14 8 Paper for Transactions and Proceedings ... 228 16 5 Binding and Stitching ditto ... ... ... ... ... ... ... 78 25 Engraving and Lithography ... ... ... ... ... ... 323 16 4 Upholstery , Cleaning , and Repairs ... ... ... ... ... ... ... ... ... 48 88 Miscellaneous Expenses ... ... ... ... ... ... ... ... ... ... ... ... ... . . 39 90 Coal , Lighting , and Gas-fittings ... ... ... ... ... ... ... ... . . 136 69 Tea Expenses ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... . 49 21 Fire Insurance ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 28 11 6 Donation:-Mablethorpe Schools ... ... ... ... ... ... ... ... ... ... 220 Taxes ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 8 19 2 Taxes ... . 8 19 2 Law Expenses ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... . . 126 7 10 Advertising ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 9 15 6 Postage , Parcels , and Petty Charges ... ... ... ... ... ... ... ... ... 34 6 8 ? 3364 9 10 WILLIAM ALLEN MILLER , Treasurer . o c-1I I o. . The following Table shows the progress and present state of the Society with respect to the number of Fellows : Patron Having Paying Paying and Foreign . com ? 2 12s . ? 4 Total . Royal . pounded . annually . annually . November 30 , 1865 . 6 47 309 3 274 639 Since elected ... ... ... . . +3 +6 ... ... +9 +-18 Since readmitted ... ... ... ... ... ... . 1 +1 Since compounded ... ... ... ... ... ... . . -1 Since deceased ... . -1 1 -14 . -15 -31 Since defaulter ... ... ... ... ... ... ... ... ... . -1 -1 November 30 , 1866 . 5 49 302 3 267 626
112637
3701662
Discussion of Tide-Observations at Bristol. [Abstract]
289
290
1,866
15
Proceedings of the Royal Society of London
T. G. Bunt
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
2
17
434
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112637
null
http://www.jstor.org/stable/112637
null
null
Meteorology
78.488232
Tables
15.131
Meteorology
[ 47.493534088134766, 31.879379272460938 ]
I. " Discussion of Tide-Observations at Bristol . " By T. G. BUNT , Esq. Communicated by the Astronomer Royal . Received October 24 , 1866 . ( Abstract . ) This Paper contains the results of a Discussion of about 19,000 observations of Times and Heights of Iigh Water at Bristol , for the purpose of obtaining the Empirical Laws of the Diurnal Inequalities of the Times and HIeights , and of the Solar Inequality of the Times , of the tides at that port . Curves on Diagrams which accompany the Paper exhibit the results . The Observations were taken by a Self-registering Tide-Gauge , the Clock of which has from the first been regulated by transit observation . The Diurnal Inequalities of the tides at Bristol are not large , that of time averaging only 2 minutes ( earlier or later ) , and that of height 2k inches ( greater or less ) . Although it was stated by Sir JohnW . Lubbock ( in 1839 ) that the diurnal inequality in time is too minute to be observed on our coasts , the slightest examination of the Diagram ( No. 4 ) will be sufficient to show that this remark is inapplicable to Bristol . On this diagram are laid down the times and heights of tide registered there during six months of the year 1865 . In consequence of the tranquil state of the weather , the agreement of the observed with the predicted times was unusually close ; the average error in time , during the six months , being only 2minutes , and for six weeks less than 1'9 minute . The diurnal inequality , of time as well as of height , is throughout the diagram most conspicuous ; and the agreement of the calculated with the observed inequality close and satisfactory . For each of the Diurnal Inequalities , the residues , or errors , of the calculated Times and Heights were arranged for every half month , and for each of the twenty-four hours of Lunar transit , making ( 24 x 24 = ) 576 Groups . The averages of these , laid down in Curves , are shown in Diagrams No. 1 and 2 . Diagram No 3 shows the Solar Inequality of Time , obtained in a similar manner , together with curves of the separate effects of the Solar Parallax and Solar Declimation . A sheet from the Tide-Gauge Cylinder has also been sent , as a specimen of the regularity of the registered Curves in tranquil weather .
112638
3701662
On the Heating of a Disk by Rapid Rotation in vacuo
290
299
1,866
15
Proceedings of the Royal Society of London
Balfour Stewart|P. G. Tait
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0068
null
proceedings
1,860
1,850
1,800
10
160
4,505
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112638
10.1098/rspl.1866.0068
http://www.jstor.org/stable/112638
null
null
Thermodynamics
30.272319
Fluid Dynamics
23.42473
Thermodynamics
[ 17.496538162231445, -29.11448860168457 ]
II . " On the Heating of a Disk by rapid Rotation in vacuo . " By BALPOUR STEWART M.A. , F.R.S. , and P. G. TAIT , M.A. ( Continuation of a Paper read before the Royal Society on June 15 , 1865 , and published in the 'Proceedings . ' ) Received October 30 , 1866 . 16 . The apparatus and certain preliminary experiments having been described in the previous paper , the authors now proceed to relate what further experiments have been made . In the preliminary experiments it was conclusively shown ( art . 8 ) that the effect on the pile caused by rotation of the disk was due to radiant heat , and also ( art . 9 ) that this effect was not due to the heating of the rock-salt , which in most of the experiments was placed before the mouth of the cone . It was also rendered probable that the effect was not due to radiation from heated air , by the two following considerations:(1 ) Because in order that nearly dry air of such a tenuity might give such a radiation it would require to be heated enormously . ( 2 ) Because when the lampblack was removed from the aluminium disk , leaving it a roughl metallic surface , the indication afforded by the galvanometer was reduced to about one-fourth of the amount with the blackened disk . The following observations tend to strengthen this proof:(3 ) The heating effect is the same in hydrogen or in coal-gas as in air , although there is no question that the absorptive , and therefore the radiative power of coal-gas is much greater than that of air . This is shown by the following sets of experiments , which were made with the blackened aluminium disk insulated with ebonite , and with rock-salt in the cone . , t Ijv Z ? 5 Heat indication . |oJ | . ** '3 J_ L__ _____ Natulre Tensio ? , i blackened aluminiumn disk than from an unblackened one does not prove that this heating effect may not be due to air , since the blackened surface may be imagined to lay hold of the air more than the metallic one . But the following sets of experiments prove that the heating effect of the aluminiium disk with both sides blackened is the same as when only one side is blackened. . 4 . , . 0 §§. . OA ' ? e X. 2 30 20 0'9 1-1 Disk blackened on one side . XIII . 3 30 20 0'8 0-4 Disk blackened on both sides . It would therefore appear to be proved that in these experiments the heating effect is due to the increased temperature of the disk . 17 . Before proceeding further it may be advisable to detail some experiments made with an ebonite disk - , inch thick . In these experiments care was taken that the ebonite should have the same temperature throughout its thickness , so that there might be no flow of heat from the interior to the surface , or vice versa . The experiments were made with rock-salt in the cone . , ... ' . ; * | |.atu1ri r Tension 4| 4 . 4-4^ tl e 1i '* Nature of of gas , in o oD gas . inches . ff XIV . 3 30 20 32 air 11 XV . 1 30 20 30 air 0-26 XVI . 1 30 20 31 air 11 XVII . 2 30 20 28-5 air 0-26 XVIII . 2 30 20 28-5 air 0-25 XIX . 3 30 20 29 hydrogen 0-25 90 From these experiments it may be taken for granted that the heat indication given by an ebonite disk is , like that from an aluminium disk , independent both of the density and chemical constitution of the residual gas . It is also highly probable that the unknown cause of the heating effect is the same for both disks . 18 . To return now to the aluminium disk , it may be shown that the heating of this disk is not caused by revolution under the earth 's magnetic force ; for ( 1 ) the following calculation , kindly furnished by Professor Maxwell , shows that the heating effect due to this cause would , for the aluminium disk 1 of an inch in thickness , amount , under the circumstances of rotation , only to f-i -1 of a degree Fahr. , whereas the observed effect is more than half a degree . An ellipsoid , semiaxes a , b , c , revolves about the axis c with velocity w , 22 in a uniform magnetic field . To find its electrical state at a given instant . At the given instant let the axes of x , y , z coincide with a , b , c ; then using the notation in the paper on the Electromagnetic field * , P-t=wyx-a=-P , Q=PWYY--y=qP , i= --a , ( / 3y+ax)-a ? PQ electromotive force , ary magnetic intensity,.b electric tension , e=coefficient of magnetic induction =I for everything but iron , p , gq , r electric currents , p=resistance of cubic unit of volume . The condition of the currents being confined to the ellipsoid , is a2+ 62+'= Solving , we get p( a'2a pw 62u / ax pie \ 2Pp a-}-q2 p62 qp ac 2 C2 62C2 I= 2y('2 +1 ' ? y')(^ @+a 6+c2 C ) + C. This is the complete solution . The heat ( measured as energy ) produced in unit of volume in unit of time is p(p2 +q2 + 22)* The whole heat produced in the ellipsoid in unit of time is 47r f2 aac3 a / a ? 22 } 1l , p { a " W+2 ++ c ' 4r It2 alea If a=b , this is p a+e ( a2+p2 ) . If c is small compared with a , it becomes 47r A2 -5 p-2-a2C3(2 -_/ 2- ) . If the axis is horizontal , a 2+ -3IP2 sin2 0+ V2 , where H=horizontal magnetic force , and V=vertical magnetic force , and 0=angle between the axis of rotation and the magnetic meridian , a=radius and c half the thickness , w= 27rn , where n denotes the revolutions per second ; ip= 1 ; p is the resistance of unit length and unit section . Now , the resistance of 1 metre long and 1 millimetre diameter =4P10G-=00375 X 107 7r r 32 for aluminium in metrical units by Matthiessen , or-= p is the same for metrical and for British measure . At Kew horizontal force=3'81 , dip 68 ? '10 ; 0=90 ? in the experiments.a . a2+2= 104-8 British measure . The revolving body is not an ellipsoid but a cylinder , equally thick 15 throughout ; to correct for this we shall put -2 c for c3 . We get for the energy converted into heat by electrical action per second 12'91 in grain-foot-second measure . Now 772-= energy required to raise 1 grain of water 1 ? Fahlr . 70,000 The disk =-- ' 22 grain of water,. . energy corresponding to 1§ 32'2 = 772 x -16 x 15400 , 12'91 12'91 or rise of temperature per second= 1540x 15400= 23716000 degree Fahr. or about 61270 degree in 30 seconds . This is when the heat is uniformly distributed through the thickness of the disk , which it will be in less than thirty seconds . If there were no conduction , the rise of temperature at the surface would be about twice the value found above . ( 2 ) It would appear from the above formula that the heating effect due to this cause should increase with the thickness of the disk . The following experiments show that , on the contrary , the heating effect , as regards temperature , diminishes as the thickness of the disk increases . 0 00 0 . _"o~ ( 1 , Z P- : C ) , ~ . Pp0 000 804 4-ec ~0 0C C 0-00 XIII . 3 30 20 0-8 0-4 Aluminium disk nl inch thick . XX . 3 30 21 1-7 04 Aluminium disk l inch thick . ( 3 ) The heat indication afforded by an ebonite disk is against the conclusion that this effect is due to rotation under the earth 's magnetic force . It would therefore appear to be proved that in these experiments the increased temperature of the aluminium disk is not due to rotation under the earth 's magnetic force . 19 . It might perhaps be said that the heating of the disk may be due to heat conducted from the bearings into the disk and then distributed outwards ; and this conjecture will require to be examined , since the bearings are , no doubt , heated by friction during the motion . This heating effect on the bearings was measured by means of a very delicate thermometer , which was inserted into a small hole in the bush through which oil is supplied to the spindle , and made to be in metallic contact with the sides of this hole ; the mean of three observations made the heating effect at the spindle due to rotation to be 4 ? Fahr. In the next place , the aluminium disk , separated from its metallic spindle by the ebonite washer , and in every respect the same as when made to rotate , had its spindle heated artificially by a mercury bath , generally at least 40 ? Fahr. above the previous temperature . After the lapse of two minutes the effect upon the pile was hardly perceptible-not more than five divisions . 1 ) It would appear from this experiment that the heating effect ob served in rotation cannot be due to heat conducted from the bearings through the ebonite washer , since a temperature difference between the bearings and the disk ten times greater than that produced by rotation causes a heating effect at least six times less than that caused by rotation in a somewhat less time . ( 2 ) The ebonite washer used to prevent the heat of the bearings from reaching the aluminium disk , is a cylindrical disk , its thickness being twotenths of an inch , and the area of one of its faces 3 15 square inches . It is shielded behind by a brass disk , of similar size , which brass disk being near the bearings , and metallically connected with them , wte may suppose to have the same temperature as the bearings . Thus one face of the ebonite washer is in contact with brass , having the temperature of the bearings , while the other is in contact with the aluminium disk . Supposing that this washer , used to protect the aluminium disk from the heat of the bearings , was of iron instead of being of ebonite , we can calculate approximately from Principal Forbes 's determinations of the absolute conductivity of this metal , how much heat would be conducted across the washer during the experiment . According to these observations , if a cube of iron whose side is one foot , have one of its faces kept permanently at a temperature 1 ? C. higher than the opposite face , the quantity of heat conducted across in one minute will be '011 unit nearly , a unit denoting the amount of heat required to raise a cubic foot of water 1 ? C. Since in these observations both the temperature difference and the unit are expressed in the same thermometric degrees , we may , if we choose , substitute degrees Fahr. for degrees Centigrade in the above expression for conductivity . Now , if we assume as an approximation that during the whole experiment of rotation the heat conducted across such a washer is the same as if for one minute the temperature difference between both sides of the washer were kept at 2 ? Fahr. , and if we make allowance for the surface and for the thickness of the washer , we obtain the following expression as approximately representing the heat conducted across the washer during the experiment , 3'15 12 Heat=--01 x2xX =302 T08 unit nearly , 144 -2 where the first factor is on account of the double temperature difference , the second on accountt of the surface , and the third on account of the thickness . But a unit of heat in the above expression denotes the amount necessary to raise a cubic foot of water ( or nearly 1000 ounces ) 1 ? Fahr. Now the weight of the disk is 10*5 ounces , and its specific heat is 0-22 . Hence the above amount of heat will raise the disk 1000 1 *028 x x10 -= 12 ? Fahr. in temperature . 10'5 '22 Hence we see that if the material of the washer had been of the metal bismuth , of which the conductivity is 7 times less than that of iron , and if we suppose the circumstances of the experiment to be equivalent to a temperature difference of 2 ? Fahr. between the two sides of the washer lasting for one minute , then the quantity of heat conducted across the washer will be a little greater than that observed . But the conductivity of ebonite is no doubt very much less than that of bismuth , and therefore on this account we cannot suppose that the heating effect observed is due to conduction . ( 3 ) In this investigation no account has been taken of the unequal distribution of temperature from the centre to the circumference of the disk , the tendency of which would be to diminish the effect upon the pile ( which was directed to the circumference of the disk ) of the heat passing through the washer ; and indeed , when this element is taken into account , it is not surprising to find , as was actually the case , that in some preliminary experiments , where the disk was metallically connected with the spindle , the effect was not greater than with the ebonite washer . ( 4 ) The short time in which the effect attains its maximum value is against the supposition that it is caused by conduction from the bearings . ( 5 ) The fact that ( as we shall afterwards see ) the temperature effect in three aluminium disks of different thicknesses is inversely proportional to the thickness , is also against this supposition . ( 6 ) And so is the fact that a heat-effect obeying apparently the same laws , holds for an ebonite disk in which there is but a very feeble conduction . On the whole , therefore , we cannot suppose this effect to be due to conduction , or at least we must conclude that the effect of conduction constitutes only an exceedingly small fraction of that observed . 20 . Itwas suggested to the authors by Professor Stokes and by Mr. Grove , that the effect might be due to vibrations of the disk , the energy of which , owing to the viscosity of the disk for such vibrations , might ultimately become converted into heat ; and it is necessary to examine this question . ( 1 ) The thickest aluminium disk was found to be out of truth not more than -015 inch on each side . Hence , the thickness of this disk being *05 inch , when turned with moderate rapidity , its apparent thickness should be -015 + 05 + 01 == 08 ; and experiment showed that when turned very fast , its apparent thickness was no greater . The greatest possible range of vibrations of the disk at its circumference could not , therefore , be more than '015 inch on either side of the position of rest . Again , it was ascertained by means of the note given by this disk , that it vibrates about 250 times per second . Let us suppose the whole mass to have the same range of excursion ( this will of course increase the result ) , the equation of vibration ( not allowing for loss by viscosity ) is x='015 cos nt and also time of vibration 2rw 1 -nz 250 ' Hence n=500 x314-=1570 , say , cdx in . in..* " =--'015x 15 70 sin nt,. . greatest velocity =23'55 , or say 2 feet per second . IHence the energy of this motion in foot pounds , =weight of disk in pounds x ' 2g =weight of disk in pounds through -Lof a foot . But an approximate experiment performed by causing the disk to ring , and noticing how long the sound lasted , would seem to show that probably the energy of vibration of the disk diminishes at first , and therefore constantly ( if it is maintained ) at the rate of the whole in 3 seconds . Hence in 30 seconds it loses 10 times as much as the whole ; that is to say , in 30 seconds the heat produced cannot be greater than that due to the energy produced by the disk falling under gravity through l-o of a foot . Reducing this to its heat-equivalent , the greatest possible heat effect due to vibration during 30 seconds rapid turning will be less than 10 I11 Far . ^X ---XO Fahlar_ 16 772 x22 272 which is a very small fraction of the effect observed . ( 2 ) The thin aluminium disk was out of truth about *02 inch on each side . Its note of vibration was as nearly as possible one octave lower than that of the thick disk , while its coefficient of viscosity was somewhat greater , say in the proportion of 3 to 2 , than that of the thick disk . On the supposition that the heat generated is due to vibration , if we call the heat generated during 30 seconds in the thick disk =1 , then that generated during the same time in the thin disk ought to be / .027 3X I xx- , where the first factor is on account of difference of time of vibration , the second on account of difference of range , the third on account of difference of mass , and the fourth on account of difference of viscosity . But the heating effect ( as far as quantity of heat is concerned ) produced in the thin disk is as nearly as possible the same as that produced in the thick disk . This fact is therefore against the hypothesis that the heating effect is due to vibration . ( 3 ) In order to estimate the effect ( if any ) of want of truth in the disk , the thick aluminium disk was purposely put out of truth about 3k times srlv alrlrh+~lriLLl~+Ll l*IJ+~VI+~ lUrVIL13( CCV ldL V ~iU~~ C~JUt ? t ; its usual amount ; but the heating effect was as nearly as possible the same in both cases , being 32 divisions of the scale in both . On all these grounds it would appear that the heating effect cannot be due to vibration of the disk . 21 . It is hardly necessary to mention that the heating effect cannot be due to radiation and convection from the wheelwork , which is no doubt slightly heated during the experiment , for the mass of this metallic matter is so great , that we cannot imagine it to be heated more than 10 Fahr. Now the radiation from this against the back of the disk may certainly be neglected , while the convection must be very small , since in the experiments the pressure of the air was very small . Besides , the heating effect , as will be seen shortly , was found to be independent of the pressure . 22 . It has thus been shown that the disk is heated during the experiment , and that this heating effect(1 ) Is not due to rotation under the earth 's magnetic force ; ( 2 ) Is not due to conduction of heat from the bearings ; ( 3 ) Nor to radiation or convection from the wheelwork ; ( 4 ) Nor to vibrations of the disk . And in view of the large and constant nature of this heating effect it may be asserted that it cannot be sensibly due , either to one of these causes singly , or to their combined effect . 23 . It will now be sliown that the heating effect is independent both of the density and chemical constitution of the residual air and vapour around the disk . In art . 16 , if we compare together the 7th , 8th , 9th , 10th , 11th , and 12th sets of experiments , we shall see that the heating effect was sensibly the same , whether the residual gas was atmospheric air , or hydrogen or coal-gas . As hydrogen diffuses very quickly , it might perhaps be supposed that when heated by rotation it might find access to the pile through the rocksalt cover more easily than heated atmospheric air , so that while the whole effect might appear the same in hydrogen as in air , yet only part of that in hydrogen might be due to radiant heat , the remainder being due to heated gas which had obtained access to the pile . This was , however , disproved by an experiment , which showed that by'blackening the interior of the cone , the effect upon the pile was just as much diminished in a hydrogen vacuum as in an air vacuum ; and hence in both cases the whole effect is due to radiant heat . But , besides the residual gas , it may with truth be supposed that there is always more or less of aqueous vapour , and also a little of the vapour of oil , and perhaps of the vapour of mercury in the receiver . As regards the hygrometric state of the residual air and its influence on the disk , this would appear to be of the following nature:(1 ) When the vacuum has just been made , there is generally a hygrometric difference between the air and the surface of the disk , on account of which there is a strictly temporary effect , either in the direction of heat or cold , at the surface of the disk , owing probably to condensation or evaporation of small quantities of aqueous vapour ; but this effect disappears the moment the motion is stopped , leaving behind the permanent effect apparently unaltered . ( 2 ) This temporary effect disappears when the disk has been left for some hours in the vacuum . Next , with regard to vapour of oil , we cannot suppose its effect to be so large or so different in character and constancy from that of aqueous vapour as to account for the effect observed . Add to this that the effect takes place with an uncoated metallic disk probably to the same extent as with a coated one . The same remark may be made with regard to vapour of mercury . The effect would therefore appear to be independent of the chemical nature of the residual gas and vapour around the disk . In order to prove that this effect is also independent of the pressure of the residual gas , it is only necessary to refer to the whole body of experiments which have been described , to see that between 4 inches and 0'25 inch there is no perceptible variation in the effect observed . 24 . The following generalization may now be made:(1 ) If a perfectly true aluminium disk ( without vibrations ) be made to rotate in a vertical plane at the earth 's surface , after the manner herein described , there will be an increase of the temperature of the disk , which is not due to communication of heat from the bearings or machinery , nor to the earth 's magnetic force . ( 2 ) This heating effect is independent of the density and chemical constitution of the residual air and vapour which surround the disk . ( 3 ) It is probable that the quantity of heat developed in disks of similar extent of surface and similar circumstances of motion is the same . For , in the first place , the quantity of heat developed in three aluminium disks , *05 , '0375 , '025 of an inch in thickness respectively , would appear to be the same , the relative thermometric effect for these disks varying inversely as their thickness , and being in the following proportions , 30 , 43 , 60 , as determined by one complete set of experiments . Again , the quantity of heat developed in the thick aluminium disk , with its surfaces both uncoated , was probably the same as when one surface was coated and one left bare , or as when both surfaces were coated . 25 . The authors will'not attempt here a further generalization , but they would desire to make one remark . In absence of definite knowledge of the nature of that mnedium which transmits radiant light and heat , it might be supposed possible that when a radiant body is in rapid motion , the intensity of its radiation is somewhat increased . But if we bear in mind that in these experiments the effect was observed after bringing the disk to rest , and that the temporary effect during rotation sometimes observed can probably be otherwise accounted for , we are forced to conclude that , as far as we may judge from these experiments ( and they are of a very delicate nature ) , there is no perceptible effect of motion upon radiation . In conclusion the authors desire to say that they are much indebted to Mr. Beckley , who not only invented the apparatus , but assisted at all the experiments , and without whom they could not have been pertformed in a manner so satisfactory . They are also indebted to Mr. Atkinson for his kindness in lending them a large gasometer , and to Mr. Browning and Mr. Lad for exceedingly true aluminium and ebonite disks .
112639
3701662
On the Bones of Birds at Different Periods of Their Growth
299
306
1,866
15
Proceedings of the Royal Society of London
John Davy
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0069
null
proceedings
1,860
1,850
1,800
8
166
4,181
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112639
10.1098/rspl.1866.0069
http://www.jstor.org/stable/112639
null
null
Biology 2
41.59352
Chemistry 1
20.257835
Biology
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III . " On the Bones of Birds at different Periods of their Growth . " By JOHN DAVY , M.D. , & .R.S . , &c. Received October 23 , 1866 . In this paper I beg to submit to the Royal Society the results of some further observations on the bones of birds , and more especially on those bones which in the adult contain air . In offering them , I would wish them to be considered as a continuation of those communicated on a former occasion , and published in the Proceedings of the Society* . In engaging in the inquiry I have had two objects chiefly in view : one to endeavour to determine whether at an early stage the bones , which at maturity contain air , differ essentially from those of birds which are then , and are permanently filled with marrow ; another , to endeavour to ascertain in the instance of the former , the rate at which their early contents are absorbed , or an approximatian to the time that air takes the place of the medulla . The birds of the first kind subjected to observation have been the following : the common fowl , duck , goose , turkey , pheasant , partridge , grouse , rook , common crow , owl , sparrow-hawk , buzzard , blue tit ; of the second kind , the woodcock , blackbird , water-ouzel , marten , swift , greenfinch , titlark , sparrow , stonechat , blackcap , yellow ammer , little sandpipe , canary . I. Of the Common Fowl.-Of this bird I have examined the bones at different ages in a large number of instances . A few are selected as most characteristic : 1 . Of a foetal chick taken from the egg on the fourteenth day of incubation , the bones of the extremities were much advanced , the inferior more than the superior . Their epiphyses were almost gelatinous ; but the shafts were partially ossified , and had already some firmness . In both the humeri and femora , medullary matter was found . It was of a red colour , and under the microscope exhibited the usual character of this tissue . Broken up , in each were seen numerous oil-globules , with which were mixed blood-corpuscles and other corpuscles of a smaller size , some circular , some of an irregular form . Vol. xiv . 337 , 440 , 475 . 2 . A chicken twenty-eight days old , reckoning from the time of hatching , was found dead on the 12th of January ; during the preceding night there had been a severe frost . It weighed 10,275 grs. ; one of its humeri in its moist state weighed 2'5 grs. ; one of its femora 8 grs. In each of them a soft red medullary matter was detected , which , like the preceding , was composed of oil-globules , blood-corpuscles , and smaller colourless corpuscles or cells . The contents of the ulna and clavicular arch were similar , but in the latter the quantity of medullary matter was very minute . 3 . Of a pullet three months old , which had been hatched on the 6th of April , and weighed , when examined , two pounds , the humeri thoroughly ossified , sank in water . From one of them , opened under water , a few airbubbles only escaped , which came from its superior extremity . The canal of the bone , excepting the small portion from which the air proceeded , was full of red marrow of the usual appearance of medullary tissue , and with similar contents . A communication was found to exist by the air-foramen between the cancellated structure towards the head of the bone and the lung , through the adjoining air-sac . 4 . Of another pullet of the same brood , but of more advanced growth , which , though three days younger when examined , weighed two pounds and three-quarters , the humeri sank in water , but in sinking maintained a perpendicular position . One of them laid open was found to contain in its inferior portion , to the extent of '7 inch , marrow ; in its superior , to the extent of 18 inch , air . 5 . Of a pullet three months and eleven days old , which had been hatched on the 28th of May , the humeri floated in water . In one of them , laid open , a small portion of marrow was found in the cancellated structure of its distal extremity ; and in this portion a conspicuous blood-vessel terminated , 6 . Of a cock five months old , which weighed five pounds , the testes large , and abounding in sperm-cells and spermatozoa , the humeri contained only air . II . Of the Partridge.-Of one shot on the 1st of September , which weighed 4136 grs. , the humeri and femora sank in water ; in sinking the distal extremity of the former reached.the bottom first . From one of these , opened under water , a very little air escaped . The lining membrane was very vascular , and the lower one-fourth of the canal was full of blood of a dark colour , contained apparently in varicose vessels . Under the microscope , no oil-globules were distinguishable in the blood , only blood-corpuscles ; nor in any part of the cavity were there found any remains of marrow . 2 . Of another , shot on the same day , which weighed 5226 grs. , the humeri swam in water , the femora sank . Air only was found in the former . On the lining membrane there were two or three delicate vessels containing florid blood . The femora were full of a reddish marrow . 3 . Of another , shot on the 19th of October , which weighed 5-132 grs. , Dthe state of the humeri and femora was very similar to that of the preceding , The humeri contained only air , the femora only marrow ; the lining membrane of the former was finely vascular ; the medullary tissue of the latter abounded in oil-globules and corpuscles suggestive of bloodcorpuscles altered . III . Of the Pheasant.-Of a female shot on the 9th of October , both the humeri and femora swam in water . Both contained air without any marrow . The former were perfectly white , and no vessels were visible in their lining membrane ; the latter were of a reddish hue , and their lining membrane was beautifully vascular , the vessels delicately ramifying , of a bright florid hue , and anastomosing , and this throughout the whole of the circumference . 2 . Of another female , shot on the 17th of October , the humeri contained only air , the femora air with a trace of marrow* . The latter were redder than the former , and their lining membrane was very vascular . IV . Of the Goose.-Of one hatched in the spring , which , when examined on the 26th June , weighed eight pounds , the humeri sank in water . They were full of marrow of a light bright-red colour . The quantity collected from one of them was about 82 grs. It exhibited the usual character of medullary cellular structure , and was rich in oil , which in drying exuded copiously from it ; but it contained comparatively few blood-corpuscles or blood-vessels , of which these corpuscles were the index . 2 . Of another hatched on the 22nd of April , which on the 7th of August weighed nine pounds and a half , a humerus dissected out weighed 561 grs. , was 7'5 inches in length , and its shaft between *4 and *5 inch in width . It sank in water . Its upper third portion was of a darker hue than its inferior two-thirds . The latter was full of a light-red marrow , abounding in oil. . It owed its reddish hue to blood-vessels in the medullary structure . The former , entirely without air , contained a collection of blood-vessels resting on a cancellated structure . These vessels had the appearance of veins , seemed largely varicose , and were full of dark blood , which ( examined whilst warm ) was still fluid . Of the other wing , the humerus was somewhat different the difference was in the superior portion . Although the bone sank in water , a little air was found in this portion , and the blood-vessels in it were less distended , and contained , instead of dark blood , aerated blood of a florid hue . The marrow , which occupied about twothirds of the shaft , terminated abruptly superiorly , and there a pretty large blood-vessel united the two parts the medullary and the varicose portions . 3 . Of another hatched in the spring , examined on the 31st of October , the humeri contained only air . The lining membrane of its cavity was rich in blood-vessels . 4 . Of the humlerus of a goose hatched in the spring , weighing on the 2nd of November nine pounds , the canal was found full of air , with the exception of its inferior one-third ; this contained marrow rich in oil . In one of several portions of it submitted to the microscope , a red vessel was seen containing granules and oil-globules . In one direction it ended abruptly , as if torn ; in the other it was lost , as it were , by diffusion into , or blending with the cells of the medullary tissue . The upper portion of the marrow , it may be remarked , where it came in contact with the air , had , as in some other specimens , a rounded well-defined surface . In this instance no large blood-vessels were found in any part of the bone ; and on the delicate membrane connecting the trabecuiei of the cancellated structure , only a very few delicate vessels of a florid hue were to be seen . 5 . Of a fifth , also hatched in the spring , when examined on the 20th of November , the humeri , like those of the last but one , were found to contain only air . Their lining membrane was very vascular and partially varicose . V. Of the Commoon Duck.-Of a young drake hatched on the 26th of April , which when weighed on the 13th of August was four pounds , the humeri sank in water . They containad a light reddish marrow , and were entirely destitute of air . 2 . Of two ducks of the same brood as the drake , the humeri , examined on the 15th of August , sank in water . Two-thirds of each were filled with marrow ; one-third , the upper portion , with dark blood , seemingly in varicose vessels , which were connected with a light-coloured delicate membrane . 3 . Of a duck , little more then one year old , the humeri contained only air . VI . Of the Red Grouse.-Of one , which on the 12th of August was not fully fledged ( it was shot for examination ) , the humeri contained air , the femora marrow . 2 . Of another more advanced , shot on the 31st of August , weighing a pound and a quarter , the humeri contained air , the femora a little marrow , but more air , the former inferiorly . 3 . Of a third , shot on the 28th of August , which weighed 8770 grs. , the humeri were hollow , the femora partially so , a little reddish marrow 'only remaining , and this in their inferior extremity . 4 . Of one shot on the 27th of August , which weighed 11,856 grs. , and which , judging from its plumage , was probably a spring bird , both the femora and humeri swam in water and were free from any trace of marrow . The liining membrane of the cavities of the femora was beautifully vascular , the vessels of a florid hue from the well-a6rated blood which they contained . The lining membrane of the humeri was similarly vascular , but in a less strongly marked manner . VII . Of the Rook.-Of a youngone not quite capable of flight , shot on the 11lth of May , and which th enu weighled 6132 grs. , the humeri sank in water ; they contained no air , but a soft marrow , of a blood-red colour . The bones were very vascular , and were easily cut . 2 . Of another , shot on the 22nd of June , when capable of flight , though the quill-feathers of its wings were only partially hollow , its weight 5113 grs. , the humeri sank in water in a perpendicular position . Of one which was examined , its inferior two-thirds were found full of a reddish marrow , its superior one-third of air . The proportion of oil seemed greatest in the distal part of the marrow . The bones were less vascula than those of the preceding , and pf greater firmness . 3 . Of a third , shot on the 23rd of June , then weighing 4982 grs. , which , judging from the state of its feathers , its bursa Fabricii , ovary , and oviduct , had been hatched in the spring , the humneri were full of air without a vestige of marrow * . VIII . Common C'ow.-Of one shot on the 1st of June , then weighing 5402 grs. , its quill-feathers not fully formed , the humeri sank in water , and contained only marrow . 2 . Of another shot on the 21st of June , weighing 6533 grs. , capable of flight , the humeri contained air . The lining membrane was very vascular . IX . Of the Tawny Owl.-Of a young one , examined on the 21st of June , then weighing 4796 grs. , its quill-feathers not fully formed , the humeri contained a very red marrow , and were entirely destitute of air . 2 . Of one of uncertain but mature age , judging from its general appearance , and which weighed on the 8th of April 5776 grs. , the humeri were full of air . There was also air in the scapular arch , and partially in the furcula , its proximate portion . X. Of the Sparrow-hawk.-Of a young one , which on the 31st of July weighed 3686 grs. , its sternumn then only partially ossified , still flexible , the humeri were for the most part hollow ; the little marrow they contained was confined to their distal portion . The same remark was applicable to the scapular arch . The femora contained even less marrow than the humeri ; they were very nearly full of air . XI . Of the Buzzard.-Of a young one taken from its nest on the 10th of June , when supposed to be about a fortnight old , then weighing 5293 grs. , the qiill-feathers of wings only sprouting , the bones generally were very vascular ; the humeri and femora sank in water . Their ossification was much advanced , but the sternum was still cartilaginous . After drying , all the bones floated in water . The humeri and femora , now laid open , were found to contain a red matter lining but not filling the cavities , suggestive of its having been , in its moist state , a fluid or a semifluid . In this , its dried state , it was of a firm consistence . After soaking in water and trituration , it formed an emulsion , which , as seen under the microscope , was found to contain oil-globules and particles of different kinds . Digested and heated in alcohol , it was partially dissolved , the solution becoming turbid on cooling . Evaporated , and as seen under the microscope , the residue , proportionally small , seemed to consist chiefly of fatty and oily matter ( stearine and olein ? ) , with some needle crystals . XII . Of the Blue Tit.---Of a young one taken from the nest on the 31st of May ; then weighing 28-5 grs. , quite naked , except a few delicate fibre-like feathers on the head , some yolk still remaining in the abdominal cavity , the humeri were very small and pale , so small that no attempt was made to examine them , except by crushing . Comminuted with a few drops of solution of salt , and subjected to the microscope , there were seen mixed with the fragments of cartilage , blood-corpuscles and oil-like globules . 2 . Of a young one , nearly fully fledged , which on the 3rd of August weighed 142 grs. , the humeri sank in water , maintaining a perpendicular position . They were completely formed and well ossified . Excepting towards their inferior extremity they were white , there to a small extent they were red . The white portion , at least nine-tenths of the entire length , contained air ; the red , not exceeding one-tenth , marrow which , as seen under the microscope , had all the character of medullary tissue and abounded in oil . 3 . Of a third , shot in the same place as the preceding , and probably of the same brood , which on the 18th of August weighed 179'5 grs. , the humeri floated in water , and were entirely full of air . The feathers of the abdomen were not fully formed , and the bursa Fabricii was much smaller than that of the preceding . From these results , may not the following conclusions be drawln ? First , that at an early stage , and up to a certain period of growth , marrow exists in the bones specified , of all the birds first named ; and that about the time of hatching the medullary tissue abounds less in oil or fatty matter than at a later , the proportion varying in different instances ; least probably in birds of prey , such as the buzzard and owl ; most in birds , the food of which is mostly vegetable , such as the goose . Secondly , that the substitution of air for marrow in those bones which are eventually hollow , varies as to time in different species ; is earlier in the rook , the crow , the grouse , the tit , than in the common fowl , duck , and goose , especially the latter ; the exchange of one for the other having probably some relation to the time of taking wing and the use of the parts ; and , in accordance , the humeri , except in the instance of the sparrow-hawk , seemed to have the marrow absorbed somewhat-earlier than the femora . It may be conjectured that , like the residual yolk in the young bird , the marrow in the bones in question may serve in part as food , nourishing in the act of its removal . Relative to the structure of the hollow bones , I have but a few words to offer . , In the humeri there is a peculiarity which may be deserving of mention . Towards the head of the bone , near the pneumatic foramen , the cancellated structure , connected more or less by a delicate membrane , performs the part of a valve , as indicated by its permitting a free access of air in one direction , but preventing in the other , its exit . This is clearly shown by the use of the blowpipe , and in no instance have I found an exception . In the humerus of the common fowl , in three instances ( a section of the bone having been made ) the air ias been found to enter from the pneumatic foramen by a small bony canal contiguous to the side of the bone , in length about '6 inch , in diameter about '06 inch * . It is said that the trabeculae , or minute columnue in the cancellated structure of the hollow bones , are also hollow . In some of those of the humeri of the adult buzzard I have found a canal , but not in others ; these were solid . Nor have I found them otherwise than solid in the humerus of the common fowl , goose , and turkey . As to the bones of those birds of the second kind , in which the marrow is persistent through life , I may briefly remark that in them , as in the former , at an early period the marrow seems to be comparatively poor in oily matter ; and that the earlier , the nearer the embryo state , the less is its degree of consistence , the nearer it is to a liquid , and the larger is the proportion of blood-corpuscles and of albuminous matter , and the smaller the proportion of the adipose . When mature of growth , the bones of these birds appear to be richer in oily matter than those of the former permanently without air . Thus the tibia of the one kind in the dried state invariably sinks in water , whilst that of the first kind only partially sinks ; the marrow in drying in the latter , from containing less oil , contracting more , and allowing of the entrance of air . In the radius and ulna the difference is less strongly marked ; these bones in their dried state commonly sinking in water , even when belonging to birds of the first kind . As regards the quality of marrow in the bones of different birds , the trials I have made have been very limited . I am disposed to infer from them that , besides differing , as in many instances it does in colour , it may differ also in composition , in the proportion of adipose matter and its kind , and in the proportion of albuminous matter ; in some , as in the bones of the goose , oil most abounding ; in others , as in those of the rook and buzzard , albuminous matter and fat of the stearine kind . Even in the bones of birds of the second kind , such as their long bones , there is a difference in this respect ; of these , all that I have examined sink in water , with the exception of the femora , which only partially sink , the marrow in them being less rich in adipose matter , and consequently in drying contracting more , and , as before remarked , admitting more air . As to the marked difference of birds of the two kinds in relation to the condition of their bones , the rationale is not very obvious . Perhaps an approximation to the truth , or to the probable , may be made by comparing the bones of birds of the two kinds , which are possessed of similar powers , the swift , for instance , and the buzzard , rivals in swiftness of -fight and enduring power of wing . How different are their humeri ! of the former , very short , strong , and compact , provided with firm and large processes for the attachment of muscles ; in the latter , long , hollow , ald light , and comparatively brittle , yet sufficiently firm to bear without fracture the muscles which act on them . Here , have we not after a manner a kind of substitution of qualities ? great strength and extended surface in small space in the one , for lightness with greater length of leverage in the other . Further , the one kind of bone , that which contains marrow , being less brittle than that which contains air , and more yielding , may be less liable to fracture ; a quality which , in the bird , before the ossification is complete , may be of essential service ; so that , teleologically considered , it may perhaps serve to account for the bones which are eventtually hollow having primarily marrow in place of air .
112640
3701662
On Poisson's Solution of the Accurate Equations Applicable to the Transmission of Sound through a Cylindrical Tube; and on the General Solution of Partial Differential Equations. [Abstract]
306
310
1,866
15
Proceedings of the Royal Society of London
R. Moon
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
5
58
1,656
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112640
null
http://www.jstor.org/stable/112640
null
null
Formulae
63.95638
Fluid Dynamics
27.762953
Mathematics
[ 41.16151428222656, -33.901607513427734 ]
I. On Poisson 's Solution of the Accurate Equations applicable to the Trans-mission of Sound through a Cylindrical Tube ; and on the General Solution of Partial Differential Equations . " By R. MOON , M.A. , late Fellow of Queen 's College , Cambridge . Commnunicated by Prof. J. J. S-YLVESTER . Received INovember 14 , 1866 . ( Abstract . ) The pair of equations v=(Pf{ ( v+a)t which constitute Poisson 's solution of tih accuralte equations applying to the transmlission of sound through a cylindrical tube derived by La Grange 's method , have long attracted the attention of mathematicians . For La Grange 's equations we may substitute the following , viz. cv a2 dp a dt JD dx dv+D dp=o dx p2 dt The first of these is obtained from the equation of the Encyc . Met . ( Art . " Sound " ) ; by putting v for die and D for die dt p dx The second results from a similar substitution in the analytical condition , d[d ? q d/ die Poisson 's solution has always been regarded as imperfect , and may easily be shown to be so . I was some time ago struck by finding that the above equations , while they yielded with facility the result of Poisson , notwithstanding their simplicity , baffled every effort to extract from them one more consonant to the general exigencies of the problem . I had at this time arrived at the conclusion that the law of pressure assumed in the received theory of Fluid Motion could not be generally true , and in a Paper* communicated to the Royal Society , had pointed out that , in a certain case of motion , the assumption of the truth of that law led to a contradiction ; while in another case of motion the expression for the pressure given by the received theory was palpably erroneous . It occurred to me , therefore , that the defective law of pressure of the received theory accounted for the defective solution which alone was obtainable from the equations of motion derived from it . If the law of pressure of the received theory was not always true , if it held only when certain conditions were satisfied , those conditions would obviously have the effect of dismissing from the complete solution of the problem obtained on a perfect theory at least one of the two arbitrary functions which it must necessarily involve . With a view to establishing this point , assume the solution of the equations of motion to be contained in the pair of equations , F(xytpv ) = { f( ytpv ) } , . ( B ) F(tytop)4'={/ ( Z3)}* Jyv ee If these equations satisfy the equations ( A ) , the latter will equally be satisfied by the pair of equations , F(xytpv ) =v , F(wy tpv ) ={f(xy tpv ) } . But it is shown in my Paper that these latter can only satisfy the equations ( A ) on the supposition that F is of the form F==F(v alog , p ) . Moreover , since we have in equations ( B ) the function F equal to an X On the Trtue Theory of Pressure as applied to Elastie Fluids in Motion . 2c2 arbitrary function of f , conversely we must have f equal to an arbitrary function of 1 . I-ence , in exactly the same way in which it is proved that F must have the above form , we may equally prove that f , F , f must severally have the same form . It clearly results , therefore , from the above assumed solution ( B ) , that the equations ( A ) are insoluble , except on the assumption that the velocity may be expressed in terms of the density alone ; i. e. that we may assume v =f( ) . But substituting this value of v in equations ( A ) , the latter become dp a dp ( p ) Sz2 + D , / dt D 4 , '_ f ( p p+ D dt)_o dx P dt-whence we get ) ' . 2=p dpf_ ap2 1dp . / ( ^ p ' ~di\ dr\ and eventually , D being the value of p when v=O , +h v_ loc. -D P ? =- . ? a t } which is the most general solution of which the equations of motion are susceptible ; and which , making allowance for the difference of the ordinates employed in the two cases , y referring to the particle when in motion , and x to its position of rest , is identical with that of Poisson . The failure of mathematicians to derive from the equations of motion of the received theory a solution containing two arbitrary functions has hitherto , I apprehend , been universally attributed to difficulties of integration . So far is this view from being well founded , however , that in a postscript to my Paper it is shown that , assuming the pressure to follow any law whatever , a solution of the equations of motion can be obtained containing two arbitrary functions ; a result , however , which requires that the expression for the pressure shall satisfy certain conditions , which conditions are violated when the pressure is assumed to vary with the density alone . Whatever be the law of pressure , it must always be capable of being expressed in terms of x and t. Moreover , the velocity and density are in like manner severally capable of being expressed in terms of x and t ; whence it follows that we may always express x in terms of p and v , and equally that we can express t in terms of p and v ; so that , whatever be the law of pressure , we may assume it to be a function of p and v. Hence , assuming dp_dp , +dp dv , _p+ dv dx dp dax dv dx dx dx ' where R and V are functions of p and v only , we I have for our equations of motion the following , viz. dv R dp V dv ? Ct +D+b D ' & +dv D dp dx T2 dt of which the following pair of equations constitute the solution , viz. f2(p , v)=~ { V2 V2 -4Rp2 } Ae , ( p , ? ) 2V ' ' wheref , ( p , v ) , =const . , and f , ( p , v)=const . are the respective integrals of the ordinary differential equations , dv-_ W +4R dpdv- ? p 2 --dp = O , 2p which involve the variables v and p only . But this result is depellent on the fact of the following conditions being satisfied , viz. , that we have 3dp dv where K , =VVV2+411p2 , K , =VV4Rp2 , which conditions cannot be satisfied if the law of pressure depends upon the density only ( in which case =0 and R contains p only ) , as may easily be shown . With regard to the theory of Partial Differential Equations , I conceive that the methods indicated in the Paper will serve to elicit every solution of a partial differential equation of the second order and first degree , save one , viz. , an integral solution consisting of a simple relation between the variables x , y , z , free from arbitrary functions , and which is not derivable from a solution containing arbitrary fimctions , by assigning particular values to the latter . If the equation O=Rd2 + dz +TV d ; ? dxdy die have a first integral consisting of the pair of equations F(xyzpq)=of{f(xy-pq ) } , F(s yq ) =44 ( ytzIq ) , or consisting of the pair of equations F(xyzpq ) =0 , P( yzp= ) = { f(x yp , q ) } , or of the single equation F(yzp q ) = < / f(xJyzpq ) } , or of the single equation F(xyzp ) =0 ) then in every one of these cases we must have 0==R . F'(q)-S.(q ) . F'().(p ) + T. '(p ) , O-R . F'(x ) . F'(q3 T. F'(29 ) . F'(q ) + R. F'(q).2 + T. '(p ) ? }F'(z ) +Y . F'(p).F'(q ) . It is also shown with more or less of generality , and it is capable of being shown generally , that if the given equation admit of a complete integral solution containing two arbitrary functions , it will necessarily have two first integrals , each of which will be of the form F(xypq ) = { f(xyz)q } . It might have been added , that if the general equation of the second order and second degree be written O= Pr2 . ? P , . *2 2 ' t2 +P sP P. et + . st +Pyr+P.S . 8+Pe +P ; and it is satisfied by the equation F(yZ-pq ) ( { f(xypq ) } then F and f must severally satisfy all three of the following equations , viz. F'(p ) ' ( ) =0 , F'(x ) qr':(O , z , , , Y'p ) = 0 , F'( ) + F ' , ( )~ -m '( ) =0 , where 0-P~ , . 14--_P . 13 ( Ps2 +Pg.)1--Ps . lP , 0P nm2P , ,p 4-IP~2n2-P-P nP , 0-(2Pr--P2s . l+P./ 12)M +(2Pe 12-Ps . tPr)n -(P2_ Ps I+Pr ) . T ' he functions f/ , m , must satisfy the sa-ne conditions , except in the second of the above cases .
112641
3701662
Abstract of the Results of the Comparisons of the Standards of Length of England, France, Belgium, Prussia, Russia, India, Australia, Made at the Ordnance Survey Office, Southampton. [Abstract]
311
314
1,866
15
Proceedings of the Royal Society of London
A. R. Clarke|Henry James
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
4
70
1,563
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112641
null
http://www.jstor.org/stable/112641
null
108,974
Biography
50.872793
Measurement
27.089506
Biography
[ 55.923465728759766, 20.63838768005371 ]
II . " Abstract of the Results of the Comparisons of the Standards of Length of England , France , Belgium , Prussia , Russia , India , Australia , made at the Ordnance Survey Office , Southampton . " By Captain A. R. CLARKE , R.E. , F.R.S. , &c. , under the Direction of Colonel Sir HENRY JAMES , R.E. , F.R.S. , &c. , Director of the Ordnance Survey . Received November 15 , 1866 . ( Abstract . ) In the preface to this paper , Sir Henry James gives an account of the circumstances under which the work was undertaken , as follows . ( A Table of results is appended , p. 313 . ) The principal triangulation of the United Kingdom was finished in 1851 ; and the triangulations of France , Belgium , Prussia , and Russia were so far advanced in 1860 , that , if connected , we should have a continuous triangulation from the Island of Yalentia on the south-west extremity of Ireland , in north latitude 51§ 55 ' 20 " , and longitude 10§ 20 ' 40 " west of Greenwich , to Orsk on the River Ural in Russia . It was therefore possible to measure the length of an arc of parallel in latitude 52 ? of about 75 ? , and to determine , by the assistance of the electric telegraph , the exact difference of longitude between the extremities of this arc , and thus obtain a crucial test of the accuracy of the figure and dimensions of the earth , as derived from the measurement of arcs of meridian , or the data for modifying the results previously arrived at . The Russian Government , therefore , at the instance of M. Otto Struve , Imperial Astronomer of Russia , invited ( in 1860 ) the cooperation of the Governments of Prussia , Belgium , France , and England , to effect this most important object , and to their great honour they all consented , and granted the necessary funds for the execution of the work . The portion of the work which was assigned to me , was the connexion of the triangulation of England with that of France and Belgium , and I published the results of this operation in 1862 * . But this work has been done in duplicate ; for when application was made to the French Government to permit the necessary observations to be made in France , they not only consented to allow this , but at the same time volunteered to join in the labour and expense of the work itself . It would obviously have been wrong to mix up observations made with different kinds of instruments and on different principles , and therefore it was agreed that the work should , in fact , be made in duplicate , both the French and English geometricians using exactly the same stations . The results obtained by the French geometricians is published in the Supplement to vol. ix . of the ' Mimorial du Depot G6neral de la Guerre , ' 1865 , and the agreement with the results obtained by the English is truly surprising . But however accurately the trigonometrical observations might be performed , it is obvious that , without a knowledge of the exact relative lepngths of the standards used as the units of measure in the triangulation of the several countries , it would be impossible accurately to express the length of the arc of parallel in terms of any one of the standards . It was therefore necessary that a comparison of the standards of length should be made , and as we had a building and apparatus expressly erected for the purpose of comparing standards at this Office , the English Government , on my recommendation , invited the Governments of the several countries named to send their standards here , and we have had the following compared with the greatest accuracy:1 . 1Russian standard , double toise , P. 2 . Prussian standard toise . 3 . Belgium standard toise . 4 . Platinum metre of the Royal Society , compared with the standard metre of France by 1M . Arago . 5 . English standard yards , A , B , C , 29 , 47 , 51 , 55 , 58 . 6 . Ordnance Survey 10-foot standard bar . 7 . Indian 10-foot standard bars , new and old . 8 . Australian 10-foot standard bar . 9 . In addition to the above , the 10-foot standard bar of the Cape of Good Hope was compared heie in 1844 . We have invited the Governments of Austria , Spain , and the United States of America , also to send their standards . We have been promised that of Austria , and , but for the unfortunate war in which she has been lately engaged , we should have received it before this . I have entrusted the execution of the work of comparison and the drawing up of the results to Captain Alexander R. Clarke of the Royal Engineers , who designed the apparatus used . The numerous comparisons to be made entailed a great amount of labour upon him and his assistants , Quartermaster Steel and Corporal Compton , of the Royal Engineers . Before the connexion of the triangulation of the several countries into one great network of triangles , extending across the entire breadth of Europe , and before the discovery of the electric telegraph and its extension from Valentia to the Ural Mountains , it was not possible to execute so vast an undertaking as that which is now in progress . It is , in fact , a work which could not possibly have been executed at any earlier period in the history of the world . The exact determination of the figure and dimensions of the earth has been the great aim of astronomers for upwards of two thousand years , and it is fortunate that we live in a time when men are so enlightened as to combine their labours to effect an ob t-I Expressed in Expressed in Expressed in Terms of the Expressed in lines of the Millimetres. . Standard Yard . inches . Toise . * 1~~~ Measures-- . Millimetre= o. Inch= . Line-=. . ; tit . The Yard ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... . 100000000 36-000000 405-34622 914-39180 Copy No. 55 of the Yard at its Standard Temperature of 62-00 F ... ... ... ... . 0-99999960 35-999986 ! 40534606 914-39143 Ordnance Standard Foot , , , , , , 62-00 ... ... ... . . 033333284 11-999982 135-11521 304'79681 . Indian Standard Foot , , , , 6200 ... ... ... ... ... 033333611 12-000100 135-11653 304'79980 Ordnance 10-foot Bar . , , , , , 62-00 ... ... ... ... . . 3-33333717 120-000138 1351-15563 3047'97616 Ordnance 10-foot Bar 01 , , , , 6200 ... ... ... ... . . 3-33335432 120-000755 1351-16259 3047-99184 9 Indian 10-foot Bar Is , , , , , , 6200 ... ... ... . 333340138 120-002450 1351-18166 3048-03488 Indian 10-foot Bar 1B , , , , , , 62-00 ... ... ... ... . . 3-33353284 120-007182 1351-23495 3048-15508 Indian 10-foot Bar I , , , , 62-00 ... ... ... ... ... 333331457 119-999324 1351-14647 3047*95550 Australian Standard 04 , , , , 6200 ... ... ... ... ... 333330427 119-998954 1351'14230 3047-94608 . ' Australian Standard 01 , , , , 62-00 ... ... ... ... . . 333333747 120-000149 1351-15576 3047-97644 Ordnance Toise , , , , , 6125 ... ... ... ... . 2-13166458 76-739925 864-06219 1949-17660 Ordnance Metre , , , , , 6125 ... ... ... ... . . 1-09374800 39-374928 443-34662 1000-11420 Royal Society 's Metre a traits , , , 3200 ... ... ... ... ... 109360478 39-369772 443-28857 999-98324 Prussian Toise No. 10 , , , , , , 6125 ... ... ... ... ... 2-13150911 76-734328 863-99917 1949-03444 Belgian Toise No. 1 , , , , , 61-25 ... ... ... ... ... 2-13150851 76-734306 863-99893 1949-03390 Russian Double Toise P , , , , 61-25 ... ... ... ... ... 4-26300798 153-468287 1727-99419 3898'05952 The Toise ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... . . 2-13351116 76-734402 864-00000 1949-03632 The Toise ... . . , ,. . 2'13151116 76'734402 864'00000 1949'03632 The Metre ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... . . 09362311 39-370432 44329600 100000000 C3 ject desired by all , and at the first moment when it was possible to execute it . A full detailed account of the 'Comparisons of the Standards of Length , ' with numerous plates , has just been published , and may be obtained from the agents for the sale of the publications of the Ordnance Survey .
112642
3701662
On the Formation of 'Cells' in Animal Bodies. [Abstract]
314
318
1,866
15
Proceedings of the Royal Society of London
E. Montgomery
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
5
83
1,973
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112642
null
http://www.jstor.org/stable/112642
null
null
Biology 3
70.054112
Chemistry 1
12.864731
Biology
[ -65.89311218261719, 12.68311595916748 ]
I. " On the Formation of 'Cells ' in Animal Bodies . " By E. MONTGOMERY , M.D. Communicated by J. SIMON , Esq. Received November 8 , 1866 . ( Abstract . ) I. Observations , So called organic " cells , " chiefly those of various cancerous tumours , were seen , on the addition of water , to expand to several times their original size , and at last to vanish altogether into the surrounding medium . The " nucleus " did not always participate in this change , but at times remained unaltered , whilst the outer constituents of the " cell " were undergoing this process of expansion . This curious phenomenon of extreme dilatatioi is intelligible only on the sulpposition that the spherical bodies in question are in reality globules of a uniformly viscid material , which by imbibition swells out till at last its viscosity is overcome by the incrasing liquefaction . In embryonic tissues and in various tliours , single " nuclei " were seen , each surrounded by a shred of granular matter . On the addition of water there would bulge from one of the margins of the granular mass a segment of a clear globule , which continued growing until it had become a full sphere , which ultimately detached itself , and was carried away by the currents . At other times no such separate globule would be emitted , but the entire granular shred would itself gradually assume the spherical shape , ultimately encompassing the " nucleus , " and constituting with the same the most perfect typical " ( cell . " Not only single " nuclei " were found , each surrounded by a shred , but also clusters of two , four , and more were seen similarly enclosed by a proportionately large granular mass . Under these circumstances it sometimes occurred that , on the addition of water , the whole granular mass of such a cluster became transformed into a large sphere , containing two , four or more " nuclei . " The resulting body was to all appearance identical with shapes well known under the name of " mother-cells . " In all these cases the granular shred must have partly consisted of a viscid material , which , on imbibition , naturally assumed the spherical shape . Primary globules were surrounded by a secondary globule , and thus the typical " cell " was completed under the observer 's eye . In some instances the globules resulting from the transformation of the granular mass were at first bright and transparent , the granules having completely disappeared . They , however , gradually reformed , showing at first molecular motion , then crowding more and more , till at last the whole mass seemed to undergo coagulation . Alternate liquefaction and coagulation of the same material was found to play an important part in the development of " cells . " Masses of certain viscid materials do not , on imbibition , expand uniformly throughout their entire bulk , but globules of a definite size are emitted , as many as the mass will yield . The crystalline lens of many young animals affords , when treated with water , a beautiful illustration of this fact . Its homogeneous material is transformed , under the influence of imbibition , into a vast number of globules of nearly equal size . Hyaline embryonic tissues display , under similar conditions , the same phenomenon . Certain inferences lead one to suspect that this size-limiting property is due to the crystallizing propensity of some ingredient of these viscid substances . Blood-corpuscles , human blood corpuscles at least , are evidently tiny lumps of a uniformly viscid material . When broken up into fragments , each fragment assumes the spherical shape . On slow imbibition , they often emit a clear sphere , or a segment of one . In various specimens of foetal blood , each blood-corpuscle was seen to emit as many as two and even three equally sized globules , the original corpuscle being at last no more distinguishable from its descendants . This is sufficient proof of the uniformly viscous nature of the blood-corpuscles . In many cancers the most recently formed part consists of mere fibres . These after a time become " nucleated . " The " niuclei " are at first very elongated , this being due to the lateral pressure of the still fibrous texture . But as the mass gradually softens , the ovals expand more and more into spheres , forming the primary globules , round which , as has already been shown , a secondary globule is often seen to shape itself . Chemical differentiation transforms first one portion of the fibrous mass into viscid inaterial . This at once strives , by imbibition , to assume the globular shape . The remaining portion may or may not ultimately undergo similar transformation . Inflamed serous membranes become often densely " nucleated . " In the deeper layers , the " nuclei " are very elongated . At the surface they are perfectly globular , and are detached as minute opaque balls . These balls are the granulationor the pus-corpuscles . On imbibition , one portion of their soft material swells out , encompassing the rest , which , when forming a single uniform globule , goes under the name of granulation-corpuscle ; when , on the other hand , broken up into several granules , constitutes the famous pus- " cell . " This is an example of a second mode of " cell " -formation . Here the secondary globule is shaped from a portion of the primary mass . In some instances these " nuclei " or balls will , when still enclosed within the surrounding texture , undergo the above-mentioned change on imbibition , and thus whole rows of granulation or pus-corpuscles are seen to form . This second mode of " cell " -formation is still more strikingly manifested in epithelial textures . In the mucous membrane of the nose , for instance , the faint oval " nuclei " of the large scales become during disintegration more and more distinct and globular . The surrounding material of the scale gradually liquefies , and the minute balls , thus liberated , expand by imbibition into mucusor pus-corpuscles . It often succeeds to make them form in all perfection whilst they are still contained within the scale . In abscesses of the skin the pus-corpuscles are formed in exactly the same manner . They can often be watched , fully shaped , still enclosed within the scale . Here , it would seem , are " cells , " not the result of life , but rather of death . The multiple " nuclei " of pus-corpuscles are not the result of overfecundity , but are simply due to the disintegration of the non-imbibing portion of those oval or spherical clear-cut bodies , which are themselves so well known under the name of " nuclei . " The disintegration of this non-imbibing portion can be traced through all possible stages , down to the cluster of most irregularly shaped granules ( which , notwithstanding , have been looked upon as the result of fissiparous division ) , and has been made to represent the crowning feature of the cell theory . The same minute balls found swimming in the serum of a blister were seen , when treated with water , to disclose single bright clear cut " nuclei ; " when treated with acetic acid , to reveal the most typical multiple nuclei of pus-cells . II.--Experimental Verification . In all the above-cited observations the existence of a viscid , imbibing material was proved with almost conclusive evidence , -a viscid material which is capable of forming globules of a definite size , and which in the living organism actually forms such globules ; shapes , the nature of which has been hitherto mistaken . After a long search , the substance known under the name of myeline was found to be the desired material . When to myeline in its dry amorphous state water is added , slender tubes are seen to shoot forth from all free margins . These are sometimes wonderfully like nerve-tubes in appearance . They are most flexible and plastic . From this curious tendency of shooting forth in a rectilinear direction it was inferred that a crystallizing force must be at work . To counteract this tendency , and to oblige the substance to crystallize into globules , it was intimately mixed with white of egg . The result was most perfect . Instead of tubes , splendid clear globules , layer after layer , were formed , resembling closely those of the crystalline lens formed under similar conditions . Here was actually found a viscid substance which , on imbibition , formed globules of a definite size . The remaining task was comparatively an easy one . By mixing the myeline with blood-serum , globules were obtained showing the most lively molecular motion . When the serum somewhat : preponderated , the whole globules seemed , after a while , to undergo coagulation , and appeared often as beautifully and finely granulated as any real " cell . " When this mixture of myeline and serum was spread very thinly over the glass slide , there often started into existence , on the addition of water , small primary globules , round which an irregular mass of granular material became gradually detached from the glass slide . It at last shaped itself into a secondary globule , enclosing the primary one , and constituting with it , down to the minutest details , the most perfect typical " cell . " In many instances the nucleolus did not fail , and the narrow white margin , so often mistaken for a cell-wall , was always present . Beautiful " mothercells " were formed in the same manner . The next endeavour was to form " cells " according to the second mode . If the amorphous myeline be very thinly spread on the glass slide , instead of tubes there will form bodies looking like rings . They are actually double globules , the inner globule being more transparent than the outer . They correspond to the inner and outer substance of the abovementioned tubes . When these are left to dry , and then again acted upon with water , one portion will swell out into a clear globule , enclosing the rest as " nucleus . " These " nuclei " are either large and single , like those of granulation corpuscles , or they are multiple , exactly like those of puscells . Whole layers of perfect pus-corpuscles are thus formed . But , of course , more complicated shapes o'cur as well . Among these , for instance , many such pus-cell-like bodies enclosed within one large sphere . If , instead of water , serum be added to the thinly-spread myeline , biconcave disks will form , only generally much larger than blood-corpuscles . " Cells " being thus merely the physical result of chemical changes , they can no longer afford a last retreat to those specific forces called vital . Physiology must aim at being something more than the study of the functions of a variety of ultimate organic units . And pathology will gain new hope in considering that it is not really condemned to be the interpreter of the many abnormities to which the mysterious life of myriads of microscopical individuals seelme to be liable .
112643
3701662
Preliminary Notice of Results of Pendulum Experiments Made in India
318
319
1,866
15
Proceedings of the Royal Society of London
Lieut.-Col.Walker
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0073
null
proceedings
1,860
1,850
1,800
2
36
495
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112643
10.1098/rspl.1866.0073
http://www.jstor.org/stable/112643
null
null
Meteorology
43.868793
Biography
16.720837
Meteorology
[ 35.94534683227539, 6.682581424713135 ]
II . " IPreliminary Notice of Results of Pendulum Experiments made in India . " By Lieut.-Col.\WALKEni , F.R.S. : in a Letter to the President . Received September 21 , 1866 . I have the pleasure to enclose a provisional abstract of the results of Capt. Basevi 's observations with his pendulums during the past field season . Though provisional , it will probably be found to agree very closely with the final results , which will be deduced as soon as the corrections for buoyancy , temperature , &c. are finally known . Already these experiments are beginning to throw light on the subject of I-imalayan attraction ; for the observations clearly show that the force of gravity is less than it shouldc be theoretically at the stations in the vicinity of the Himnalayas , and that the difference between theory and practice diminishes the further the station is removed from the Himalayas . This is a remarkable confirmation of Airy 's opinion , that the strata of the earth below mountains are less dense than the strata below plains and the bed of the sea . Combining these observations with those that were used by Mr. Bailey ( including , I believe , all your own ) , the value of the ellipticity will be diminished from -g to 2-j ( approx. ) , and will therefore tend more closely to assimilate with Capt. Clarke 's value , x4 . * The pelndulum result is 28-4-E . S. [ Dee . 204 318 Field Season 1865-66 . Reduced to Mean Temperature 69 ? '69 . Observed vibraReduction to alue of ellipHeightt tions per diem i sia Compted Vibrations ticity , each above vacyto , reduced to using in ters of Usia.h Name of Station . Latitude . Mean mean sea-level . Means . ellticity . copar with SeaLevel. . Leel. . | Clarke , Bailey , ' No. 4 . iNo . 18 . 1 Clarke . Bailey . Usira . ew . 294285-3 . , , feet . + ' ? Dehra * ... ... ... ... 30 20( 0 2289 86076-426 85975-631 86026-029 11-192 10-970 86031-288 86031-0W6 -1 16 Nojli ... ... j 129 53 28 881 86076.843 85975-724 86026-284 9-681 9-490 86029777 86029-58 Kajliana ... ... 86049-777 860291586 1L Kaliana 9 ... | 29 30 55 826 86075992 85975-4(i6 86025-729 8-408 8-241 86028504 86028337 |1_9 Dateri ... ... | ' 28 44 5 719 86075-156 85974-782 04 86024609 595 . 1 860289 0777 8602 -7 l1 Usira ... .j H| 26 57 7 812 86070-520 85969-672 86020-096 ... ... ... ... ... ... ... ... ... ... ... ... ... ... Kew ... ... ... ... ... 51 28 10( ? ) ... ... 86165483 86064-410 86114-947 91-682 89-871 86111'778 86109-967 f , ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * Dehra is situated in a valley between the Hinalayas and the Siwaliks . *-E9 00 0x O ' : < o5 ^ ? T%1
112644
3701662
On the Appendicular Skeleton of the Primates. [Abstract]
320
321
1,866
15
Proceedings of the Royal Society of London
St. George Mivart
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
2
20
529
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112644
null
http://www.jstor.org/stable/112644
null
108,977
Anatomy 2
58.886848
Biography
16.447373
Anatomy
[ -56.25486755371094, 44.84518814086914 ]
" On the Appendicular Skeleton of the Primates . " By ST . GEOaGE MIVART , F.Z.S. , Lecturer on Comparative Anatomy at St. Mary 's Hospital . Communicated by Prof. HUXLEY..Received November 22 , 1866 . ( Abstract . ) The author began by mentioning the principal variations found in the order Primates , as to the absolute and relative length of the pectoral limb with and without the manus ; and then taking each bone separately , described the modifications undergone by each in all the genera of the order* ; as also the relative size of the segments and bones of the limb compared to each other and to the spine . The pelvic limb was then similarly treated of , and , in addition , its segments and bones were compared with the homotypal segments and bones of the pectoral limb . The author after this reconsidered the question as to the use of the terms " hand " and " foot , " and the applicability of the term " Quadrumanous " to Apes and Lemuroids . He controverted the position lately assumed by Dr. Lucaet , that both anatomically and physiologically the pes of apes is more like the human hand than the human foot . At the same time he recommended the use of unambiguous homological terms , such as " manus " and " pes " ( already adopted by some ) instead of " hand " and " foot , " in all treatises on comparative anatomy . Tables of the dimensions and proportions of the limbs , their segments , and bones were then given , exhibiting the variations presented in these respects throughout the whole series of genera . The author then considered the more peculiar forms of the order , beginning with Man . The principal resemblances and differences in form , size , and proportion between the human appendicular skeleton and that of other primates were given in detail , followed by a list of those points in which man differs , as to the bony structure of his limbs , from all other primates . The limb-skeletons of the Orang , Marmoset , Indri , Slender Lemur , Tarsier , and Aye-aye were then similarly reviewed , and lists given of the absolute peculiarities found in each . The conclusion arrived at from these comparisons was , that Man differs less from the higher Apes than do certain primates below him from each Except certain Lemuroids , of which no specimens exist in this country . t Abhandlungen von der Senckenbergischen Naturforschenden Gesellschaft . Frankfort , 1865 , vol. . p. 275 . other ; and that he , thus judged , evidently takes his place amongst the members of the suborder Anthropoidea . A list of the principal osteological variations presented by the several groups and genera of the order , before unmentioned , was then given ; and the author concluded by stating what he believed to be the degrees of affinity existing between the various forms , as far as could be ascertained from the consideration of the appendicular skeleton exclusively .
112645
3701662
Actinometrical Observations among the Alps, with the Description of a New Actinometer
321
330
1,866
15
Proceedings of the Royal Society of London
George C. Hodgkinson
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0075
null
proceedings
1,860
1,850
1,800
10
168
4,357
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112645
10.1098/rspl.1866.0075
http://www.jstor.org/stable/112645
null
null
Thermodynamics
27.816073
Astronomy
19.139891
Thermodynamics
[ 36.82421112060547, 8.701558113098145 ]
I. " Actinometrical Observations among the Alps , with the Descrip. . tion of a new Actinometer . ' ' By the Rev. GEORGE C. HODGKINSON . In a Letter to Professor STOKES , Sec. R.S. Communicated by Professor STOKES . Received December 2 , 1866 . SIR , --I have the honour to forward you an account of some actinometrical observations made last summer on the summit of Mont Blanc and at Chamonix , and at the same time to thank the Committee of the Royal Society for the grant which they were so good as to vote me for that object . I reached Chamonix on the 7th of July , in bad weather , which had been prevailing for some time , but which ushered in a fine week very opportunely for my work . After allowing a few days for the weather to settle and for the snow to consolidate , I left Chamonix in the afternoon of Friday the 13th for the Grands Mulets , having previously arranged for a corresponding series of observations being taken the next morning in the valley . Leaving the Grands Mulets at about 2 ? A.M. on the 14th , I reached the summit of Mont Blanc about 8 A.M. , and proceeded at once to work . I had brought with me from England two of Newman 's mountain-barometers , a thermobarometer of Casella , six small thermometers graduated on the stem ( three for the dry- , and three for the wet-bulb observations ) , three of the tubes described in Appendix ( A ) , with two of the actinometers in each . I carried besides an aneroid by Cooke , which proved to be of excellent quality . The third set of apparatus was taken in some faint hope that I might be able to arrange for a third set of simultaneous readings at the Grands Mulets . In this I was disappointed. . Notwithstanding the greatest care had been taken , one of the barometers was found on the Brevent on the 9th to be deranged , and one of the actinometers to be broken ; and on the 12th a second actinometer was broken at Chamonix by an accident . I thought it best to leave the remaining barometer for the valley observations , and to depend upon the thermobarometer , as being more portable and less liable to fracture , for the readings on the summit . I was eventually obliged to rest satisfied with a single observation of this ; and the downward range of the small thermometer unfortunately proved too 2 n limited for the wet-bulb readings . Thus the meteorological observations at the upper station are of the scantiest . Neither above nor below were the actinometrical readings so continuous as I had wished to make them . I had no one with me on the summit capable of rendering me the smallest assistance ; but it is some consolation to think that , even had this been otherwise , the results could not , under the circumstances , have been materially enhanced . There either did not exist , or I failed to detect , as the sun 's altitude increased , anything like a unifornm progression of actinic power at either station during the limited time in which the observations were continued . The results do little more than determine the ratio of the average intensity at the two stations for a portion of the forenoon . This indeed was the main object which I had in view . For looking at the experience of Principal Forbes under easier conditions , when the continuance of the observations , as long as the clearness of the sky might last , presented no difficulty , I did not at all anticipate being able to trace a dependence of the actinic power on the hygrometric state of the atmosphere . lie thus remarks ( Bakerian Lecture , Phil. Trans. part 2 for 1842 , p. 253 ) of the experiments on the Faulhorn and at Brienz , that " it cannot be affirmed they are sufficient to show the kind of dependence which the opacity has on the dampness , and that the values of the coefficient of extinction do not present any correspondence with the hygrometric variations ; " and again , p. 268 , " It must be confessed that no evident relation to the hygrometric condition of the air appears in the individual observations . " From the experiments of the 14th of July the actinic ratio between the summit of Mont Blanc and Chamonix , from 91 311 " to 101 " 11m apparent time , presents , with a single exception , a gradual decrease from 1 244 to 1*206 . The interest of a comparison of these results with those which Principal Forbes obtained between the Faulhorn and Brienz is unfortunately diminished by the fact that his actinometer was not furnished with an internal thermometer for ascertaining the temperature of the liquid employed . This was ammonio-sulphate of copper , which has a coefficient of dilatation varying from 1 at 60 ? F. , to 2-562 at 32 ? F. , and 0-626 at 100 ? F. His recorded numbers for three hours before and three hours after apparent noon derived from his freehand curve , are as follows : Hour . Ratio . 9 ... ... ... ... ... ... ... . 1'141 10 ... ... ... ... ... ... . 1-214 11..1 ... ... ... ... . . 1'345 12 ... ... ... ... ... ... ... . 1-219 1 ... ... ... ... ... ... . 1-078 2 ... ... ... ... 1-207 3 ... ... ... ... ... ... . . 1-217 At 10 " on the Faulhorn the ratio seems to have been rapidly increasing ; on Mont Blanc it was slowly diminishing . The actual amount of the ratio at 1 Oh is almost exactly coincident in the two cases ; but at 1 1h on the Faulhorn it was 1'345 , a value much higher than any which was obtained at any time on Mont Blanc , or seemed likely to have been obtained at that hour had the observations been continued so long . What share the greater depression of the lower station in the experiments of 1832 , the more complete isolation of the upper station in those of 1866 , or variable atmospheric conditions in both sets may severally have had in contributing to this effect , remains a matter for future investigation . The respective heights of the stations are as follows : English ft. English ft. Faulorn ... ... . 8799 Difference 6853 Brienz ... ... ... 1946 Mont Blanc ... . 15784 Difference 12359 Chamonix ... ... 3425 Professor Forbes gives the numbersFaulhorn. . 8747 Difference 6844 . Brienz ... ... ... . 1903 The sky during the observations was not only cloudless , but , as seen from the summit , remarkably clear . The observations have all been reduced by means of Tables derived from Gmelin 's ' Chemistry , ' vol. i. p. 231 , to what they would have been had the mean temperature of the liquid during each minute been 32 ? F. By a prolonged and careful comparison of actinometers ( K ) and ( A ) , the factor for reducing the indications of ( K ) to the standard of ( A ) was found to be 1-29 . Considerable practice is necessary to acquire expertness in the use of the actinometer employed . It is desirable , as nearly as may be , to work it at such a temperature that the rise in the sun may be equal to the fall in the shade . If the mean of the two mean temperatures of the liquid , in taking the shade observations which precede and follow a given sun , differ much from the mean temperature of the liquid during that sun , a sensible error will be introduced . This , however , is to a great extent eliminated by taking the mean of three , and still more completely by taking the mean of five successive actinic results in column ( I ) . The difficulty of using the instrument was overcome by the kind cooperation of several friends for the Chamonix observations . To the good offices of my cousin , Mr. G. F. Hodgkinson , were added those of a lady , a worthy sister of one of the foremost mathematicians of his year , and her two nieces . Under her auspices an admirable arrangement of the work was made , by which each of the party was responsible for a precise and definite function , the adjustment and direction of the instrument , with the shading and unshading , the watch , the readings , and the records . To this friendly and efficient help I am greatly indebted for whatever success has been achieved . How small this is , no one can be more sensible than myself ; yet I venture to hope that when the difficulty of the undertaking is considered , to those at least who are acquainted with the experience of Principal Forbes in 1832 , 1841 , and 1842 , as given in his Bakerian Lecture , the results will not appear either disappointing or discouraging . The season was extremely unfavourable for the further prosecution of the work . Looking to the imperfection of the instrument employed by Principal Forbes in his observations in 1832 , it would seem to be highly desirable that his experiments on the column of air between the Faulhorn and Brienz should be repeated , and that other pairs of stations , intermediate in character to that and the Chamonix pair , should be essayed . I have selected , in the hope of future opportunities , the following among others : English ft. English ft. Becca di Nona ... . . , 10384 Difference 8415 Aosta ... ... ... ... 1969 and should the Piz Stella prove readily accessible , Piz Stella ... ... ... . 1171 9Piz Stella* e* A. Apparenttiine of com. mencing eachobs . hm8 28s 8 30 8 31 . 8 33 8 342 9 62 989 90 9 11 9 121 9 14 9 152 9 19l 9 21 9 223 9 24 9 25 9 27 9 291 9 31 9 321 9 33 9 352 9 36 9 381 9 39 9 412 9 43 9 442 9 514 9 53 9 542 9 56 9 574 9 59 o1 0o1 10 2 10 5 10 65 10 86 10 92 10 11 10122 10 192 10 21 10 222 10 24 10 252 Observations among the Alps . 325 Summit of Mont Blanc , July 14 , 1866 , Actinometer ( K ) . Sunm. . Teet Change Change Solar Solar ActinoB , C D. , E. |G ha n. gK I. 0 , Initial m inaerChun hade effect Tempo effect remeter Ave , main sun , insliade , rature of ( K ) reAve shads reading . reading . r. liuid . duced xduced . 320 Fr. to ( A ) . x0x0xx0x0x0xx0x0x0x0x0x0x0x0x0x0x0x0x0x0x0x 1732 1172 1238 600 662 2098 1890 2200 1840 2200 1882 2120 1460 1.300 1852 1582 2026 1754 1760 1472 1906 1568 1972 1692 2146 1880 2290 2068 2454 1908 1558 1894 1608 2022 1680 2062 1788 2126 1820 2190 1904 2426 2060 2380 1270 1086 1600 1386 1764 1192 1300 602 714 50 1792 2272 1834 2234 1810 2270 1780 1198 1800 1538 2032 1690 2178 1400 1898 1540 1974 1620 2150 1840 2358 1974 2514 2100 1580 1980 1546.2042 1662 2094 1684 2164 1740 2220 1810 2290 2026 2440 1950 992 1580 1282 1828 1410 128 114 382 394 388 500 450 424 426 406 458 478 446 422 434 414 376 400 386 380 494 442 540 636 612 306 366 390 340 262 314 326 360 366 352 306 316 354 328 348 360 378 386 380 400 430 278 318 354 716 738 718 772 753 788 775 772 789 765 787 789 781 760 788 783 758 783 776 795 792 778 51 50 50 50 50 48 48 49 49 49 49 49 50 50 50 50 51 51 51 52 52 52 708 730 711 . 764 745 781 768 764 781 757 779 781 773 752 780 775 750 774 768 786 913 942 917 986 961 1007 991 985 1007 977 1003 1007 996 970 1006 1000 967 999 991 1014 955 995 994 993 996 998 1002 992 988 993 994 1001 783 1010 769 992 The recorded numbers denote tenths of the scale which is divided to millimetres , the last figure being assigned by estimation . _ __ _ . I. t_ Chamonix , July 14 , 1866 , Actinometer ( A ) . A. B , C. D. E. F. G. H. I. L. Appa'renttime Sun Solar of comSO . Initial TerChange Change effect Tempeeffect Ave. mencing shade rading . minal in sun , inshade , unreratureof reduced rages . each obx . reading . + . duced . liquid . to 32 ? F. servation , hm8 224 X 1230 780 450 8 24 116( ) 1560 400 837 85 811 8 254 X 1514 1030 424 8 27 0 140 1554 414 818 85 793 812 8 28X 1484 1100 3S4 8 30 0 1180 164 ) 460 857 85 831 799 8 311 X 1504 1094 410 '833 O 1204 1614 410 830 85 804 794 8 34 X 1330 900 430 8 36 O 950 1304 354 779 84 755 805 8 37 X 1214 794 420 8 39 0 890 1280 390 814 84 789 803 8 40 X 1230 802 428 8 42 0 842 1310 468 872 84 846 800 8 431 X 8112 802 380 8 45 0 812 1280 468 848 84 822 803 8 461 X 1202 822 380 8 48 0 940 1.380 440 814 84 789 802 8 494 X 1280 912 368 8 51 0 1040 1460 420 795 85 770 791 8 52 X 1312 930 382 8 54 0 1032 1462 430 806 85 781 797 8 55 ' X 1350 980 370 8 57 0 1092 1542 450 820 85 795 795 8 584 X 1452 1080 370:9 00 1182 1660 478 878 85 851a 807 9 11 X 1744 1330 414 930 1394 1780 386 801 86 776 9 44 X 1620 1204 416 9 64 X 1204 800 404 980 890 1324 434 841 84 816 9 91 X 1230 820 410 9 11 0 950 1394 444 844 85 818 821 ? 9 12 X 1264 874 390 9 14 0 1014 148,0 466 856 85 830 807 915 X 1420 1030 390 9 17 0 1124 1554 430 808 85 783 800 9 183 X 1420 1054 366 19 20 0 1220 1670 450 813 85 788 19 21 X 1560O 1180360 9 23 0 1310 17 ; 0 480 9 274 X 1554 1294 260 9 29 0 1414 1914 500 820 86 794 9 304 X 1774 1394 380 9 32 0 1560 2000 440 820 86 794 798 933 X 1870 1490 380 9 35 0 1614 2100 486 831 86 805 811 9 361 X 2024 1710 310 9 38 0 1664 2210 546 876 86 849 809 TABLE ( contnued ) . A. B. C. D. E. F. G , H. I. L. Apparent time Sun Solar Solar of corno n TerChngan C ge fact lere AveO~~~~ , IX~nitiapl effect effect Avemencing hae ad inal in m sun , in shade unr rature reduced raes each obreading . + . duced . of liquid . to 32 F. servation . hm9 394 9 41 9 42 . 9 44 9 454 9 47 9 481 9 50 9 514 10 42 10 6 10 74 10 9 10 1010 12 10 134 10 15 10 164 10 18 to10 19 10 274 10 29 10 302 10 32 10 331 10 35 10 364 X0X0X0X0XX0X0X0X0X0XX0XOXOX 2070 1590 1990 1590 1940 1500 2040 1854 2036 1190 1094 1494 1334 1690 1374 1750 1490 1960 1810 2270 1540 1424 1820 1688 2130 1740 2182 1720 2084 1654 2082 1634 2064 1704 2454 1780 830 1584 1120 1820 1344 1880 1384 2050 1670 1404 1950 1234 1934 1504 2224 1820 2300 1882 494 492 564 600 490 486 506 560 594 510 536 560 350 336 306 336 256 360 374 346 366 290 320 306 316 310 300 837 813 885 896 857 846 862 888 899 821 849 865 0 86 86 87 89 89 90 90 91 93 94 95 811 787 857 869 828 818 833 858 869 792 818 833 822 835 838 826 841 853 814 numbers denote tenths of the scale which is divided to millimetres , the last figure being assigned by estimation . The numbers in column L are the means of the five nearest numbers in the preceding column when not less than two observations precede and follow the one against which the average number is placed , otherwise the mean of the three nearest numbers . The recorded Comparison of Results , Summit of Mont Blanc and Chamonix . M. Blanc . ActinorneChan onix . ter ( K ) reactino meduced to ter ( A ) . actinoraeter ( A ) . 812 799 794 805 803 800 803 802 791 797 795 807 955 ' 821 807 800 995 994 993 798 Ratio of actinometers , Mont Blanc and Chamonix . 1-163 1-244 Apparent time . hm9 34 9 35 9 37 9 38 9 40 9 41 9 44 9 47 9 56 9 59 10 2 10 5 10 8 10 9 10 11 10 12 10 15 10 21 10 24 10 32 ActinomeRatio of ter ( K ) reChamonix actinomeduced to actinomei ters , Mont actinometer ( A ) . Blanc and ter ( A ) . Chamonix . 996 998 ... . . 1002 992 988 993 994 1001 1014 1010 9992 o ... ... 811 809 822 835 838 826 841 853 814 1-228 1-234 1-219 1-212 1-206 Meteorological Observations on summit of Mont Blanc and at Chamonix , July 14 , 1866 . Mont Blanc . Chamonix . IMean Apparent Barometer time . time . TlcrmoThermoThermo . corrected ThermoThermoe meter meter and remeter meter arom ( dry ) . ( wet ) . deed to ( dry ) . ( wet ) . 32 ? F. hmhm8 30 8 25 2690 69 F. F. 8 40 8 35 1.6-86 22 F. Below 20j 9 30 9 25 Boiling ... . . 72 F. . 59 F. 9 45 940 point = 225 F. Below 0 1045 11 0 40 1 F. F. 11 0 10 55 24- . 25 20 . 8 ... . 2 F. 63 F. APPENDIX ( A ) . Description of the Actinometer . The actinoreter employed consists of a thermometer with a spherical bulb one inch in diameter , and a tube , of which an inch and a half next the bulb is , for a reason which will presently be apparent , left unscaled . The succeeding ten inches is made to represent , as nearly as may be , the range 328 Apparent time . hm8 27 8 30 8 33 8 36 8 39 8 42 8 45 8 48 8 51 8 54 8 57 909 11 9 14 9 17 9 24 9 27 9 31 9 32 . _~---~ -g~~~~~~ I ! _ __ IIIII from 40 ? F. to 45 ? F. At eleven inches and a half from the bulb the tube is widened , so that the following inch and a half may represent the range from 45 ? F. to 115 ? F. The tube then finishes in a spheroidal chamber , of which the diameters are about an inch and half an inch . The widened portion of the tube may be dispensed with , as the correction which it serves to ascertain may be otherwise found by means of a Table experimentally constructed for each instrument . In that case the spheroidal chamber , in which the tube will then terminate at eleven and a half inches from the bulb , should be made somewhat larger . The fluid employed is alcohol coloured with a drop of pure aniline-blue . A considerable quantity of air is left in the chamber . As a running column has to be read at a particular instant , great plainness is the first requisite for the scale . On this account graduation on the tube has not been adopted ; but at an inch and a half from the bulb is attached an ivory scale , nine-tenths of an inch broad and eleven and a half inches long ( or somewhat less if the widened tube be dispensed with ) , its other extremity coinciding with the commencement of the spheroidal chamber . This scale is graduated throughout in millimetres . The number of millimetres corresponding to each degree Fahr. on the tube of narrow bore , and to every fifth degree from 45 ? to 115 ? on the widened tube , should be noted on the back of the scale . The principle of the instrument is the same as that of Sir J. Herschel 's ; and it is to be worked according to the directions given by him in The Manual of Scientific Enquiry . ' It was devised for mountain use , where the weight of the Herschel and the fragility of its internal thermometer are elements of difficulty . It has also the advantage of being less costly . The air-chamber is made to serve the purpose of the screw in the HIerschel , viz. that of altering at will , according to circumstances , the range of the thermometer . This is effected by throwing off into the chamber a greater or less quantity of fluid , retaining it there by holding the instrument with the chamber end somewhat lower than the bulb , and working with the remaining column . As alcohol expands unequally between its freezingand boilingpoints , a small correction is necessary , depending on the temperature of the alcohol at the time of working , This temperature is ascertained by noting the point in the widened tube , at which the column stands , when the fluid is thrown off into the chamber . The excess of this temperature above 45 ? F. , the point from which the fluid is thrown off , has to be added to the temperature between 40 ? and 45 ? shownby the head of the working column , in order to have the true temperature . From the openness of the scale , and consequent small range of the instrumentfor any one adjustment , it is necessary to select for working a temperature not much removed from that at which the rise in the sun is equal to the fall in the shade . This temperature , which may be called the temperature of equilibrium , will vary practically , according to the solar intensity , from some 5 ? F. to 20 ? F. above the temperature of the surrounding influences . By driving the fluid into the chamber until the temperature of equilibrium is represented at a point near the middle of the tube , the readings will go on for a considerable time without altering the quantity of fluid in the chamber , and ten inches of graduation are found to be ample under all circumstances . By thus taking all the readings , so to speak , on the balance , a uniformity of proceeding is secured , which is not without its value . The instrument , constructed according to the dimensions here given , will denote the intensity of the noonday sun at the summer solstice near the sea-level in England by about 100 divisions of the scale . Owing to the difficulty of shading satisfactorily , and anomalies found to occur in observing among the snow-fields on the high crests of the Alps , the following contrivance has been adopted : A plain telescope-tube of bright metal , 18 inches long and 27 inches in diameter , open at both ends , ,is pierced in its central section with a circular hole 1to 1inch in diameter , from which springs a flanged shoulder projecting about inch to receive a perforated split bung , which clasps the thermometer-stem and holds the bulb firmly in the centre of the axis of the tube . Two caps , fitted at the ends with clean plate-glass , are made to slide off and on at the two ends to admit of the glasses being readily wiped . By protecting these with a little wadding , the tube serves as a case for two actinometers . In the central section of the tube , made by a plane perpendicular to its axis , and nearly 90 ? from the centre of the circular hole , is a screw to attach the tube to an altitude and azimuth motion , by means of which it may be kept constantly directed towards the sun . Below the joint is provided means of attachment to an alpenstock or iceaxe . The shading is effected by means of a loose-fitting cap , bottomed by a chamber with air-holes . The shadow of the large thermometer-bulb on the lower glass , or on a plane held beneath it , is a guide to a perfect adjustment in the working of the instrument .
112646
3701662
An Eighth Memoir on Quantics. [Abstract]
330
331
1,866
15
Proceedings of the Royal Society of London
A. Cayley
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
2
18
716
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112646
null
http://www.jstor.org/stable/112646
null
108,980
Formulae
84.249622
Biography
14.816341
Mathematics
[ 70.90150451660156, -35.519264221191406 ]
II . " An Eighth Memoir on Quantics . " By Professor A. CAYLEY , F.R.S. Received January 8 , 1867 . ( Abstract . ) The present memoir relates mainly to the binary quintic , continuing the investigations in relation to this form contained in my Second , Third , and Fifth Memoirs on Quantics ; the investigations which it contains in relation to a quantic of any order are given with a view to their application to the quintic . All the invariants of a binary quintic ( viz. those of the degrees 4 , 8 , 12 , and 18 ) are given in the memoirs above referred to , and also the covariants up to the degree 5 ; it was interesting to proceed one step further , viz. to the covariants of the degree 6 ; in fact , while for the degree 5 we obtain three covariants and a single syzygy , for the degree 6 we obtain only two covariants , but as many as seven syzygies . One of these is , however , the syzygy of the degree 5 multiplied into the quintic itself , so that , excluding this derived syzygy , there remain ( 7-1 = ) six syzygies of the degree 6 . The determination of the two covariants ( Tables 83 and 84 post . ) , and of the syzygies of the degree 6 , occupies the commencement of the present memoir . The remainder of the memoir is in a great measure a reproduction ( with various additions and developments ) of researches contained in Prof. Sylvester 's Trilogy , and in a recent memoir by M. Hermit * . In particular , I establish in a more general form ( defining for that purpose the functions which I call " Auxiliars " ) the theory which is the basis of Prof. Sylvester 's criteria for the reality of the roots of a quintic equation , or , say , the theory of the determination of the character of an equation of any order . By way of illustration , I first apply this to the quartic equation ; and I then apply it to the quintic equation , following Prof. Sylvester 's track , but so as to dispense altogether with his amphigenous surface , making the investigation to depend solely on the discussion of the bicorn curve , which is a principal section of this surface . I explain the new form which M. Hermit has given to the Tschirnhausen transformation , leading to a transformed equation , the coefficients whereof are all invariants ; and , in the case of the quintic , I identify with my Tables his cubicovariants , ( x , y ) and 02 ( x , y ) . And in the two new Tables , 85 and 86 , I give the leading coefficients of the other two cubicovariants 03 ( x , y ) and 04 ( x , y ) . In the transformed equation the second term ( or that in z4 ) vanishes , and the coefficient A of z3 is obtained as a quadric function of four indeterminates . The discussion of this form led to criteria for the character of a quintic equation , expressed like those of Prof. Sylvester in terms of invariants , but of a different and less simple form ; two such sets of criteria are obtained , and the identification of these and of a third set resulting from a separate investigation , with the criteria of Prof. Sylvester , is a point made out in the present memoir . The theory is also given of the canonical forms , which is the mechanism by which M. Hermite 's investigations were carried on . The memoir contains other investigations and formulae in relation to the binary quintic ; and as part of the foregoing theory of the determination of the character of an equation , I was led to consider the question of the imaginary linear transformations which give rise to a real equation : this is discussed in the concluding articles of the memoir , and in an annex I have given a somewhat singular analytical theorem arising thereout .
112647
3701662
On a New Method of Calculating the Statical Stability of a Ship
332
335
1,866
15
Proceedings of the Royal Society of London
C. W. Merrifield
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0077
null
proceedings
1,860
1,850
1,800
4
70
1,674
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112647
10.1098/rspl.1866.0077
http://www.jstor.org/stable/112647
null
null
Fluid Dynamics
36.159206
Formulae
21.152904
Fluid Dynamics
[ 56.677978515625, -15.714072227478027 ]
I. " On a New Method of Calculating the Statical Stability of a Ship . " By C. W. MERRIFIELD , F.R.S. , Principal of the Royal School of Naval Architecture . Received January 15 , 1867 . The time required for the calculations of the stability of ships has practically restricted the ordinary draughtsman to the use of the metacentre . This implies that the locus of the centres of buoyancy cuts the transverse midship plane in a curve which may be treated as a circle ; and this is only true , in general , for very small limits of inclination . In some particular cases it has been felt desirable to supplement this by computing the moment of stability at some definite angle of inclination , by means of the " ins and outs , " or immersed and emersed wedges . But this has only been applied to one selected inclination , generally of 10 ? or 14 ? ; and owing partly to this , and partly to the very scant time left available to the skilled draughtsman or calculator , this has never been a part of the ordinary work of the computation of a ship 's quantities . For this reason it becomes of great consequence to find some method of getting at the stability , with an amount of extra work , which should not exceed that of the ordinary sheet known as the " sheer-draught calculation"* . A method has occurred to me by which , as I think , this object may be attained . Upon conferring with some of my studentst , who have suggested and removed certain difficulties of detail , we think we see our way , by an easy calculation , to place the whole account of a ship 's statical stability in the hands of any person who understands simple equilibrium , either in an algebraical or geometrical form , as he may prefer . It will take some time , with my present occupations , to prepare detailed examples . But as the method is complete in respect of principle , I have thought it best to bring it at once before the Society . The findamental assumption is , that the locus of the centres of buoyancy can be sufficiently represented by a conic . The stability is then measured by the perpendicular , from the centre of actual weight , on the normal due to the inclination . The chief step , therefore , is to find the conic , of which , I may remark , we already know the vertex , and the tangent and curvature at the vertex ; for these are given by the ordinary calculation of the centre of buoyancy and the metacentre . Now I observe that the conic is completely determined if we can find the length of another radius of curvature corresponding to a known inclination . This is obtained by finding the moment of inertia about one of its principal axes ( longitudinal ) of the plane of floatation at the inclination . This , divided by the unaltered displacement , gives the radius of curvature required . But the chief practical difficulty lay in finding the means of drawing an inclined water-line across the body plan , so as to give an unaltered displacement . This I have at length succeeded in overcoming , as follows . The sheer-draft calculation gives us , inter alia , the areas of the level sections , belonging to the upright position , as rectangles . Now , if we make one side of each of these equal to the length of the ship , their breadths form a series of ordinates for a curve of mean section ; that is to say , the transverse section of a cylindrical body , of which the displacement at any level immersion will be the same as that of the ship . We then make out a scale of displacement for this section at various immersions , for a selected inclination , taking care to measure the immersions on the middle line of the original body plan . By this means the finding of any water-line at the selected inclination is reduced to a problem of plane geometry ; and it is obvious that the place of the water-line so found will be a very close approximation to that of the required plane of floatation in the ship . The calculations are as follows:1 . Take out the horizontal areas from the sheer-draught calculation , and divide each by the ship 's length . Set them off right and left from a vertical line at their present vertical interval , and draw a curve through their ends . 2 . Any practised draughtsnan will have little difficulty in drawing , at sight , an inclined line of floatation which shall give an unaltered immersed area on this mean section . He can verify it by measuring the immersed and emersed triangles obtained by his first guess , and make the correction due to the difference , if they do not agree . 3 . In strictness , the more accurate course would be this , -through each of the vertical stations draw right lines at the selected angle . Thence , by Simpson 's rule , form a scale of areas , ending at the highest inclined waterline . Use the vertical interval of the upright displacement , and neglect the cosine of the inclination . Then divide the upright displacement by the ship 's length and by the cosine of the inclination , and find to what immersion this displacement corresponds in the scale of inclined areas . But this is needless , unless the calculations have to be made for different draughts of water . 4 . Use this immersion to draw the inclined plane of floatation in the body plan . 5 . Calculate the area , common moment , and moment of inertia of this plane , about the longitudinal axis formed by its intersection with the original plane of floatation , upright . 6 . Transfer this moment of inertia to the longitudinal axis passing through the centre of gravity of the inclined plane of floatation . 7 . Divide the moment so found by the displacement . This will give the radius of curvature of the locus of the centres of buoyancy , corresponding to the selected inclination . The conic is now implicitly determined . It remains to show what use is to be made of these data . Let po be the radius of curvature , corresponding to the angle 0 , made between the normal and axis of a conic ; then ( pa(i--e2 ) . ( 1--e2 sin2 0)2 From these we obtain 22 e2=po -Po 22P -p ' cos ) 01 -e"2 , ... ... ... ... ... ... ( b ) poPo sin2 0 Poiop scos . ( oo _ p04p0 cos2 0 Po'-o --Pos ) eo-o= 2os 2o ; ... ... ... ... ... ... ... . . ( ) and these afford the means of calculating all the elements of the conic . Now , let us take any other inclination 1 : we may calculate pi from the foregoing value of e2 by means of the formula P o-2 ... ... ... ... ... ... ... ... ( e ) ( P ( 1--e sing ) : . ' Now , if X be the distance of the centre of gravity of the ship below the metacentre of the upright position , and p the perpendicular from the centre of gravity on the normal of the conic in the inclined position , we shall have 2 ( 2 2 ) ? ( - ? ; * ... ... ... ... . . ( f ) sill p.-+( p( cos and pxD is the moment of stability , D being the displacement . Strictly , it is only necessary to use the formule ( a ) , ( e ) , ( f ) in actual work . Formula ( f ) shows clearly how an alteration in the position of the weights affects the stability . If X be altered , the altered value of p is obtained ( geometrically ) by a very obvious construction . In Mr. Scott Russell 's treatise on ' Naval Architecture , ' p. 604 , it is shown how the stability may be obtained by geometrical construction when the conic is known . It is worth while to remark that the condition that the conic should be a hyperbola , a parabola , or an ellipse , is po < , - , or > P. cos3 0 ; and whether the ellipse is referred to its major axis , becomes a circle , or is referred to its minor axis , depends upon whether Po- , = , or > p ; 0 having any value whatever within the limits of continuity . It is to be observed that this method only applies on the supposition that there is no abrupt discontinuity . The immersion of the gunwale , for instance , would vitiate it . But in ordinary ships , experience leads to the conclusion that a conic would be a very accurate representation of the locus of centres of buoyancy within all reasonable limits . I have not waited to try the method throughout upon a specific example . But every step is separately well known ; most of the steps familiarly so , within my own experience . My estimate of the extra amount of work is , that it would be rather less than would be involved in making an independent calculation of the ordinary sheer-draught work . I shall have an immediate opportunity of verifying this in my school ; but I wished to announce the method publicly before beginning to teach it .
112648
3701662
Transformation of the Aromatic Monamines into Acids Richer in Carbon
335
339
1,866
15
Proceedings of the Royal Society of London
A. W. Hofmann
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0078
null
proceedings
1,860
1,850
1,800
5
57
1,752
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112648
10.1098/rspl.1866.0078
http://www.jstor.org/stable/112648
null
null
Chemistry 2
94.908417
Biography
2.162019
Chemistry
[ -44.779354095458984, -60.74187469482422 ]
II . " Transformation of the Aromatic Monamines into Acids richer in Carbon . " By A. W. HOFMANN , LL. D. , F.R.S. Received January 21 , 1867 . In a previous communicationi to the Royal Society I have described the formation of methenyldiphenyldiamnine , a substance which I obtained some years ago , by the action of chloroform on aniline , by means of a new method , namely , by treating a mixture of phenylformamide and aniline with trichloride of phosphorus . The continuation of these researches necessitated the preparation of phenylformamide , and later also of tolylformamide in greater quantities . I have repeatedly obtained these bodies by the action of formic ether on the corresponding monamine , but in consequence of the difficulties with which the preparation of formic acid in large quantities is still beset , I have of late returned to the old method , viz. , distillation of the oxalate of the monamine , since I found that by employing the materials in the appropriate proportions , the formation of very large quantities of the formyl compounds may be readily accomplished . According to Gerhardt , the principal product of the distillation of the secondary aniline-oxalate is diphenyloxamide , phenylformamide being formed only as by-product . In fact , 1 molecule of oxalic acid and 2 molecules of aniline yield almost exclusively diphenyloxamide by the separation of 2 molecules of water from the secondary aniline-oxalate , thus:(C2O2 ) " r 11 H1 ( C202 ) ) " ~(C2 ' }2 +2H ( C 2 ) + 2H 0 . * Proceedings of the Royal Society , vol. xv . p. 55 . But nothing is easier than to change the conditions of the experiment so as to give rise to the almost exclusive formation of phenylformamide . Act with 1 molecule of oxalic acid on 1 molecule of aniline ( or even with 3 molecules of oxalic acid on 2 molecules of aniline ) , taking care to give at once the highest possible temperature , and phenylformamide will be nearly the only product , 1 molecule of water and I molecule of carbonic acid separating from the primary aniline oxalate at first formed , ( 2O , ) - ? Cj H ? N C 0H N+O+ CO. 2 tH H The distillate is a fluid of peculiar odour , which , on the addition of a strong solution of caustic soda , immediately solidifies to the crystalline sodacompound of phenylformamide . This crude product always containing a quantity of aniline , is sufficiently pure for the preparation of methenyldiphenyldiamine previously described by me . It is only necessary to treat the distillate with trichloride of phosphorus to obtain the methenylcompound in abundance . The action of oxalic acid on aniline at a high temperature gives rise , however , to quite a series of other reactions subordinate to the principal changes , but affecting nevertheless a goodly quantity of material . Carbonic oxide is observed to be evolved , together with carbonic acid , during the distillation . It is the result of two secondary processes . In the first place , phenylformamide already formed splits up , according to the analogous decomposition of formamide , into aniline and carbonic oxide , CHO 1 c , H5 C , 11 N IH N } + CO ; HJ H ) and secondly , diphenyloxamide undergoes a transformation , previously pointed out by me , being changed into diphenylcarbamide with separation of carbonic oxide , ( C , ) N , ( C O ) " ( C , 11)2 N ( C6 if)2 N+C0 On this occasion the formation of the latter body was once more satisfactorily proved by special experiment . During the distillation a considerable quantity of a crystalline substance saturated with oil had solidified in the neck of the retort . This substance was purified by washing with cold and recrystallizing a few times from hot alcohol ; combustion showed that it was pure diphenylcarbamide . The crude oil obtained by the distillation of 1 molecule of aniline and 1 molecule of oxalic acid contains , further , hydrocyanic acid , and it is not difficult to explain in a satisfactory manner the origin of this compound . WVhen the distillate is heated to ebullition with concentrated hydrochloric acid , an oily body passes over with the steam . This oil has a peculiar odour , recalling that of benzonitrile , and exhibits an inclination to crystallize ; it is readily proved to be a mixture . If this substance be boiled for some time with a concentrated soda-solution in alcohol , it partly dissolves with evolution of ammonia . When the fluid is allowed to cool , after ammonia has ceased to be evolved and the alcohol distilled off , its surface is found to be covered with oily drops , which after a time become a crystalline solid . This solidification is instantly produced by treating the oil with a small quantity of concentrated hydrochloric acid . When a few drops of strong nitric acid are added to the hydrochloric fluid in which the crystals are floating , and the mixture is then gently heated , a deep blue colour is produced . This reaction is characteristic of diphenylamine , with which the crystalline body perfectly accords in every respect . It cannot be doubted that diphenylamine is produced from phenylformamide as a product complementary to hydrocyanic acid ; 1 molecule of phenylformamide and 1 molecule of aniline contain the elements of 1 molecule of diphenylamine , 1 molecule of hydrocyanic acid , and 1 molecule of water . CHO } CN I4 C-IH5 } Cell SN+ HN C= I c1N + CHN + H10 . HJH i ? J It still remains to give an account of the fluid substance formed together with diphenylamine , which had disappeared with evolution of ammonia when the mixture was heated with soda-solution . Had not both its odour and its behaviour with soda pointed to benzonitrile , all doubt of the formation of this body would have been removed , when upon addition of hydrochloric acid to the filtered sodic liquid an abundant quantity of the purest benzoic acid was separated , the nature of which was , moreover , fixed by an analysis of the silver-salt . The formation of benzonitrile is easily explained . It is produced by a secondary transformation of phenylformamide , from which 1 molecule of water separates , CH0 06Q1 N 0711 5N + 1120 . The transition of phenylformamide into benzonitrile is only in part accomplished during the distillation of the mixture of aniline and oxalic acid . The greater portion of the nitrile is evidently formed during the treatment of the crude product of the distillation with hydrochloric acid . The conversion of aniline into benzoic acid , an acid richer in carbon than this base , claims some interest , inasmuch as the development of the manufacture of coal-tar colours places the aromatic monamines at our disposal in abundant quantity , and at the cheapest price . It was by no means improbable that some of the acids , already known , might in this manner be more easily prepared than heretofore , nor was it doubtful that the formation of many new compounds could be accomplished by this process . 2 I have therefore , in the first place , endeavoured to establish the generality of the reaction by treating toluidine in a similar manner . The phenomena observed when a mixture of 1 molecule of toluidine with 1 molecule of oxalic acid is distilled , are perfectly analogous to those presented by the corresponding experiment with aniline . It was not necessary for the purposes of the investigation to trace step by step the several phases of the complicated processes . The crude distillate , which contained abundance of tolylformamide , was therefore immediately heated with strong hydrochloric acid and submitted to distillation . The oily substance which distilled over with the water , evolved ammonia on being boiled with soda-solution , and the filtrate from the insoluble residue yielded , on addition of hydrochloric acid , a crystalline acid which combustion , as well as analysis of the silver-salt , proved to be tolylic acid . Here also tolylformamide gave rise to tolonitrile , from which tolylic acid subsequently was produced . c2 Oj i C , i0 C0110 ( O2 } 0+ H}N= C07H }N+ I20 + CO , , 2JHJ H1 CH101 CeH7 rN = CSt N+ 112 0 , H C81H7N + 211H20 = CSH02 + H11 N. Several varieties of tolylic acid are known to exist , and it can scarcely be doubted which of the isomeric modifications is formed in this case . As , however , I intend to follow this reaction somewhat further , I shall not for the present go deeper into the question . The experience collected in the phenyland tolyl-series , as might have been expected , has also been confirmed in the naphthyl-series . The investigation of the naphthaline group in this direction appeared more particularly interesting . The idea naturally suggested itself of completing this group by taking advantage of the new reaction for the formation of a series of compounds , the existence of which had long been pointed out by theory , but the preparation of which as yet , notwithstanding repeated attempts , had not succeeded . Naphthaline , the most common product of the action of high temperatures on organic bodies , has , singularly enough , not as yet been traced to a simple reaction . It was not doubtful that the hydrocarbon would in time be met with as the result of the splitting up of an acid , holding to it a relation similar to that which obtains between benzoic acid and benzole . This acid , which is represented by the formula C1l I8 02 , , is in fact procurable by the action of oxalic acid on naphthylamine , the monamine of naphthyl-series . I propose to give a detailed account of this interesting compound and of its derivatives in a subsequent communication . I cannot conclude this note without expressing my best thanks to Mr. Cornelius O'Sullivan for the assistance he has given me during the performance of the experiments which I have described .
112649
3701662
On the Elimination of Nitrogen by the Kidneys and Intestines during Rest and Exercise, on a Diet without Nitrogen
339
355
1,866
15
Proceedings of the Royal Society of London
E. A. Parkes
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0079
null
proceedings
1,860
1,850
1,800
17
389
8,117
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112649
10.1098/rspl.1866.0079
http://www.jstor.org/stable/112649
null
null
Biochemistry
52.015709
Biology 2
20.144031
Biochemistry
[ -43.99814224243164, -23.37360382080078 ]
" On the Elimination of Nitrogen by the Kidneys and Intestines during Rest and Exercise , on a Diet without Nitrogen . " By E. A. PARKS , M.D. , F.R.S. Received January 23 , 1867 . The experiments recorded in this paper were undertaken to test the results arrived at by Professors Fick and Wislicenus , with respect to the elimination of nitrogen during exercise on a non-nitrogenous diet , as recorded in the Philosophical Magazine for June 1866 ( Supplement ) . Although these results are supported by the previous experiments of Dr. Speck , who has shown that if the ingress of nitrogen be restricted , bodily exercise causes no , or a very slight increase in the elimination of nitrogen by the urine , it appeared desirable to carefully repeat all the experiments , not only because the question is one of great importance , but because objections might be , and indeed have been , reasonably made to the experiments of Professors Fick and Wislicenus on the ground that no sufficient basis of comparison between periods of rest and exercise was given ; that the periods were altogether too short , and that no attention was paid to the possible exit of nitrogen by the intestines . In making the experiments , I was fortunate in being permitted to use the services of two perfectly healthy soldiers belonging to the Army Hospital Corps , and doing duty at the Royal Victoria Hospital at Netley . When soldiers are steady and trustworthy , as these men were , they are good subjects for experiments of the kind , as they are accustomed to very regular diet and occupation , and moreover , from their habits of obedience , carry out all instructions with great precision . The satisfactory results of my experiments , as shown by the almost perfect agreement in the effect on each man , is owing essentially to the very great care with which these two intelligent men carried out every rule which was laid down . One of these men , S. , is an admirable example of an average man ; he is 22 ? years old , 5 feet 8 inches in height , weighs close upon 150 lb. , is strong , with large bones and firm muscles , with sufficient but not excessive fat ; he is very temperate , and is no smoker . He has never been ill in his life . The second man , T. , is also a perfectly healthy man , and has only been ill twice , once in China six years ago with tertian ague , and about three years ago with intermittent hemicrania . But he is in size and weight a good contrast to S. He is 36 years of age , very well proportioned and active , but is only 5 feet 4 inches in height , and weighs only lbs. HIis size is not owing to any imperfection in make or nutrition , but to the fact that he comes of a small race , his father being small , and his mother remarkably so . i-e has small bones , good firm muscles , but very little fat . In fact , he is a thin man . In the following experiments , the amounts of the total nitrogen of the urine ( by sodalime ) , of the urea , of the chloride of sodium , and on certain occasions of the phosphoric and sulphuric acids , were determined . The urea was determined by Liebig 's solution , the chlorine being first eliminated , the phosphoric acid by acetate of uranium , the sulphuric acid by baryta and weighing . The urine was collected from 8 A.M. to 8 A.M. , and great care was taken not to lose any , and to pass it at the exact time . The amount of water , solids , and nitrogen passed from the bowels were also determined on several occasions . All the ingesta were most carefully weighed and measured , and the amount of water in the crimb and crust of bread and in the meat was determined . The nitrogen in the bread was also determined , but the long time demanded by the other processes prevented a complete analysis of the other food ; this was , however , a matter of no importance as regarded the immediate object of the inquiry . The experiments were commenced on December 6 , 1866 , and were continued daily till December 23 . First Period of ordinary regulated Diet and Occupation . The men were first kept under observation for six days , in order to determine the variations in weight and in the excreta , and to see if the metamorphosis of tissue appeared to be healthy . This was found to be the case ; in fact , more completely healthy urinary and intestinal excreta could not be conceived . The weight of the body ranged nearly 1 lb. avoir . , or 1 kilog . above and below the mean amount in each man . The daily average amount of food and drink was only slightly different in each man , and the quantity taken from day to day was very uniform . The men were not placed on any absolute quantity , but ate according to appetite within narrow limits . Average daily amount of food in ounces avoirdupois in this period:*s . T. Cooked meat ... ... ... ... ... ... ... ... ... . 7-625 7'625 Bread ... ... ... ... ... ... ... ... ... ... ... ... . 16'66 16'26 Vegetables:potatoes , ~ cabbage ... ... ... ... . . 13'87 13 Butter ... ... ... ... ... ... ... ... ... ... ... . . I1 Tea , including 3 oz. of milk , and 11 oz. sugar ... . 20 20 Coffee , including 3 oz. of milk , and 1Ioz . sugar ... . 20 20 Beer ... ... ... ... ... ... ... ... ... ... ... ... . . 15 15 W ater ... ... ... ... ... ... ... ... ... ... ... . 5'8 2-33 S. took about *5 oz. salt and T. about '33 , exclusive of salt in food . Adding the water of the so-called solid food to the water taken as drink , the daily amount of food was , in grms. S. T. Water-free solids , in grms ... ... ... 662'2 610 2 Water , in grms ... ... ... ... ... ... . 2334-5 2212'3 Total food ingesta ... ... ... ... ... 2996-7 2822*5 The mean weight of this period was for S. 67'7 kilogs . and for T. 50-6 kilogs . The ingress of solid food per kilog . of body-weight was 9'78 and 12 grms. respectively . The smaller man eat therefore absolutely rather less , but relatively more . During four days of this period the mean daily urinary excretion was , in grms. and cubic centimetresTotal NonChloride Quantity . Sp. gr. rea . Nitrogen nitrogen ureal of in urea . by sodanitrogen . sodium . lime . S ... ... . 1226 1028 25 35-001 16-334 17-973 1-639 14-23 T ... ... . 1335 1020-5 25-925 12-098 13-409 1-313 11685 The excretion of nitrogen was fairly constant from day to day , the range of the urea being , in the case of S. , from 38'37 to 33'36 grms. , or between 2 and 3 grms , above and below the mean amount ; and in the case of T. from 27'68 to 24-906 , or nearly 1 grm. above and below the mean amount . This shows the daily equality of diet and exercise . Calculated for body-weight , the amount per kilog . isUrea . Nitrogen Total Non-ureal in urea . nitrogen . nitrogen . S ... ... ... '517 241 -265 -024 T ... ... ... . '512 '239 -265 '026 The very close relation , indeed identity , as far as the total nitrogen is concerned , of the excretion per kilog . of body-weight in these two men comes out very clearly , and shows that there must be a real connexion between body-weight and urinary excretion . It is remarkable that while the heavier man passed 41 grms. more nitrogen daily from the kidneys than the smaller man , he did not eat any great excess of food . Unfortunately , as the nitrogen in the food was not perfectly determined , it is impossible to know precisely whether the 52 grms. of excess of solid food taken by the larger man would contain 4k grms. more nitrogen . As , however , the amount of meat was precisely the 1867 . ] 341 same , and as the smaller man only took I oz. or 14 grms. less bread , and 25 grms. less vegetables , this would seem to be unlikely , and , if so , some of the nitrogen taken by T. must have passed off in other ways . The mean relation of the ureal to the total nitrogen was very close in each man , being , if the ureal nitrogen is taken as unity , as 1 to 1 1 , and as 1 to 1'108 respectively . From day to day , however , the relation varied . The intestinal excretion was examined only on one day , the last but one of the series . Composition of Intestinal Excretion of Twenty-four Hours . Total Nitrogen weight , in Solids . Water . ingrogen grammes , ! ~in grmmes graminies . S ... ... ... 171-1 28-58 142-52 1-642 T ... ... . 198-47 29-916 168-55 1'98 The smaller man passed rather more solids , water , and more nitrogen than the larger man , and through this channel some of the nitrogen unaccounted for by the urine must have escaped . Whether this would account for the whole of it cannot be stated , as the experiments in respect of the nitrogen in the food and in the intestinal excreta of the whole period were not sufficiently exact to determine this point . On the day when the intestinal excreta were analyzed , the total discharge of nitrogen by the kidneys and bowels was . T. Urine ... ... ... 20 155 13'410 lBowels ... ... . . 1 642 1'980 Total ... . 21'797 15'390 In S. nearly { 1th , and in T. nearly -th of the total nitrogen passed by the bowels . On the day when the intestinal excreta were analyzed , the balance of ingesta and egesta , atmospheric oxygen being disregarded , was as follows : S. T. Weight of body at commencement of } 676 50-76 period , in kilogrammes ... ... ... . Weight of body at close ... ... ... ... . . 6850-89 Gain or loss , in grammes ... ... ... ... ..+ 400 + 130 Total ingesta by food and drink , in 3083 2969 grammes ... ... ... ... ... ... . . Urinary egesta , , ... ... 1619 1774'8 Intestinal egesta , ... ... 171 198'47 Skin and lung egesta , , ... ... 893 866 The tissue-changes in these two men are therefore very closely the same , and the men are quite comparable and well fitted for the experiments . T. has rather a larger excretion ( chiefly of water ) by the kidneys and bowels , and rather less by the skin , hut the difference in not great . He has also a larger excretion of nitrogen by the bowels than S. Second Period.-Non-nitrogenous Diet and Rest . On the day following the men were placed for two days on a non-nitrogenous diet consisting of arrowroot , sugar , and butter , from which the casein had been separated . The only nitrogenous substance taken was that contained in infusion of tea . I thought it better to allow the use of warm tea , without milk , both for the comfort of the men and because I was afraid of deranging the tissue-changes by too complete an alteration of diet . The arrowroot was made into cakes with butter and sugar , and was also taken as jelly . Butter and sugar were taken as desired . I put no restriction on quantity , but left it to choice and appetite . The following was the total diet of two days , December 10th to 11th , and 1 th to 12th , in grammes : S. T. Water-free arrowroot ... ... ... ... ... . . 480 38217 Water-free sugar ... ... ... ... ... ... ... . 399*7 294-8 Total dry carbohydrates ... ... . 879*7 677*5 Butter ( without casein ) ... ... ... ... ... . 1247 84'4 Total water-free food in two days. . 1004'4 761 9 Proportion of fat to carbohydrates 1 to 7 , 1 to 8 . The dry starches and butter being assumed to be of their ordinary composition , the daily amount of carbon would be , in grammes , S. T. In arrowroot and sugar ... ... ... ... ... . . 195*33 150'4 In butter ... ... ... ... ... ... ... ... ... . 49*25 32'83 Total ... ... ... ... . . 244-58 183-23 grms. grms. The amount of water taken in the two days. . 4592 4592 It is of no consequence to calculate the proportion to body-weight , as some starch and sugar passed off by the bowels . During these two days the men were kept in complete rest . They were allowed to get up for fear keeping in bed should make them feverish , but they sat quite still , or lay down on the bed , and did not leave the room during the time . The weight decreased in the case of S. from 67'7 to 66*5 kilogrammes , and in the case of T. from 50'6 to 49'8 kilogrammes . The Urinary Excretion was collected as usual on the first day , from 8 A.M. to 8 A.M. ; but on the second day it was collected from 8 A.M. to 8 P.M. , and again from 8 P.M. to 8 A.M , SO that the last twelve hours ' urine was secreted forty-eight to sixty hours after the last meal of nitrogenous food . The lull details are given further on , and I will now merely state the mean results . On the mean of the two days the urea of twenty-four hours fell from 35 grammes to 16'765 , or more than one-half in the case of S. , and from 26 to 15 , or rather less than one-half in the case of T. The amount of urea in the last twelve hours was only 5 and 4'2 grammes for the two men . The total nitrogen , or a mean of the two days , fell from 17'97 and 13'4 to 8'176 and 7 grammes in the two men , while in the last twelve hours it was only 3'017 and 2 17 grammes , or at the rate of only 6'034 and 4*34 grammes in twenty-four hours . Calculated according to body-weight , the results are per kilogramme : U-rea . Nitrogen Total Non-ureal . in urea . nitrogen . nitrogen . S ... ... ... ... ... ... ... '252 -118 '136 '018 T ... ... ... ... ... ... ... . 301 '-141 '159 -018 A more satisfactory comparison may perhaps be made by taking the last day only as representing more complete nitrogenous inanition . Per kilogramme of body-weight . Urea . Nitrogen Total Non-ureal in urea . nitrogen . nitrogen . S ... ... ... ... ... ... ... -2034 -0949 '1054 -0105 T ... . ' ... ... ... ... ... -2540.1180 '1420 '0130 Therefore during complete nitrogenous inanition the tissues of the smaller and older man furnished a slightly greater amount of nitrogen than those of the larger man , and this is evident both in the ureal and nonureal nitrogen , so that it could scarcely be accidental . The sulphuric acid and phosphoric acids were determined on the last day ; the latter acid was in almost precisely the same absolute mean amount in each man , viz. '9533 and '941 gramme ; the larger man passed , however , one-third more sulphuric acid , viz. '633 as against '427 gramme . In the last twelve hours the chloride of sodium fell to 1 and '42 gramme . The Intestinal Excretion . This was examined on the last day . The composition was-in grammes . in grEllll geS | Solids . Water . jNitrogen . S ... ... ... ... ... ... ... 4253 66 3593 '3875 T ... ... ... ... ... ... ... . 3544 655 28-89 '5360 344 [ Jan. 31 , The amount of solids was almost identical , but S. passed less nitrogen than T. , as occurred also in the first period . The excreta were quite bilious , and had a greenish tint . On the second day of nitrogenous inanition the balance of ingesta and egesta was as follows : S. [ T. Weight of body at commencement of period , in kilogrammes ... ... ... ... ... ... . . 66*89 50*1 Weight of body at close of period ... ... . . 66-19 49*6 Gain or loss , in grammes ... ... ... ... ... . -680 -500 Total ingesta in food and drink , in grammes 2995 2907 Urinary egesta ... ... ... ... . , , . 2477-5 2306 Intestinal egesta ... ... ... . . , , . 45'53 35*44 Skin and lung egesta ... ... ... . 1155 1065-5 The considerable derangement of the usual balance is very evident ; it depended in part on the greater amount of water taken as compared with the former period , but not apparently altogether . The water of the kidneys and the insensible perspiration were increased , while the intestinal water was lessened . There was no sugar in the urine detectable by common tests . The effects of the diet in the two men being thus very similar , a satisfactory basis of comparison was obtained for the period of exercise . Third Period.-Ordinary Food and Occupation . The men then returned to their former regulated diet and usual occupation for four days . Very nearly the same amount of food was taken as in the first period . At the end of four days the weight of the body in each man had returned almost exactly to its former amount . The excretion of urea and the total nitrogen ( which is given in more detail further on ) followed a course very similar in each man . On the first day after the return to nitrogenous diet the urea was in round numbers 14 and 12 grammes respectively below the mean of the first period , that is to say , it was nearly the same as during the first day of nonnitrogenous feeding ; it then , in the case of S. , increased day by day till it reached 29'67 grammes on the fourth day . In the case of T. it increased for two days , but fell a little on the fourth day ; the total nitrogen , however , increased regularly every day . The general result was that whereas in four days of the first period on a similar diet and exercise the excretion of nitrogen was 71'892 and 53'636 grammes respectively , during these four days of the third period the excretion of nitrogen in the urine was only 51-952 and 44-38 grammes ; so that in the case of S. 19-94 and in the case of T. 9'256 grammes of nitrogen were retained in the body for the nutrition of the nitrogenous tissues which had been brought into a state of nitrogenous inanition for two days by cutting off the supply of nitrogen . At the end of the four days it was considered that the tissues had recovered their composition . Fourth Period.-Non-nitr-ogernous Diet and EExercise . Diet.--The diet during this period was of the same kind as in the second period . The men were directed to eat what they pleased of arrowroot made into cakes , and jelly , sugar , and the oil of butter . They took in the two days of December 17-18 , and 18-19 , the following amounts : Non-nitrogenous Food in two days , in grammes , S. T. AVater-firee arrowroot ... ... ... ... ... ... ... ... 796-6 586-8 Water-free sugar ' ... ... ... ... ... ... ... . . 421-5 360'0 Total dry starches ... ... ... ... ... . 1218-1 946-8 Butter ( without casein ) ... ... ... ... ... ... . . 188-5 127'5 Total water-free foocl ... ... ... ... . . 1306-6 1074-3 Proportion of fat to starches ... ... ... ... ... 1 to 6 46 1 to 7 42 ... ... . , ... . . ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The daily proportion of carbon was . T. In starches ... ... ... ... ... ... ... ... ... ... ... ... 270-400 210-189 In butter ... ... ... ... ... ... ... ... ... ... ... ... ... 74-478 50-395 Total . 344-878 260-584 The amount of water drank in the two days was. . 5159'5 4762'6 . Both men eat more during this period , partly because they felt more hungry , partly because the arrowroot-cakes were better made . T. especially took more butter , to which he felt a distaste previously . The diet satisfied hunger ; there was no sinking or craving for other kind of food , but it was monotonous , and neither man wished to continue it . Exercise.-During these two days the men took the following amount of walking-exercise , on level ground . On the first day the exercise commenced at 9 A.M. , and lasted till 7.45 P.M. with intervals . On the second day it commenced at 9 A.M. , and lasted till 9 P.M. The men then went to bed . First day.-23'76 miles=38'23 kilometres . The work done was calculated according to Professor Haughton 's formula , that walking on a level surface is equal to lifting s-Ath of the weight through the distance walked . S. , weight with clothes , 73'68 kilogrammes . Work done = 140839 kilogramme-metres , or 453'6 tons lifted a foot . T. , weight with clothes , 56'33 kilogrammes . Work done = 107655 kilogrammes-metres , or 346-74 tons lifted a foot . Second day.-Distance walked 327 8 miles =-5274 kilometres . Work done . S. =194294 kilogramme-metres . 625S8 tons lifted a foot . T.= 14 7515 kilogramme-metres . = 475 tons lifted a foot . The first day 's walking iwas done pretty well by both men . On the second day both men did the first 20 miles well , but felt very much fatigued during the last 13 miles . During the last 4 miles each man felt pain in the small of his back . Both men could , however , have marched on the following day if necessary . With regard to the amount of fatigue as compared with other occasions , T. would give no opinion , as he said he had no fair basis of comparison . S. , however , was clear that he was much more fatigued than on other food . In 1865 in Ireland he marched 26 miles on one day and 20 on the following , carrying his rifle , accoutrements , and forty rounds of ball-cartridge ( an additional weight equal to 18 lb. nearly ) , and yet he did not feel fatigued at all ; while on the present occasion , marching without weight except his clothes , he felt much exhausted . Both men felt hungry ; the food satisfied them ; neither had any perceptible action of the skin ; the days were fine and rather warm . During these two days S. lost almost precisely 2 kilogrammes in weight , and T. lost 3 of a kilogramme . The Urinary Excretion.-The urine was collected as usual from 8 A.M. to 8 A.M. on the first day , and from 8 A.M. to 8 P.M. , and from 8 P.M. to 8 A.M. on the second day . In order to compare this , I have placed together the chief urinary constituents in the two periods of rest and exercise . Amount of Urine , in cubic centimetres . S. RT . ReAt . Exercise . Rest . Exercise . First 24 hours ... ... ... ... ... ... 2230 2550 2120 1650 First 12 hours of second die 50 1210 190 1000 ( day urine ) ... ... ... ... ... ... ( day urine).0^000"'1 1550 1210 1090 1000 Second 12 hours of socon di day ( night urine ) ... . 910 1020 000 050 Excretion of Nitrogen , in grammes , in Urine . S. T. Tootal nitrogen Total nitrogen Urea . by soda-lime . Urea . by soda-lime . Rest . Eerest . xerest . Ex erExe cise . cise . cise . cise . December 17-18 , fist 20'00 19'125 9'33 10'048 17'3 16'005 8'765 7'994 24 hours ... ... ... ... December 18 , first 1 12 ( day ) hours of 8-525 7-865 4-005 4533 8-45 8-000 4-912 4-522 second day ... ... ... J December 18-19 , lasti 12 ( night ) hours of 5-005 7-140 3-017 3-360 4-2 5-200 2-170 3-553 second day ... ... ... J Total in two days ... 33-530 34-130 16-352 17-942 30-030 29-205 15-847 16-069 The excretion of the urea was very parallel in the two men , and followed this course . In each man in the first twenty-four hours nearly 1 gramme less was excreted by each man in the period of exercise as compared with that of rest ; the larger man excreted nearly 3 grammes more urea than the smaller one . In the next twelve hours each man excreted very nearly ? a gramme less in the period of exercise as compared with rest . The absolute quantity was almost precisely the same in each man ; in other words , the bulk of the larger man now had no effect in the urea . In the last twelve hours ( chiefly rest during night ) the urea increased in each man in the period of exercise , as compared with that of rest , the absolute increase in S. being 2 grammes , and in T. 1 gramme . Taking the whole period , Excretion of urea in two days in the period 1 S. T. of exercise as compared with rest ... ... J 4-060 --'825 The results , when the total nitrogen is considered , are as follows : Slightly more nitrogen was excreted by S. in the period of exercise throughout ; the excess being , gril . In the first 24 hours ... , , ... ... ... . O. 01718 In the next 12 hours ... ... ... ... ... ... . 0 528 In the last 12 hours ... ... ... ... ... . -343 Total excess of nitrogen during exercise period . 1*589 In the case of T. the total nitrogen during exercise was like the urea below the period of rest in the first 36 hours , but in the last 12 hours the excess of nitrogen in the period of exercise was so considerable as to cause the nitrogen of the two days of exercise to exceed that of rest by 0'223 gramme . I draw the conclusion , therefore , that in both these men there was in the first 36 hours a decrease in the amount of urea ; but in the last 12 or rest-hours of the 48 hours of the period of exercise , an increase . That in the case of S. the total nitrogen was increased throughout the whole period of exercise , the total increase being 1'589 gramme , or 24'5 grains of nitrogen , while in the case of T. the total nitrogen , like the urea , was lower in the first 36 hours of the period of exercise , but increased greatly in the last 12 hours . It may , indeed , be said that the difference between the amounts in the two periods is after all so inconsiderable as to be explained by the necessary errors of observation . But the constancy of the results in the two men , and in the case of T. , the amount on the first day after the work-period , as given further on , seem to me to show the excess to be real . On the same diet the heavier man excreted rather more urea and total nitrogen throughout than the smaller man , except in the first 12 hours of the second active day , when the urea was a trifle less . The excretion of nitrogen in the urea , as compared with the total nitrogen , was ( the ureal nitrogen being taken as unity ) as follows:-S . T. Period of rest ... ... ... 1 to 1'042 1 to 1 13 Period of exercise ... ... 1 to 1'126 1 to 1'178 In both cases there appears to have been a greater relative excretion of the nitrogenous substances other than ureal . Is it not probable that the creatinine was increased ? The Phosphoric Acid . S. T. Rest . Exercise . Rest . Exercise . First period of 24 hours ... ... . . 1'873 ... 1144 First 12 hours of second period. . '4930 395 -5102 -5305 Second 12 hours of second period -4603 *749 -4308 -3978 Total in last 24 hours ... . . 9533 1-144 '9410 -9283 On a non-nitrogenous diet the amount of phosphoric acid is not increased in a period of exercise as compared with a like period of rest . The immaterial increase in S. is counterbalanced by as slight a decrease in T. The Sulphuric Acid . est . R T. Rest . Exercise . Rest . Exercise . First 12 hours of second day ( day ) ... 372 '3791 -232 -1544 Second 12 hours of second day(night ) -261 -3084 -195 -3011 Total on second day ... ... ... e ... . The sulphuric acid was slightly increased in each man , but the increase was not great , and is perhaps within the limits of error . Chloride of Sodium . As no chloride of sodium was taken with the non-nitrogenous diet , the amounts excreted represent on the second day the mere waste of the tissues . S. |l T. Rest . Exercise . Rest . Exercise . First 24 hours ... ... ... ... ... ... ... . . 6914 3-280 1i 4-9 1'866 First 12 hours of second day ( day time ) . 281 ( 673 1 88 1094 Last 12 hours of second day ( night time ) . 1-01 -119 I 42 -150 Total of last day ... ... ... ... ... 382 0892 1 2-30 1-244 As the results agree in both men , it appears that on a diet free from common salt much more chloride of sodium passes with the urine during rest than exercise ; it is to be inferred that in the latter case chloride of sodium passes off by the skin . No sugar was detected in the urine by the ordinary tests of liquor potassse and Fehling 's copper solution . Intestinal Excretion . This was examined on the last day , and was as follows : Total weight , Solids . Water . Nitrogen . in grammes . S ... 100'5 5-63 94-87 -5318 T ... 120-7 11-012 119 688 '5739 If these numbers are compared with those of the corresponding period of rest , it appears that the total intestinal excretion was larger , but this arose in one man from an excess of water ; in the other the solids were increased . In both men the nitrogen was in excess in the period of exercise , but the difference was not great , and may probably be disregarded . Balance of Ingesta and Egesta , On the second day of the non-nitrogenous diet and exercise , the balance of ingesta and egesta was as follows:8 . T. Weight of body at commencement of period , in kilogrammes . 66'66 50'1 Weight of body at close of period ... ... ... ... ... ... ... ... . 6573 49-87 Gain or loss , in grammes ... ... ... ... ... . -930 -230 Total ingesta in food and drink , in grammes ... ... . . 3639 3124 Urinary egesta ... ... ... ... ... ... ... ... ... ... ... 2247 1667 Intestinal egesta ... ... ... ... ... ... ... ... ... ... ... ... . 100-5 120-7 Skin and lung egesta ... ... ... ... ... ... ... ... ... ... ... 2221-5 1556-3 If these numbers are compared with those given in the corresponding period of rest , it will be seen that in both men the skin and lung egesta were very greatly increased ( nearly 100 and 50 per cent. respectively ) ; . the intestinal egesta were also much larger ; the urinary smaller , especially in the case of T. , who passed nearly 800 cub. centims. less of urine , though he took more fluid as drink . Neither of the men were conscious of any perspiration . Fifth Period.-Ordinary Diet and Exercise . The men were now again placed on their weighed diet , and took their ordinary exercise for four days , except that on the day following the walk of 33 miles they were tired and rested a good deal . This period has now to be compared with the third period , which followed that of rest . As the amount of diet is very important , I give the mean amount in each of the four days of the third and fifth period , in English ounces . S. T. Third , Fifth , Third , Fifth , Daily amount , in ounces ( 437-5 grains ) . orafThird , orFifth , hird , orFifterh , or after or after or after or after restworkrestworkperiod . period . period . period . Cooked meat ... ... ... ... ... ... ... . 8-5 9'81 6-625 7-87 Bread ... ... ... ... ... ... ... ... ... ... ... ... 17 16-18 16-25 16-75 Vegetables-4 potatoes , cabbage ... ... ... ... ... 1368 1462 135 1437 Butter ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 111 Tea , with 14 oz. of milk , 1 oz. of sugar ... ... 20 20 20 20 Coffee , with same amount of sugar and milk . 20 20 20 20 Ale ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... . . 21 20 18 20 Salt uncertain ... ... ... ... ... ... ... ... ... ... ... ... ... In the fifth period each man took rather more than an ounce more meat ; S. took s8 oz. less bread , and T. 2 an ounce more ; each man took | of an ounce more vegetables , and 1 and 2 ounces more water . It is to be regretted that the diet was not precisely the same ; but the differences are not very great , and it was thought desirable to allow the men to satisfy their appetites . They were more hungry after the work-period than after the rest-period . The weight increased in this period . In two days S. gained 1 kilogramme and T. 1I kilogramme , each man nearly getting his proper weight . The Urinary Excretion , The quantity of Urine . S. T. After restAfter workAfter restAfter workperiod . period . period , period . Mean of 4 days ... ... ... ... ... 1139 1028 1500 1495 There was scarcely any difference in T. , and only 10 per cent. difference in S. The Nitrogen . -S . , T. After restAfter workAfter restAfter workperiod . period . period . period . Total Total Total Total nitronitronitronitroUrea . gen by Urea . gen by Urea . gen by Urea . gen by sodasodasodasodalime . lime . lime . lime . First day ... ... ... ... ... ... 20-67 9-703 20-8 10-237 14-40 7-441 23-00 11-58 Second day ... ... ... . . 25-68 12-304 26-364 13-065 23-00 11-480 24-36 13-00 Third day ... ... ... ... ... ... 26-29 13-704 28-32 14-590 25-20 12-209 24'57 Fourth day ... ... ... ... . . 29-67 14-260 30-10 15-555 22-99 13231 2136 10-395 Mean ... ... ... ... ... ... ... ... 25-555 12-988 26-396 13-361 21-397 11-095 23-322 11-658 Mean of 3 days . Unfortunately , on the third day , in the case of T. , the determination of the nitrogen by soda-lime was not satisfactory , and as some time elapsed before it could be again done , the amount has been omitted . But supposing there was the same relative excess over the ureal nitrogen as in the other days , the total nitrogen would have been 13*97 grms. Adopting this number , the following are the results : . T. Excess of urea in four days in after work-period ... ... ... ... ... ... ... ... 3-364 7-700 Excess of total nitrogen in four days in after work-period ... ... ... ... 1-492 4-560 The question now arises , was this excess of nitrogen excreted during the after work-period the result of the elimination of the products of destroyed muscle during the work-period , or was it the consequence of an excess of nitrogenous food in the four days following the exercise ? S. took 1'31 oz. avoirdupois more meat cooked and 3 oz. vegetables in the fifth than in the third period . The percentage of water in the meat was 57'49 , and if the nitrogen be taken at 2'955 per cent. , there would be in 131 oz. of cooked meat ll1 grm. of nitrogen . In the vegetable there would be about 0-04 grm. of nitrogen . But from this amount must be deducted '325 grm. of nitrogen not taken in the bread , making the total daily excess of nitrogen taken in the fifth period -815 grm. ; the daily excess of nitrogen in the urine was , however , only -375 grm. ; therefore , in the case of S. , it cannot be affirmed that any excess of nitrogen was derived from disintegration of muscle during the exercise . In the case of T. , the daily excess of nitrogen was larger , amounting daily to 1*14 grm. , but as the man took 1'245 oz. more meat , 1 oz. more bread , and almost an ounce more vegetable ( in all 1*2 grm. of nitrogen ) , it is evident that here also the excess of nitrogen in the urine might have been derived from the food . However , it is really probable that some of the very large excess of urea on the first day of this period , in the case of T. , was really owing to augmented elimination from the work . No such excess is observable in the case of S. , who had , however , a larger elimination than T. in the previous twelve hours . The Chloride of Sodium . The chloride of sodium rapidly returned to its previous amount . S. T. First day ... ... ... ... . 1444 1-614 Second day ... ... ... 6-169 4-905 Third day ... ... ... ... 1025 8-513 Fourth day ... ... ... 8117 6-446 It will be remembered that T. always took less salt than S. The third period is not comparable with the fifth , as the men took by mistake a great deal of salt on the second day . The Phosphoric Acid . S. T. First day ... ... ... 1-565 2-158 Second day ... ... ... 2413 2-273 Third day ... ... . 2-548 2-533 Fourth day ... ... ... 2-408 2-065 As the phosphoric acid was not determined in the third period , no comparison is possible , but the above Table shows that no excess passed off in the after-period . The sulphuric acid was not determined in this period . The Intestinal Excreta , in grammes . ' . S.e TT . Total SNitroTotal Solids . Water . Nitroweight . Solids . War . gen . weight . gen . Bec . 19-20 ; first day ... 298 ... ... ... ... ... . . 1275 Dee 20-21 ; second day . 1917 ... ... ... . . 213 Dec 21-22 ; thirdday ... 134-9 21-86 113-02 1-264 71 11-8 592 -7188 Dec. 22-23 ; fourth day . 171-1 ... ... ... ... 191'7 The large intestinal excretion on the first day , in the case of S. , was owing to a little looseness of the bowels ; there were two stools on that , day , being the only instance of irregularity in either man . Otherwise , as compared with the first period , there is no evidence in either case of any increased excretion ; on the third day , indeed , the nitrogen was below that of the first period in each case . The balance of ingesta and egesta was as follows on the third day of this period : S. T. . Weight of body at commencement ... 67-1 50'07 Weight of body at close ... ... ... ... ... 6708 50-08 Gain or loss , in grammes ... ... ... ... -20 +10 Food and drink ingesta ... ... ... ... ... 2891-7 2877-5 Urinary egesta ... ... ... ... ... ... ... ... . . 1808-7 1922-5 Intestinal egesta ... ... ... ... ... ... ... ... 134-9 71 Skin and lungs egesta ... ... ... ... ... ... 968-1 894 These numbers are fairly accordant with those of the first period , except that the intestinal excretion in T. was slightly less , and the urinary rather more . The conclusions which can be drawn from the above experiments are not altogether accordant with those of Professors Fick and Wislicenus . The decrease in the urea during the first thirty-six hours of the exercise-period , as compared with the rest-period , on a diet without nitrogen , which occurred in these two men , is , I think , conformable with the results obtained by the two experimenters mentioned ; but this is not the case with the increase in the urea which I found in the last twelve hours . Yet that this increase is real is shown , I believe , by the accordant results in the two men , and by the increase of the total nitrogen of the exercise-period as determined by soda-lime . The relative greater increase in my experiments of the non-ureal nitrogen ( which makes me believe that an excess of nitrogenous compound other than urea , and possibly creatinine especially , was produced by the exercise ) is not perceptible in their experiments , yet I cannot but believe that the fact was so , as it comes out with great clearness in the two men . The following Table shows this . Relation of ureal to non-ureal nitrogen , the former being taken as unity . S. T. Before rest-period ... ... ... . 1 to 1'1 1 to 1*108 Rest-period ... ... ... ... ... 1 to 1-042 1 to 1-13 After rest-period ... ... ... . . 1 to 1'009 1 to 1-116 Work-period ... ... ... ... ... 1 to 1-126 1 to 1-178 After work-period ... ... ... . . 1 to 1-08 1 to 1 06 ( ? ) ( three days ) . The reason which makes me believe the results are real , is the fact that the individual relation of the ureal and non-ureal nitrogen is preserved ; that is to say , in T. the non-ureal nitrogen is , under normal circumstances , a little in excess as compared with S. ; the same relative excess is also found in the work-period . The reason of these differences between Professors Fick and Wislicenus and myself is probably to be found in the short period of time during which their observations were carried on , and also because the urea was not determined by them in the night of the 30th to 31st of August . But their conclusion is certainly borne out , that on a non-nitrogenous diet exercise produces no notable increase in the nitrogen of the urine-although , when the whole period is considered , it does produce a slight increase . It may now also be said that , under similar conditions , exercise produces no increase in the excretion of nitrogen by the bowels . The diminution in the amount of urea during the actual period of work , as compared with the rest-period , which , if I am not mistaken , is obvious in both our experiments , is a very curious circumstance . It shows , not that on a non-nitrogenous diet the nerves and muscles are totally unaffected by exercise , but that changes go on which either retain nitrogen in the body or eliminate it by another channel . Is it possible that , when the excess of nitrogen is restricted , the exhausted muscle will take nitrogen from the products given off from another portion of decomposing muscle , and thus the nitrogen may be used over and over again ? or , after all , is nitrogen really given off in some form by the skin during exercise , as formerly supposed ? Although it is thus certain that very severe exercise can be performed on non-nitrogenous diet for a short time , it does not follow that nitrogen is unnecessary . The largest experience shows , not only that nitrogen must be supplied if work is to be done , but that the amount must augment with the work . For a short period the well-fed body possesses sufficient nitrogen to permit muscular exertion to go on for some time without a fresh supply ; but the destruction of nitrogenous tissues in these two men is shown by the way in which , when nitrogen was again supplied , a large amount was retained in the body to compensate for the previous deprivation . I believe also that in these two men the great exhaustion of the second day showed that their muscles and nerves were becoming structurally impaired , and that , if the experiments had been continued , there would have been on the third day a large diminution in the amount of work . I have found that the period when a restricted supply of nitrogen begins to tell on the work differs in different men . In one experiment I reduced the nitrogen in the food to one-half its normal quantity in two men : in one , no effect was produced on exercise in seven days ; in the other , a lessening of active bodily work was produced in five days . Doubtless the previous nutrition of the muscle would influence the time . Finally , it may be questioned whether the relation of elimination of nitrogen to exercise can be properly determined in this manner , i. e. by cutting off the supply of nitrogen . The true method would probably be to supply nitrogen in certain definite amount , so that the acting muscle might appropriate at once what it required .
112650
3701662
Account of Experiments on Torsion and Flexure for the Determination of Rigidities. [Abstract]
356
356
1,866
15
Proceedings of the Royal Society of London
J. D. Everett
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
1
14
267
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112650
null
http://www.jstor.org/stable/112650
null
108,972
Measurement
84.733696
Biography
10.849728
Measurement
[ 45.743194580078125, -55.451942443847656 ]
" Account of Experiments on Torsion and Flexure for the Determination of Rigidities . " By J. D. EVERETT , D.C.L. , Assistant to the Professor of Mathematics in the University of Glasgow . Communicated by Sir WILLIAM TiHOMSON . Received January 25 , 1867 . ( Abstract . ) These experiments are a continuation of those described in a paper read February 22 , 1866 , with some modifications in the apparatus employed which render the comparison between torsion and flexure more direct . The amount of torsion or flexure produced by subjecting a cylindrical rod to a uniform couple throughout its whole length , is measured by means of two mirrors clamped to the rod near its ends , in which , by the aid of two telescopes , the reflexions of a scale overhead are seen and the displacements read off . One end of the rod is fixed , and a couple ( of torsion and flexure alternately ) is applied to the other end . Three rods , of glass , brass , and steel , were experimented on , and the results obtained were as follows-M , n , and I denoting the resistances ( in kilogrammes per square millimetre ) to linear extension , shearing , and cubical compression respectively , and odenoting the ratio of lateral contraction to longitudinal extension : Glass . Brass . Steel . Value of M ... ... 5851 10948 21793 , n ... . . 2390 3729 8341 , , k ... ... 3533 57007 18756 , , ... ... . '229 -469 '310
112651
3701662
On the Relation of Insolation to Atmospheric Humidity
356
367
1,866
15
Proceedings of the Royal Society of London
J. Park Harrison
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0081
null
proceedings
1,860
1,850
1,800
12
344
4,099
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112651
10.1098/rspl.1866.0081
http://www.jstor.org/stable/112651
null
null
Meteorology
64.460037
Thermodynamics
18.002777
Meteorology
[ 45.75123596191406, -55.492374420166016 ]
" Account of Experiments on Torsion and Flexure for the Determination of Rigidities . " By J. D. EVERETT , D.C.L. , Assistant to the Professor of Mathematics in the University of Glasgow . Communicated by Sir WILLIAM TiHOMSON . Received January 25 , 1867 . ( Abstract . ) These experiments are a continuation of those described in a paper read February 22 , 1866 , with some modifications in the apparatus employed which render the comparison between torsion and flexure more direct . The amount of torsion or flexure produced by subjecting a cylindrical rod to a uniform couple throughout its whole length , is measured by means of two mirrors clamped to the rod near its ends , in which , by the aid of two telescopes , the reflexions of a scale overhead are seen and the displacements read off . One end of the rod is fixed , and a couple ( of torsion and flexure alternately ) is applied to the other end . Three rods , of glass , brass , and steel , were experimented on , and the results obtained were as follows-M , n , and I denoting the resistances ( in kilogrammes per square millimetre ) to linear extension , shearing , and cubical compression respectively , and odenoting the ratio of lateral contraction to longitudinal extension : Glass . Brass . Steel . Value of M ... ... 5851 10948 21793 , n ... . . 2390 3729 8341 , , k ... ... 3533 57007 18756 , , ... ... . '229 -469 '310 February 14 , 1867 . Lieut.-General SABINE , President , in the Chair . The following communications were read : I. " On the Relation of Insolation to Atmospheric Humidity . " By J. PARK HAIRRIsON , M.A. Communicated by the President . Received January 30 , 1867 . The occurrence of the maxima of insolation on days of grent relative humidity which was noticed by Herr v. Schlagintweit in India* , receives confirmation from the fact that the post-solstitial periods of maximum solar radiation in autumn , and also the diurnal maxima , coincide with monthly and daily periods of maximum lumidity . It is proposed to show the extent to which this is the case in England by means of Tables of monthly results of radiation and vapour . The first Table exhibits the mean monthly values of solar radiation and vapour-tension for the five months from May to September , at Greenwich , in 1860-64* . TABLE I. Monthly Means of Radiation and Vapour at Greenwich ( 1860-64 ) . Month . Solar Tension of Weight of radiation . vapour . vapour . May ... ... ... 97'8F . 0'314 in . 3-5 grs. June ... ... ... 103-2 0-364 4-1 July ... ... +108-2 +0-393 +4-4 August ... ... '+107'5 +0-397 +4'4 September. . 97-5 0-361 4-0 The plus signs ( + ) indicate first and second maxima . The maxima , both of radiation and vapour , occur in July and August . The excess of insolation in July is 5 ? , and the excess in August 4 ? '3 above the mean in June . The excess of vapour-tension in the two months is -030 . To obtain results more exactly comparable , the monthly mean tension of vapour for each of the five months was next deduced at the hours of noon , 2 P.M. , and 4 P.M. , for the years 1842-47 , during which two-hourly observations were made at the Royal Observatory . In Table II . , which contains the monthly means , maximum results again appear principally in July and August . TAELE II . Monthly Means of Tension of Vapour at Greenwich at Oh , 21 , and 41 . Year . May . Junet . July . August . September . 1842 . 0-358 0-473 0-436 0-545 0-449 1843 . 0-390(a ) 0-414 0-501(b ) 0-509 0-474(c ) 1844 . 0-365 0-429 0-466 0-430 0-450 1845 . 0-331 0-493 0-463 0-443 0-402 1846 . 0-379 0-483 0-484 0-496 0-471 1847 . 0-376 0-391 0-484 0-497 0-403 ( a ) Mean amount of cloud 8-0 . ( b ) Cloud 8-5 . ( c ) Cloud 4-5 . And the monthly maxima of solar radiation ( in the next Table ) accord with the higher mean tensions of vapour in almost every instance . TABLE III . Monthly Mean Maxima of Solar Radiation . Year . May . June* . July . August . September . 0o000 1842 . 82-1 98'9 92'4 102-2 81'7 1843 . 80'9(a ) 85-1 90-9(b ) 93-0 92'6(c ) 1844 . 87-5 95-0 94'1 87-2 87-0 1845 . 75-0 93'1 90-3 ( 91.7)t 81-3 1846 . 87-1 103-1 97-4 93-3 90-3 1847 . 86-3 85-7 93-0 89'0 77'6 ( a ) Mean amount of cloud 8'0 . ( b ) Cloud 8-5 . ( c ) Cloud 4 5 . In those cases where the values of radiation and vapour do not agree , the exceptions will , it is believed , be sufficiently accounted for ; thus the occurrence of the second maximum of solar radiation in September 1843 in place of July , though tension was higher in the latter month , is explained by the obscuration of the sun , and the unusual quantity of rain in July . The tension of vapour in September was *06 higher than in June+ . Heat and Vapour in Canada.-The dependence of the maximum temperature in the day on the quantity of moisture in the air , in winter , at Toronto , though not directly connected with the present inquiry , is closely allied to it , and may be referred to with advantage in the absence of observations of solar radiation , to show the effects of slight variations of vapour in that country . General ( at that time Colonel ) Sabine , in a paper in the Transactions of the Royal Society " On the Periodic and Non-Periodic Variations of Temperature at Toronto " ? , pointed out the fact that the period of minimum heat in the year , both hourly and daily , at that station occurs between the 7th and 17th days of February , on the days when vapour is also at its minimum . The means of temperature and tension on the ten days alluded to are respectively 21 ? '7 and '098 , as deduced from the hourly observations which were taken in 1842-48 at the Ordnance Office . The mean readings of the standard thermometer at 2 P.M. ( the warmest hour in the winter at Toronto ) and the contemporaneous mean tensions of vapour , in January and February , are exhibited in Table IV . TABLE IV . Monthly Mean Results at Toronto at 2h P.M. ( 1842-48)* . Month . Maximum Wet.bulb Tension of t*emperature thermometer . vapour . January ... 28-6 26-7 0129 February ... 28-3 25-9 0-117 At 211 on the 7th to the 17th days of February the temperature was 26 ? '4 , and the mean tension of vapour 111 . Postmeridian maxima of solar radiation.-Though , it is well known at observatories , the hour of mean maximum solar heat occurs in this country after midday , there is no numerical proof of the fact available , excepting the results of six days ' observations by Professor Daniell . From experiments made by him in June ( 1822 ) at every hour between 9 " 30 " A.M. and 7h 30m P.M. , the mean highest readings of a black-bulb thermometer were obtained between Ih 30 " ' and 2h . The following are the means for five days:h mn At 10 30 ... . 46 12 30 ... . 63 1 30 ... . 65 2 30 ... . 63 It may be assumed , then , that on days when the sun is shining both in the morning and afternoon , solar radiation is of highest apparent force after 0h . Daily maxima of vapour.-The means of vapour-tension have been deduced at 10h A.M. , noon , and 2h from the bi-horaryobservations at Greenwich in 1842-47 ; the following Table , which contains the monthly results for each of these hours , shows that the means at 21 are higher than those at 10 " A.M. , or at noon , in every month from March to September : : From Tables LV . , LVIII . , and LX . , Toronto Observations , vol. ii . The maxima of heat and vapour occur at Toronto in July and August , vapour-tension at 2h in July being,069 higher , and in August -108 higher than in June . t Daniell 's 'Meteorology , ' vol. ii . p. 113 . + Ibid. pp. 114-118 . On another favourable day in June , Professor Daniell obtained the following results with a solar thermometer covered with black wool:-at 10 A.M. 111 ? ; at noon 129 ? ; at 2h P.r1 . 143 ? ; at 2h 30 " P.r. 138 ? . Since this paper was in type , I find these results are confirmed by observations made in March 1858 by Mr. HI . S. Eaton . TABLE V. Monthly Means of Vapour-Tension at Greenwich at 22 , oh , and 2h ( 1842-47 ) . Hour . March . April . May . June . July . August* . Sept. h 22 -236 0-284 0-357 0'437 0'462 0,473 0-427 0 -246 0'294 0-365 0-446 0-469 , 0'483 0-441 2 +-249 +0-297 +0'368 +0'449 +0-475 +0-486 +0-444 The mean increase of vapour from 10n1 to noon is '010 ; and the mean increase from noon to 2h is '0034 . In six of the months the mean increase is in each case '003jf . The results a3cord with the assumed date of maximum radiation . Actinometer-observations.-The observations of the actinometer made by Mr. Nash at the Royal Observatory in 1864 supply further evidence of the fact that the maxima of radiation occur in the autumn , and after 01 . I have extracted the mean results of the several groups of observations which were taken at or near the same elevation of the sun , in the months of August and September in autumn , and in the months of March and April in spring , and find that the value of the mean increase of the scalereadings in the autumn is about 100 per cent. greater than in the spring+ . The mean increase of the scale-readings in March and April is 19'4 . The mean increase of the scale-readings in August and September is 39'6 . The difference is 20'2 , at the same mean altitude of the sun . The means of the contemporaneous observations of the vacuum-thermometer on the grass were as follows : In March and April ... . . 70 ? '3 F. In August and September ... 84 ? '7 F. The difference is 14 ? '4 . And the mean tension of vapour for the four months is , in March and April '23 , and in August and September '34 . TABLE VI . MAeall Results of Actinometer-observations at Greenwich , March and April 1864 . Mean results Month and Mean solar Mn sle Altitude of in scale-diState of sky . day . time . sun . visions . hm March 23 . 2 29 18-7 30 Light cirri . 15 . 22 23 14-2 32 Cloudless . 18 . 29 21-1 32 Clear . 18 . 0 36 204 3(6 Clear . 24 . 1 32 17-0 36 Clear . 15 . 23 51 19'1 37 Clear . Light cloud . April 15 . 2 26 27-1 37 Clear . 20 . 2 28 25-5 38 Light cirri prevalent . March 24 , 0 49 143 9 Clear , Means ... ... . 19-4 35 Clear . TABLE VII . Mean Results of Actinometer-observations at Greenwich , August and September 1864 . Month and Mea solar Mean resultsAltitude of in scale . di . State of sky . ~day . time ~ visions . shm August 30 . 3 26 41'6 30 Cloudless ( thunder in evening ) . September 14 . 22 8 43-3 34 Sun free from cloud . 14 . 22 12 34*7 35 Light cirri over sun . August 26 . 30 38-3 35 Sun free from cloud . 26 . 2 55 32-4 36 Sun free from cloud . Clear ( amount of 29 . 2 39 40-1 36 cloud in afternoon 9 , cirrocumuli , cirrus ) . 5 . : 33 41-7 39 Cloudless . Means ... ... 39 6 35 Cloud genera Iresent . Of the very few observations in May and July which were available for comparison , the scale-readings in July were found to reach far higher values than in May * . TABLE VIII . Results of Actinometer-observations in May and July 1864 . Mean results Month and Mean solar n sedts Altitude of day . time . visions . SUII . hm May 16 . 2 17 28-3 47 Cloudless* . 16 . 0 28 21-4 56 Cloudless . 16 . 0 14 23-7 57 Cloudless . July 11 . 2 19 46-7 50 Clear about sun . 5 . 17 36-6 58 Clear . 13 . 23 18 39-3 58 Cloudless . The mean tension of vapour in May was 330 , in July '38 . The last Table contains , in parts of scale , the results of groups of observations near midday and 2 P.M. , on three days , in March , May , and July . The maximum in each case occurs at the later hour..TABLE IX . Actinometer-observations at oh and 2h . onean result Month and Mean solar nrel Altitude of in scale-diState of sky . day . time . sun . ^ visions . hm March 24 . 0 49 14-3 39 Clear throughout . 24 . 1 32 17'0 36 Clear . AMay 16 . 0 28 21-4 56 Cloudless . 16 . 2 17 283 47 Cloudless . July 14 . 23 37 48-6 59 Cloudless . 14 . 2 13 57'6 50 ' Cloudless . The great accordance between the foregoing results renders it unnecessary to adduce further evidence of the occurrence of maximum insolation some considerable time after the summer solstice and after 51 . Increased solar radiation supposed to be due to the action of aqieous vapour.-Herr von Schlagintweit , applying Professor Tyndall 's discovery of the absorptive properties of aqueous vapour to the phenomenon of insolation , attributed the high readings of his solar thermometer , in certain parts of India , to the fact that air , when highly charged with moisture , impedes free radiation ; that is to say , the air restores to the instrument some portion of the heat which has been radiated off from it . A like cause has been recently assigned for the variations in temperature which take place on clear nights in Madras under different tensions of va* Compare observations on the same day at Oh 28m and 0 " 14"1 . pour , those nights being considered clear in which the percentage of cloud did not exceed ? 10 . It was found , on a careful tabulation of hourly observations , that the fall in temperature was decidedly greater when the quantity of vapour was relatively smallV . Cloud , haze , and opalescence t of the atmosphere more probably the principal cause of the phenomenon.-It appeared of much importance to ascertain whether the presence of cloud , and the imperfect state of transparency in the sky which usually accompanies it , may not have materially assisted in producing the results alluded to in the last paragraph , and , i fortiori , account for the increased insolation noticed in cloudy weather in v'arious parts of India-e . g. " on days in the rainy season when the clouds are temporarily broken , " and , as in Sikkim , " when a break in the clouds of an hour or two had to be watched for to obtain observations of solar radiation " ( Schlagintweit , 'Meteorology of India , ' pp. 49 & 51 ) . To test this point , the results of the observations for the four years ending 1844 , over which the inquiry at Madras extended , were divided into groups of contemporaneous observations of temperature , vapour-tension , and percentage of clear sky , when the mean numerical results showed that a progressive fall of about 10 F. for every ? 10 of vapour-tension was accompanied by a proportionate increase in the percentage of clear sky , -a result which is the more significant when it is considered that the infusion of visible cloud was limited to '10 . To prevent mistake , the fall in temperature on the nights of maximum clearness was compared with the fall on nights of minimum clearness within the limits above stated . There were twenty-five nights which were estimated to be perfectly clear , and twenty-two nights when the per . centage of clear sky ranged from '90 to 93 , the average being -915 ( 1 000 representing an entirely clear sky ) . The results were as follows The mean fall of temperature at an estimated clearness of sky denoted by 1-000 was 8 ? -3 F. The mean fall of temperature at an estimated clearness denoted by *915 was 6 ? F. The difference is 2 ? '3 . The contemporaneous mean tensions of vapour were -68 and -83 respectively . It is probable then , as cloud accompanies humidity , that tension of vapour gives some indication of the state of transparency of the shy , whilst affording a measure of the quantity of invisible vapour in the air . In any case it is sufficiently clear , both from the results at Madras'and from the slight increase in the tension at 2h P.M. , that the amount of aqueous vapour alone is not sufficient to account for increased or diminished solar radiation . Phil. Mag. October 1866 ; where see Tables and method of deduction . t This term was first used by Professor Roscoe . It here represents the state of the atmosphere at the moment vapour is in process of condensation previously to its formation into cloud . The explanation of the phenomenon of the maxima of insolation occurring on days of great relative humidity in India , however , which has been already alluded to , applies with increased force to the absorptive properties of visible moisture ; and the known action of even the lightest form of cloud in radiating heat to the earth , would point to this as the principal cause of the phenomenon , though it cannot be doubted that some of the effect is due to the action of invisible vapour , whether as warmed directly by the solar rays , or by heat derived from a secondary source . The dependence of terrestrial heat on vapour and cloud.-It was to increased or diminished radiation under a clear or clouded sky that the inflections of the curves of mean temperature , which I communicated to the Royal Society in May 1865 , were ascribed* . The effects produced were on that occasion considered to be principally due to radiation at night t ; but an examination of the daily means proved that a similar action occurred also by day + , the phenomenon in fact depending , as in the case of solar radiation , on the quantity of moisture in the air . The precise values of heat resulting from the action and reaction of solar radiation and vapour cannot be ascertained until mean numerical values have been deduced from a sufficient number of hourly observations to afford trustworthy data for determination . The present paper merely helps to establish a relation between solar radiation and humidity , and suggests an additional cause for the effects which appear to follow from it . APPENDIX . No. 1 . 365 Monthly Mean Maximum Solar Radiation at Greenwich ( 1860-64 ) . Year . May . June . July . August . September . 1860 . 103-7 101.0 10 6 . 103o 97 1861 . 96-7 1086 1145 1165 106-9 1862 . 99-6 103-1 109-4 11077 99'8 1863 , 95-7 104-1 107-2 106-5 92-9 1864 . 93-1 99-3 103-7 100o1 90-7 Means * 978 103-2 108-2 107-5 97-5 No. 2 . Monthly Mean Tension of Vapour at Greenwich ( 1860-64 ) . Year . May . June . July . August . September . 1860 . 0-312 0-357 0-393 0-396 0-364 1861 . 0'284 0-404 0-413 0-436 0-369 1862 . 0-365 0-352 0-394 0-410 0-396 1863 . 0-302 0-364 0384 0-412 0-320 1864 . 0'306 0-344 0-382 0-333 / 0-357 Means* 0-314 0-364 0'393 0-397 0361 No. 3 . Monthly Mean Weight of Cubic Foot of Air at Greenwich ( 1860-64 ) . Year . May . June . July . August . September . grs. grs. grs grs. 1860 . 3-5 40 4-4 4-4 , 41 1861 . 3-2 4-6 4-6 4-9 4-1 1862 . 4-0 4-0 4-5 4-6 4-4 1863 . 3-4 4-1 4-3 45 . 36 1864 . 3-5 3.9 4-2 347 4-0 leans | 3-5 4-1 4-4 4-4 4-0 No. 4 . Vapour-Tension at 10h A.M. at Greenwich ( 1842-47 ) . Year . March . April . May . June . July . August . Sept. Oct. 1842 . 0-263 0-255 0-354 0-453 0-425 0 527 0-442 0-285 1843 . 0-260 0-302 0-383 0-400 0-467 0-498 0-461 0-304 1844 . 0-238 0-320 , 0-352 0-412 0-452 0-423 0-435 0-330 1845 . 0-187 0-282 0 323 0-467 0-459 0-432 0-382 0-349 1846 . 0-261 0-298 0'361 0-516 0-491 0-494 0-465 0-354 1847 . 0-210 0-248 0-372 0-377 0-481 0-465 0-376 0-375 Sums 1-419 1-705 2-145 2-625 2-775 2-839 2-561 1-997 Means * 0-236 0-284 0-357 0-437 0-462 0-473 0-427 0-333 No. 5 . Vapour-Tension at noon at Greenwich ( 1842-47 ) . Year . March . April . May . June . July . August . Sept. Oct. 1842 . 0-280 0-270 0-358 0-470 0-437 0-546 0-447 0-315 1843 . 0-271 0-309 0-390 0-407 0-493 0-499 0-478 0-324 1844 . 0-250 0-337 0-358 0-423 0-459 0-429 0-456 0-343 1845 . 0-190 0-295 0-331 0-488 0-462 0-445 0-397 0-354 1846 . 0-266 0-305 0-377 0-498 0-489 0-491 0-470 0-356 1847 . 0-219 0-247 0-375 0-388 0-476 0-491 0-396 0-389 Sums 1-476 1-763 2-189 2-674 2-816 2-901 2-644 2-081 Means * 0-246 0-294 0-365 0-446 0-469 0-483 0-441 0 347 No. 6 . Vapour-Tension at 2h P.M. at Greenwich ( 1842-47 ) . Year . March . April . May . June . July . August . Sept. Oct. 1842 . 0-284 0-269 0-355 0-472 0-435 0-546 0-447 0-317 1843 . 0-273 0*318 0-393 0-419 0'501 0-508 0-476 0-324 1844 . 0-253 0-346 0 370 0-432 0-470 0-431 0'453 0-346 1845 . 0-197 0-292 0-333 0-496 0-469 0-445 0-408 0-346 1846 . 0-271 0-311 0-379 0-485 0-488 0-491 0-473 0-357 1847 . 0-218 0-245 0-381 0-392 0-486 0-496 0-407 0-381 Sums 1-496 1-781 2-211 2-696 2-849 2-917 2-664 2-071 Means * 0-249 0-297 0-368 0-449 0-475 0-486 0-444 0-345 Fall of temperature at Madras , by nights:1 . 2 . Entirely clear sky ( 1-000 ) . Partially clouded sky ( -915 ) . 25 nights . 22 nights . 40 Percentage of 45 o clear sky . o8.j5 4'8 '900 7.7 62 7.6 5.-9 7'6 11-2 9'5 4-6 -910 9.5 560 9'1 7-5 6-9 7'6 9'6 5.3 9'6 5-4 12-2 5'8 8'1 8'5 9'4 3'6 920 6'6 862 8-2 7'6 65 65'0 6'7 8-7 ___ 8-2 5-7 930 7'5 4'2 10 6 6'4 9-4 4-9 6'5 6'3 25 ) 207-6 22)132-6 8'3 6'0 '915 Mean . At Fort Franklin , Sir John Richardson found that the maximum of solar radiation was obtained in the spring and at noon . Mr. Forbes accounted for this by the fact that the sun 's rays were reflected from the snow , and thus the bulb of the thermometers received reflected as well as direct rays of sunshine .
112652
3701662
On the Conversion of Dynamical into Electrical Force without the Aid of Permanent Magnetism
367
369
1,866
15
Proceedings of the Royal Society of London
C. W. Siemens
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0082
null
proceedings
1,860
1,850
1,800
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http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112652
10.1098/rspl.1866.0082
http://www.jstor.org/stable/112652
null
null
Electricity
80.66127
Fluid Dynamics
14.627623
Electricity
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II . " On the Conversion of Dynamical into Electrical Force without the aid of Permanent Magnetism . " B3y C. W. SIEMENS , F.R.S. Received February 4 , 1867 . Since the great discovery of magnetic electricity by Faraday in 1830 , electricians have had recourse to mechanical force for the production of their most powerful effects ; but the power of the magneto-electrical machine seems to depend in an equal measure upon theforce expended on the one hand , and upon permanent magnetism on the other . An experiment , however , has been lately suggested to me by my brother , Dr. Werner Siemens of Berlin , which proves that permanent magnetism is not requisite in order to convert mechanical into electrical force ; and the result obtained by this experiment is remarkable , not only because it demonstrates this hitherto unrecognized fact , but also because it provides a simple means of producing very powerful electrical effects . The apparatus employed in this experiment is an electro-magnetic machine consisting of one or more horseshoes of soft iron surrounded with insulated wire in the usual manner , of a rotating keeper of soft iron surrounded also with an insulated wire , and of a commutator connecting the respective coils in the manner of a magneto-electrical machine . If a galvanic battery were connected with this arrangement , rotation of the keeper in a given direction would ensue . If the battery were excluded from the circuit and rotation imparted to the keeper in the opposite direction to that resulting from the galvanic current , there would be no electrical effect produced , supposing the electro-magnets were absolutely free of magnetism ; but by inserting a battery of a single cell in the circuit , a certain magnetic condition would be set up , causing similar electro-magnetic poles to be forcibly approached to each other , and dissimilar poles to be forcibly severed , alternately , the rotation being contrary in direction to that which would be produced by the exciting current . Each forcible approach of similar poles must augment the magnetic tension and increase consequently the power of the circulating current ; the resistance of the keeper to the rotation must also increase at every step until it reaches a maximum , imposed by the available force and the conductivity of the wires employed . The cooperation of the battery is only necessary for a moment of time after the rotation has commenced , in order to introduce the magnetic action , which will thereupon continue to accumulate without its aid . With the rotation the current ceases ; and if , upon restarting the machine , the battery is connected with the circuit for a moment of time with its poles reversed , then the direction of the continuous current produced by the machine will also be the reverse of what it was before . Instead of employing a battery to commence the accumulative action of the machine , it suffices to touch the soft iron bars employed with a permanent magnet , or to dip the former into a position parallel to the magnetic axis of the earth , in order to produce the same phenomenon as before . Practically it is not even necessary to give any external impulse upon restarting the machine , the residuary magnetism of the electro-magnetic arrangements employed being found sufficient for that purpose . The mechanical arrangement best suited for the production of these currents is that originally proposed by Dr. Werner Siemens in 1857* consisting of a cylindrical keeper hollowed at two sides for the reception of insulated wire wound longitudinally , which is made to rotate between the poles of a series of permanent magnets , which latter are at present replaced by electro-magnets . On imparting rotation to the armature of such an arrangement , the mechanical resistance is found to increase rapidly , to such an extent that either the driving-strap commences to slip or the insulated wires constituting the coils are heated to the extent of igniting their insulating silk covering . It is thus possible to produce mechanically the most powerful electrical or calorific effects without the aid of steel magnets , which latter are open to the practical objection of losing their permanent magnetism in use .
112653
3701662
On the Augmentation of the Power of a Magnet by the Reaction Thereon of Currents Induced by the Magnet Itself
369
372
1,866
15
Proceedings of the Royal Society of London
Charles Wheatstone
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0083
null
proceedings
1,860
1,850
1,800
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http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112653
10.1098/rspl.1866.0083
http://www.jstor.org/stable/112653
null
null
Electricity
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Measurement
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Electricity
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III . " On the Augmentation of the Power of a Magnet by the reaction thereon of Currents induced by the Magnet itself . " By CHARLES WHEATSTONE , F.R.S. Received February 14 , 1867 . The magneto-electric machines which have been hitherto described are actuated either by a permanent magnet or by an electro-magnet deriving its power from a rheomotor placed in the circuit of its coil . In the present note I intend to show that an electro-magnet , if it possess at the commencement the slightest polarity , may become a powerful magnet by the gradually augmenting currents which itself originates . The following is a description of the form and dimensions of the electromagnet I have employed . The construction , it will be seen , is the same as that of the electro-magnetic part of Mr. Wilde 's machine . The core of the electro-magnet is formed of a plate of soft iron 15 inches in length and 1 an inch in breadth , bent at the middle of its length into a horseshoe form . Round it is coiled in the direction of its breadth , 640 feet of insulated copper wire -L of an inch in diameter . The armature , which is according to Siemens 's ingenious construction , consists of a rotating cylinder of soft iron 82 inches in length , grooved at two opposite sides so as to allow the wire to be coiled upon it longitudinally ; the length of the wire thus coiled is 80 feet , and its diameter is the same as that of the electro-magnet coil . When this electro-magnet is excited by any rheomotor the current from which is in a constant direction , during the rotation of the armature currents are generated in its coil during each semirevolution , which are alternately in opposite directions ; these alternate currents may be transmitted unchanged to another part of the circuit , or by means of a rheotrope be converted to the same direction . If now , while the circuit of the armature remains completed , the rheomotor be removed from the electro-magnet , on causing the armature to revolve , however rapidly , it will be found by the interposition of a galvanometer , or any other test , that but very slight effects take place . Though these effects become stronger in proportion to the residual magnetism left in the electro-magnet from the previous action of a current , they never attain any considerable amount . But if the wires of the two circuits be so joined as to form a single circuit , in which the currents generated by the armature , after being changed to the same direction , act so as to increase the existing polarity of the electro-magnet , very different results will be obtained . The force required to move the machine will be far greater , showing a great increase of magnetic power in the horseshoe ; and the existence of an energetic current in the wire is shown by its action on a galvanometer , by its heating 4 inches of platinum wire '0067 in diameter , by its making a powerful electro-magnet , by its decomposing water , and by other tests . The explanation of these effects is as follows:-The electro-magnet always retains a slight residual magnetism , and is therefore in the condition of a weak permanent magnet ; the motion of the armature occasions feeble currents in alternate directions in the coils thereof , which , after being reduced to the same direction , pass into the coil of the electro-magnet in such manner as to increase the magnetism of the iron core ; the magnet having thus received an accession of strength , produces in its turn more energetic currents in the coil of the armature ; and these alternate actions continue until a maximum is attained , depending on the rapidity of the motion and the capacity of the electro-magnet . If the two coils be connected in such manner that the rectified current from the coil of the armature passes into the coil of the electro-magnet in the direction which would impart a contrary magnetism to the iron core , no current is produced , and consequently there is no augmentation of magnetism . It is easy to prove that the residual magnetism of the electro-magnet is the determining cause of these powerful effects . For this purpose it is sufficient to pass a current from a voltaic battery , a magneto-electric machine , or any other rheorotor , into the coil of the electro-magnet in either direction , and it will invariably be found that the direction of the current , however powerful it may eventually become , is in accordance with the polarity of the magnetism impressed on the iron core . If , instead of the currents in the coil of the rotating armature being reduced to the same uniform direction , they retain their alternations , no effects , or at most very small differential ones , are produced , as no accumulation of magnetism then takes place . I will now call attention to the fact that stronger effects are produced at the first moment of completing the combined circuit than afterwards . The machine having been put in motion , at the first moment of completing the circuit 4 inches of platina wire were made red-hot , but immediately afterwards the glow disappeared , and only about one inch of the wire could be permanently kept at a red heat . This diminution of effect was accompanied by a great increase of the resistance of the machine . The cause of the momentary strong effect was , that the machine from its acquired momentum continued its motion for a few seconds , though it required a stronger force than could be applied to maintain that motion . Each time the circuit is broken and recompleted the same effect recurs . 370 [ Feb. 14 , On lringing the primary coil of an inductorium ( Ruhmkorff 's coil ) into the circuit formed by connecting the coils of the electro-magnet and rotating armature , no spark occurs in the secondary coil . On account of the great resistance of the circuit , which now also includes the primary coil of the inductorium , the current is not in sufficient quantity to produce any noticeable inductive effect . A very remarkable increase of all the effects , accompanied by a diminution in the resistance of the machine , is observed when a cross wire is placed so as to divert a great portion of the current from the electro* magnet . The four inches of platinum wire , instead of flashing into redness and then disappearing , remains permanently ignited . The inductorium , which before gave no spark , now gave one a quarter of an inch in length ; water was more abundantly decomposed ; and all the other effects were similarly increased . I account for this augmentation of the effects in the following way : Though so much of the current is diverted from the electro-magnet by the cross wire , the magnetic effect still continues to accumulate , though not to so high a degree ; but the current generated by the armature , passing through the short circuit formed by the armature-branch and cross wire , experiences a far less resistance than if it had passed through the armature and electro-magnet branches ; and though the electromotive force is less , the resistance having been rendered less in a much greater proportion , the resultant effect is greater . I must observe that a certain amount of resistance in the cross wire is necessary to produce the maximum effect . If the resistance be too small , the electro-magnet does not acquire sufficient magnetism ; and if it be too great , though the magnetism becomes stronger , the increase of resistance more than counterbalances its effect . But the effects already described are far inferior to those obtained by causing them to take place in the cross wire itself . With the same application of force , 7 inches of platinum wire were made red-hot , and sparks were elicited in the inductoriurn 2-e iincles in length . The force of two men was employed in these , as well as in the other experiments . When the interrupter of the primary coil was fixed , the machine was much easier to move than when it acted . For when the interrupter acted , at each moment of interruption the cross wire being , as it were , removed , the whole of the current passed through the electro-magnet , and consequently a greater amount of magnetic energy was excited , while in the intervals during which the cross wire was complete the current passed mainly through the primary coil . The effects are much less influenced by a resistance in the electro-magnet branch than in either of the other branches . To reduce the length of the spark in the inductorium ( the primary coil of which was placed in the cross wire ) to j of an inch , it required the re sistance of 5-1 inches of the fine platinum wire in the cross wire , 5 inches in the armature-branch , and 4 feet in the electro-magnet branch . When there was no extra resistance in either of the branches , the length of the cross wire being only about a few feet , the intensity of the current in the electro-magnet branch , compared with that in the cross wire , was as 1 : 60 ; and when the resistance of the primary coil of the inductorium was interposed in the cross wire , the relative intensities were as 1 : 42 . In conclusion I will mention that there is an evident analogy between the augmentation of the power of a weak magnet by means of an inductive action produced by itself , and that accumulation of power shown in the static electric machines of Holtz and others which have recently excited considerable attention , in which a very small quantity of electricity directly excited is , by a series of inductive actions , augmented so as to equal , and even exceed , the effects of the most powerful machines of the ordinary construction .
112654
3701662
A Brief Account of the 'Thesaurus Siluricus,' with a Few Facts and Inferences
372
385
1,866
15
Proceedings of the Royal Society of London
J. J. Bigsby
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0084
null
proceedings
1,860
1,850
1,800
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http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112654
10.1098/rspl.1866.0084
http://www.jstor.org/stable/112654
null
null
Geography
38.938344
Biography
25.648705
Geography
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" A brief Account of the Thesaurus Siluricus , ' with a few facts and inferences . " By J. J. BIGSBY , M.D. Communicated by Sir R. I. MURCHISON , Bart. Received January 28 , 1867 . I have been led to attempt the preparation of a general view of Silurian life , as far as now known , by my own frequent want of such a record or muster-roll of the constituent members of this great initiatory division of palaeozoic zoology , -a task which has been made pleasant by some personal knowledge of two countries rich in the earlier formations . I have been further encouraged by the great accumulations of the last few years , through the establishment in North America and elsewhere of numerous colleges , each of them having become the centre of more or less field-work . Far more aid still has been derived from many public surveys on a tolerably liberal scale . Nor can we forget the highly meritorious and successful labours which have been , and still are , carried on by private individuals in almost every part of Europe and North America . As this undertaking required an exactitude and a critical skill in determining species and genera according to late improvements in classification , much beyond an ordinary acquaintance with Silurian life , after my materials were put together , I obtained the very valuable aid of Mr. J. W. Salter , late Palmontologist at the London Museum of Practical Geology . I was then , through the kindness of Sir Roderick I. Murchison , Bart. , ,allowed to submit my manuscript to Robert Etheridge , Esq. , F.R.S.E. , 372 [ Feb. 21 the present Palceontologist to the Institution over which Sir Roderick presides . To the careful superintendence of these two eminent naturalists I am indebted for corrections and suggestions of the greatest importance , and particularly as relates to Britain and to Europe generally . My matter has been principally found in the voluminous and truly priceless writings of Murchison , Sedgwick , Barrande , Sowerby , DeVernenil , James Hall , McCoy , Salter , Billings , Angelin , Eichwald , Shumard , and Davidson--together with those of other authors , some of whom are scarcely of inferior merit* . I have been favoured with many unpublished contributions from my friends Mr. Billings ( the learned Paleeontologist of the Canadian Survey ) and Principal Dawson , F.R.S. , of McGill College , Montreal , also , through the kindness of Mr. Salter , from the Himalayas ( Colonel Strachey , R.E. ) , from West Tasmania ( Dr. Milligan ) , from South Wales ( Henry Hicks , Esq. ) , and from the late Mr. Wyatt-Edgell . I propose to give to this effort the name of " Thesaurus Siluricus . " Besides its use for general reference in the closet and in the quarry , the ' Thesaurus ' provides a high station from which the student may obtain a broad survey of the Silurian populations of the whole earth . It will assist in tracing the extent , shape , and varying depths of areas , in discovering regional affinities , differences , and those great zoological severances which we call breaks . By its aid we may compare horizons remote from each other , and , moreover , note the frequent changes of many kinds which take place while the epoch is working out its long history . It . will place under our examination numberless communities of life , their constituents , habits , rise , and decline . The 'Thesaurus ' points to the universality ( as defined ) at times proximate everywhere , brings into prominence the riches , magnitude , and wide diffusion of the Primordial stage ; illustrates the power of locality over life , and opens out the wonderful march of geographic dispersion through obstacles innumerable . For a long period naturalists have been arranging the life of the globe into species , genera , orders , &c. , with a view to the establishment of types as standards of comparison . It is from such data , well considered and generally acknowledged , that this ' Thesaurus ' has been compiled . As long as an individual mollusk remains unregistered it is deprived of its full usefulness ; but even then it may reveal an important fact--as the trilobite speaks of the Palaeozoic period , and a nummulite of the Tertiary . Until some such record as the present is available , the labours of many living investigators ( whose names rise to the lips spontaneously ) will rest comparatively fruitless . It has hitherto not been possible to consider widely scattered existences in an aggregate form . Facts ( many ) have been stored up separately ; but generalized truths have been rarely attained . This has not yet been done in a satisfactory manner , not even by Bronn or Goldfuss for any one epoch , and scarcely for the cretaceous period by the American geologist Mr. Gabb , although he has done well . This 'Thesaurus ' contains 7553 species , and therefore gives abundant scope for profitable study ; but probably it does not give the tithe of the whole Silurian life yet lying buried in the wilds of the Arctic Circle , of -Iudson 's Bay , Labrador , the two Americas , Scandinavia , Australia , India , &c. &c. The more accessible countries frequently , to this day , yield new forms , although the search for them is capriciously and idly conducted , and is dependent often on the accident of a new public work or the presence of a competent observer . Many undescribed species are lying in local museums , still more in the great collection at Prague in the possession of a high Ecclesiastic in that city . Owing to the enlightened perseverance of M. Barrande , a few small parishes close to Prague have yielded nearly one-third of the whole earth 's Silurian remains within present knowledge ; and the greater part of these are not met with elsewhere . How wonderfully rich must be the universal Silurian fauna ! What a splendid promise to the future explorer ! The 'Thesaurus ' is in the form of a Table . After mentioning the genus ( taken alphabetically ) , its author , and the date of its establishment , the species are successively named , and treated of under four or more heads , along one and the same ruled line . First comes the part of the stage in which it occurs , then , in a given order , its author and locality , or localities , in the column indicative of its proper stage . More information is thus conveyed , it is believed , than by any other form of Table . The summary which is appended to each order shows some of the organic relations of the Silurian system in Europe and in America to each other ; it shows , too , how very little we know as yet of this epoch in Asia and Africa ; and , among other things , it tells us the numerical strength of the genera . Permit me now to lay before the Society a few facts drawn from the mere surface of the ' Thesaurus , ' and only in the way of summary or brief remark , in order to suit the purpose of this evening . Much more than this the careful registration of more than 50,000 facts has prevented me from doing . The Table A ( page 375 ) gives the numerical amount of the Silurian flora and fauna as known in the years 1856 and 1866 respectively . ' Thesaurus Siluricus . TABLE A.-Comparative number of species known in 1856 and 1866 . C ; CsC ; C o , | 0.0 : 0 CS ED 2 ? |idES T'otal . o~a Cs C ) WSL0sXQ Prize Essay 18 19. . 10 63 76 108 93 425 8 5791113 14 151 299 10 9* 1995 Thesaurus ... 1 76 12525 1132 241 1389 496 479 1400 247 14081446 1361 1192 34 6 7553 This Table , taken from Bronn 's Prize Essay published in 1856 , and from the 'Thesaurus Siluricus , ' shows that within the last ten years the number of known species has more than trebled . Universality . In the spirit of the following definition , it would appear that the Silurian system is universal--that is , it overspreads the whble earth more or less completely , and that its component parts were laid down in a proximate time , -statements approved by M. Barrande , Bull . n. s. xii . 361 . Definition:-"A formation may be considered to be universal when it occupies large and small areas in very many parts of the earth , often 'remote from and even antipodal to each other , when it is always of like stratigraphical relations , is composed of like materials , and contains numerous genera in common , together with some representative and some identical species . " In support of our application of this definition to the Silurian system , the 'Thesaurus ' exhibits the widest possible distribution of its fauna-a fauna , it must be remembered , which is pure from admixture with that of any other epoch which might possibly have been progressing at the same time . The 'Thesaurns ' contains many examples of the same species being in twenty to twenty-five different countries , large and far apart the same creature or creatures marking the route from land to land . Table B , drawn up under the inspection of Mr. Salter , presents 195 species common to regions very remote from each other , some of them being antipodal-a fact which tells the more forcibly from the tenacity with which a large part of Silurian life clings to locality as well as to horizon . 179 species are common to Europe and America . Sixty Silurian genera have been brought from South Australia by Mr. Selwyn , the chief Geological Surveyor of that colony ; and Professor McCoy has met with in that country a Siphonotreta , a Phacops , and eighteen species of Graptolites absolutely identical with those of North America andc of Europe . The Professor loudly expresses his surprise and delight . According to M. Barrande , Orthoceras bullatum ( Sowerby ) is at MIelbourne ( Australia ) and in Ireland , Bohemia , Germany , and Russia . Conocoryphe depressa is both in Wales and Texas , one of the American States . Western Tasmania , the *Morris , Catal. p. 362 . Himalayas , Russia , North and South America , and many other regions offer ample fossil evidence of the general presence of the constituents of this period . TABLE B. America America , America Europe Kingdom or Order . No. of and Europo , and and and Total . Species . Europe . Australia . Australia . Australia . Plantso ... ... ... ... 74 Amorphozoa ... ... ... 120 5 ... ... ... ... ... ... 5 Foraminifera ... ... 25 Annelida ... ... ... ... 132 4 ... ... ... ... ... 4 I-Ietero-Pteropoda 239 1 ... ... ... ... ... . . 16 ryozoa. . 383 6365 20 Bryozoa ... ... ... ... 383 6 365 20 Zoophyta ... ... ... 432 18 ... ... ... ... ... . . 18 Crinodea 1 7 ... ... ... ... ... . . 7 Cystidea ... ... ... 456 1 ... ... ... ... ... . . 1 Asteriada J 1 ... ... ... . . Trilobitm ... ... ... . 1414 21 2 ? ... . . 23 Entomostraca ... ... . 242 1 ... ... ... ... ... . . 1 B3rachiopoda ... ... ... 1372 64.4 ... ... ... . 64 Monomyaria ... ... ... 123 2 ... ... ... ... 2 Dimyaria ... ... ... ... 439 9 ... ... ... ... . . 9 Gasteropoda ... ... . . 715 9 ... ... ... . 9 Cephalopoda ... ... ... 955 15 ... ... ... . 15 Pisces ... ... ... ... 34 ... ... ... ... . 7155 179 5 ? ? 65 195 The Silurian beds , it must be borne in mind , are usually visible in mere shreds and remainders , met with in any one place only as a stage or a part of a stage , the other portion being covered for perhaps thousands of square miles by more recent deposits , or removed by denudation ; or it may be that certain stages have never existed , as we see in Arctic America with respect to the Lower Stage ; while in the South , as in Sardinia , France , and Spain , it is the Upper Stage that is wanting , or very nearly so . But the visible geographical spread of these strata is often very great , So extensive are the Silurian areas of North America ( 2000 miles across ) that it only needs a short and easy step to induce a belief in a former universal prevalence and domination of this system . Sufficient territory resting on Silurian rocks has been spared from oscillatory action to enable us to trace it in one or other of its parts over a large part of the earth . Wie follow it circuitously from England to Australia , or to America the interspaces being filled up either by sea , by newer rocks , or by kindred palmozoic strata , which themselves irresistibly bespeak its frequent continuous existence near at hand . This is only a fragment of the argument in favour of the doctrine of Universality of epochs , as just defined . Locality . The 'Thesaurus ' brings conspicuously into view the great influence of ocality on the nature and amount of life , in the same way as we observe at the present time . As each region yields up its fauna to the collector , much of that fauna is found to be new , the bond of connexion with other Silurian districts being in great measure generic . The physical conditions of sea and land being necessarily local , produced as they are from time to time by agencies limited in space , the dwellers among these conditions must in a certain measure be local too , and typical-subject at any moment to removal . The first occupants of any spot who shall point out ? The maximum of life , meaning by that expression the largest combination of abundance , variety , and rank , is local . It may take place at the beginning of a stage , or of an epoch , in the middle , or at the end , being governed principally by the nature of the sediment . The rich Primordial beds of Western Newfoundland and of Quebec , the crowded Pleta beds of Russia and of Esthonia , the Trenton Limestone of America , the Mid-Silurian rocks of Bohemia* ( E. e. 1 , 2 ) , some of those of Wales , the Lower I-Ielderberg group of New York , are conspicuous examples of this . Parts of the Llandovery stage of Wales and of New York ( U. S. A. ) present a great dearth of life , and for a well-known reason . How barren are the vast accumulations of Lower Silurian in Bolivia , as at present believed ! The Potsdam Sandstone of the valleys of the St. Lawrence and the Mississippi shows no signs of life for hundreds ( and perhaps thousands ) of square miles , save in small oases peopled chiefly by Lingulse in incalculable millions of individuals . Nearly equal areas of Central North-east America ( N. latitudes 50 ? -32 ? ) and Europe may have received about the same attention ; but the latter , so far , has proved the richer by above a thousand species , as we see in the subjoined Table C. TABLE C.-Known species of America and Europe compared . Orders . Species . Orders . Species . America . Europe . America . Europe . Plantse ( kingd . ) ... ... ... 56 20 Carried forward ... 964 '931 Amorphozoa ... ... ... ... ... 58 61 Asteriadu ... ... ... ... ... . . 29 29 Foraminifera ... ... ... ... ... . 25 , rt Trilobites 396 1008 Annelida ... ... ... ... ... . 36 98 f Entomlostraca ... 75 170 Ietero-Pteropoda ... ... 96 144 Brachiopoda ... ... ... ... ... 678 721 Polyzoa ( Bryozoa ) ... ... 203 177 Monomyaria ... ... ... ... ... 78 56 Ccelenterata ( Zoophyt . ) 262 245 Dimyaria ... ... ... ... ... . . 181 241 Crinoids ... ... ... ... ... 193 93 Gasteropoda ... ... ... ... 421 274 Cystidea ... ... ... ... ... ... 56 63 Cephalopoda ... ... ... ... ... 321 861 Sedis incerte ... ... ... ... 42 Pisces ... ... ... ... ... ... ... 2 ? ? 34 964 931 3145 4325 The Cephalopoda , Crustacea , Brachiopoda , and Annelida of Europe appear to largely exceed in number of species those of North America , while in nine Orders ( see Table C ) the two hemispheres hold nearly equal quantities . America greatly surpasses Europe in the number of its Crinoids , and to a smaller extent in Plantse and Gasteropoda . I am not prepared with any inference from these facts . We know that the mineral constitution , and the past externalI influences in these several parts of the earth are different-not that the first is as influential as has been supposed . Many species are marked as undefined in the ' Thesaurus , ' because they are often only known by simple fragments . About a thousand species have never been seen but in one locality . At least 200 Cyrtocerata are huddled together in the two contiguous parishes of Lockhov and Kozorz , near Prague , and , with other mollusks there , are unknown elsewhere . Other instances of this might be cited . The two Silurian districts of Sardinia , with not a few fossils in common with Spain , although tolerably well examined by La Marmora and MBeneghini , have not hitherto produced a Trilobite ; nor has Spain given up a Pentamerus , as far as can be learnt . Out of our sixty species of AsapAus only one is known in Bohemia . Silurian fish are only mentioned as existing in Britain , Bohemia , and Russia ; but doubtless they are in other Silurian areas . The Trilobite genus Diielocephahls of D. D. Owen contains thirty species . Only three are found in two places . Twelve species are near Quebec , and there only . Nine others are Minnesotan , on the Upper Mississippi ; while the States of Texas and Vermont , on Lake Champlain , have each one , and Wales three-all distinct species . Western Newfoundland , although primordial , is thought to be without this remarkable genus . Each of the twenty-seven known species of the Heteropod Maclurea is confined to one spot ; twenty are American ; and of these , eleven are confined to Newfoundland West . Of the forty-five species of the genus Trochoceras ( Cephalopoda ) , fortythree are restricted to the vicinity of Prague ; and of these twenty-seven inhabited the very small space of 4-6 square miles , in company with many other mollusks . The Brachiopoda of Bohemia are mostly in the Fauna F , and in the two small districts of Konieprus and Mnienian . Out of 270 species of Orthis only two are believed to be in Nova Scotia , and of the 109 species of the Gasteropod Murchisonia , again , two , but not one of the elsewhere most abundant genus Pleurotomaria . On the other hand , Nova Scotia holds onerhalf of all our Cleidophora ; and Tasmania is singularly rich in Palhearca , while the Point Levi shales are crowded with the Graptolite family , of extreme beauty , and rarely found in other countries . We further observe that , as it is with the horizontal disposition of Silurian life , so it is with the vertical : only twelve per cent. leave their native horizon , as we shall see . hese few facts have been selected from many , to show the strong tendency to localization inherent in the Silurian fauna . Primordial Stage . The ' Thesaurus ' amply manifests the great extent of this stage , and the high significance of its teachings ; but we shall here only speak of a few leading facts relating to Canada , extracted from the 'Thesaurus ' itself . While waiting for the results of field-work now in progress , Mr. Billings has treated this subject with his usual great ability in the first volume of the work entitled ' The Palaeozoic Fossils of Canada . ' The Primordial stage of Barranlde ( Taconic of Emmons ) is truly Silurian , and forms the base of that epoch . In the valley of the St. Lawrence it may average 8600 feet in thickness . Resting horizontally in America on the inclined Laurentian rocks , the lower break is complete in every respect ; while the upper break is very nearly so , although purely organic . It divides naturally into Lower and Upper Primordial , -Potsdam sandstone constituting the former , and calciferous sandstone , with the enigmatical Quebec group , the latter , with a few layers of chazy limestone superadded . The whole flora and fauna of the Primordial stage , American and European , amount to 919 species , while those of the St. Lawrence Valley alone are 560 . The western , therefore , seems to be the richer of the two hemispheres ; and this comes out still more distinctly in stating the fact that the Primordial genera at present known in America are 134 , and those of all Europe 83 . Table D ( below ) has been constructed from the ' Thesaurus . ' It exhibits numerically the zoological contents and the zoological relations of the several parts of the Primordial stage ; and we see that the differences are great . TABLE D.-The American Flora and Fauna of the Primordial Stage ( principally Canadian). . 1 ? ? ; 's4 _--_mI___ __l I__ __ , _ __ f Quebec Group ... ... ... 421 1944 2 ... ... ... . 5 57 42 34 96 3 ... 327 UPpER. . CalciferousSandst ... . 653 5 ... ... . 1..39 61 62 ? ? 93 LowR Potsdam Sandstone ... 16 ? ? 242 1 ... ... ... l ? 2421 ... . . 74 6 ... .140 Total ... ... ... . 22 11 28 2645 3 ... ... 6 ... 7953 176ll11 o 6C Great interest attaches to every part of this stage , but especially to the Quebec group and its ill-understood connexion with the immediately contiguous strata . An intimate acquaintance with this group near Quebec leads me to believe that there , at least , it is a displaced , crumpled , and fractured mass of schist , with thin beds of limestone and calcareous conglomerate interleaved , the last crowded with molluscan and crustacean life . It is above the Potsdam Sandstone , and on or near the horizon of Calciferous sandstone and the lower layers of Chazy Limestone ( Logan and Billings , Report , 1863 ) . Into these ( with a distinct tendency still higher ) in other parts of North America , the Quebec group probably becomes fised , and assumes their horizontal position , mineral character , and many of their organic contents . The fauna of the Quebec group , consisting of 327 species at Point Levi ( Quebec ) and in Western Newfoundland , is peculiar , and , of course , is only found there , with the exception of thirteen species found elsewhere in Calciferous sandstone , and eight in Chazy Limestone . They are one-sixteenth of the whole , and are as follows : Calciferous Sandstone:-Lingulc Mantelli , Z. acuminata , L. Irene , Camreralla calcifera , IIelicotoma gorgonia , H. uniangulata , II . perstriata , Pleurotomaria calcifera , P. postzmnia , LHolopcea dilucula ? , Ecculionphalus Cancadensis , 3lurchisonia Anna , Piloceras Canadense ( Billings ) . Chazy Limestone:-Eculiom3phalus Atlanticus , Maclurea Atlantica , Stromatopora compacta ( running into B+ BL ) , Clinacogr aptus antennarius , Ptilodictya fenestrata ? , Leperditia amygdalina , Camerella varians , Cheirurus prolifcus ( Billings ) . " This group contains , besides the thirteen species just enumerated , 174 allied to those of the Calciferous Sandstone of Central North America , or more or less westward of Montreal . It is this which connects it closely with the sandstone . However , 140 remain typical . The fossils of Chazy Limestone met with in the Quebec group only belong to a few of the basement beds of the former , because these almost immediately , upwards , [ change into a compact mass of crushed Crinoids , Cephalopoda , Gasteropoda , &c. ( 143 species)-all quite new , and alien from the life below . The Calciferous Sandstone , always truly primordial , has in the Canadas and the United States of America 375 species , overspreading vast areas . They may be separated into three sets:1 . Thirteen enter the Quebec group . 2 . One hundred and seventy-four are the allies of that group . 3 . One hundred and eighty-eight are foreign to it , and for the most part typical . Like its two sister groups , the Calciferous Sandstone is shown , in the middle line of Table D , to display a remarkable tendency to abound in complex and powerful existences , and to paucity in the simple species , in. . These numbers aee for tl ? e present only approximate , and may be altered . TABLE E.-A synoptical view of Silurian Life , with special reference to vertical Range or Recurrence . Primordial Silurian . Lower . Upper . Plantee ... ... ... ... ... ... ... Amorphozoa ... ... ... ... ... Annelida ... ... ... ... ... ... . Hetero-Pte ro poda ... ... ... Polyzoa ... ... ... ... ... ... ... Ccelenterata ... ... ... ... ... Crinoidea ... ... ... ... ... ... Cystidea ... ... ... ... ... ... ... Asteriada ... ... ... ... ... ... Trilobite ... ... ... ... ... ... Entomostraca ... ... ... ... Brachiopoda : Orthis ... Rhynchonella ... ... Strophomena ... . all other Species ... Monomyaria ... ... ... ... ... Dimyaria ... ... ... ... ... ... Gaster . : Murchisonia ... Pleurotomaria ... ... all other Species ... Cephkal . : Gomphoceras ... Cyrtoceras ... ... ... ... Orthoceras ... ... ... all other Species ... 14 4 10 84 178 11 8 ... 40 1 5 ... ... 67 22 51 2 . i1 162 9 17 12 30 5 15 18 30 7 25 13 Species typical of one Horizon . Lower Silurian . 37 56 34 98 149 97 99 64 24 538 55 113 20 29 216 27 211 37 56 171 4 36 128 111 Middle Silurian . 17 789 26 35 10 24 43 4 12 22 9 80 5 25 6 11 23 58 225 96 105 Upper Silurian . 5 25 26 38 64 179 132 31 21 264 115 56 73 15 299 70 127 26 20 131 16 35 95 fCq Total ( typic . ) 73 98 85 175 294 313 241 98 50 1185 194 206 116 55 665 102 369 84 106 360 78 303 344 298 284 ' 424 3010 624 1931 5891 Grand ' Total H2 82 4 110 ... 99 ... 212 3 333 . 384 . 267 ... 101 1 54 ... 1331 3 205 ... 243 . 141 . 80 ... 759 ... 121 ... 426 ... 105 ... 125 ... 389..82 ... 312 . 409 ... 321. . I. . 6611 Primordial . Lower . Upper . lorizons . Horizons II 314 512l3 4 ... { . 1 . I. . , ,..t ... . ! ... ... ... ... . i ! . it ''..1 ... ... 1 ... ... iii ii ' I ' ili iii *''- ... ... ... ..''- ' 4 ... 7 4. . Species Recurrent . Lower Silurian . Horizons . 52 13 415 4 1 ... ' ... 6 4 ... 41 4 ... ... 21 1 4 ... ... 17 911 30 13 8. . 13 1 ... ... 13a1 ... ... 1 1 ... . 2 ... 1 ... ... 69 15 5 2 ... ..4 1 ... ... . . 21 81 1. . 7 2 ... 7 ... 2 ... . . 24 1.34 1 ... 5 31 ... . . 15 ... ... ... 29 61 ... ... 15 ... ... . 12 1 ... 2 12 i ... ... ... 7 ... ... ... . . 28 10i 5 ... ... 11 112 ... 1 384 19344 5 ! [ l IMiddle Silurian . Horizons . 2134 15.I. . 2.1 2 . : 2 : : 1 . 2 . 3 i ? I. 3 . 3. . i , : 36 12 3 14 22 10 38I721 95 293 I ... Upper m Silurian . Horizons . fP 23 14 i 1 ... L ... *9 11 1 ... ... ... 12 11 2 1 . 14 15 13 I ... ... . 37 16 1 ... ... . . 39 11 5. . 71 20 7 ... ... ... 26 10 ... ... . 1 ... ... 49 27 3 2 ... 146 11 2 ... ... . 11 52 1 ... ... 37 84 1 ... 25 27 4 ... 1 ... 25 31 19 6 ... . . 94 12 6 ... ... . . 19 16 10 2 ... . 57 13 4 ... ... . 21 20 1 1 ... . 19 17 ... ... . . 37 2 ... ... i ... 45 9 ... ... ... 93 14 ... I. . 6616 129 15 3 ... 801 12. . l 'C-1 . _ , 00 II r o. i dividuals , nevertheless , being prodigiously numerous . Trilobites are here very few . Potsdam Sandstone is rich " in Trilobites , Brachiopoda , and Fucoids , but in every other form is very poor ; and yet it possesses a Cystid . In the Primordial group , therefore , we find numerous representatives of nearly every marine Invertebrate ; and we have a startling example of the sudden development in very early times of the highest types of molluscan life , Nautili , Lituites , Trilobites , Protichnites , &c. , dwelling , even then , in well adjusted communities . Most of these facts are taken from the ' Thesaurus ; ' but this interesting portion of the 'Thesaurus ' itself is the gift of Barrande , Emmons , Hall , Logan , and Billings * , and is the fruit of their unwearied study in the city , and of their toil in the field . Recurrence . A few words on the subject of recurrence , or the vertical range of Silurian life . What can be more unexpected , or more wonderful , than the upward passage by a filial succession , through stages and epochs , of a mollusk during centuries inconceivably numerous ! What an almost interminable series of posterities must have followed the first ancestor ! The doctrine of limited duration in species must have its exceptions . The 'Thesaurus ' enumerates 803 recurrents , or 12 per cent. of the whole known life of the epoch-a very notable proportion , -still leaving 6200 species faithful to one horizon . The synoptical Table E , compiled from the 'Thesaurus , ' exhibits many details , and may be trusted approximately , although about 400 species have been passed by for want of sufficient information . It numbers sepa . rately the species typical of one horizon , and the species frequenting more than one horizon ( being recurrent ) . It also introduces some of the greater genera , such as Orthis , Murchisonia , &c. The species are arranged under the heads " Primordial , " Lower , " " Middle , " and " Upper Silurian ; " and in the case of the recurrents the number of horizons occupied by them is shown by the figures 2 , 3 , 4 , 5 . Thus we find that 69 Lower Silurian Trilobites occupy two horizons , 15 three , and 2 five horizons . The percentage is stated in the last column , next to that containing the total recurrence of each order . The Primordial stage only gives 27 per cent. of recurrency . The Lower Silurian ... ... . . 16 , , The Middle ... ... ... ... 20 , The Upper ... ... ... ... 8 , , The orders vary greatly in respect to recurrency . There is none among fossil fish . In Cystidea it is only 3 per cent. , in Gomphoceras 5 per cent. , and is greatest in Strophomena , 31 per cent. Although a considerable number of inferences have been prepared , I shall only venture now to introduce a few . 1 . Recurrence is universal , both as to time and place . 2 . Recurrences seem to be most numerous in the lower stages of the epoch ; but further research may teach otherwise . 3 . Species do not often change their horizon , not even when placed in countries far apart . 4 . The same species may be typical of a single horizon in one country and recurrent in another . 5 . Recurrency shows that a mollusk is not necessarily confined to any one community , but may find a home and flourish in several successively . t6 . The number of recurrents measures the amount of change in conditions . 7 . Communities , genera , and species disappear sporadically , except in the rare case of a catastrophe . 8 . Recurrency is a measure of viability . Extra-epochal Recurrence . Few things demonstrate more plainly the sterner discipline now prevailing than the reduction by Mr. Salter to 133 of the 439 palEeozoic species which I had tabulated as extra-epochal , although they had the sanction of the best palaeontologists of the last fifteen or twenty years . My Table , as originally made out , deals with the five palaeozoic epochs , but in this place only with the forty-two Silurian species which leave for the higher periods . To these , recently , several interesting additions have been made . I. These recurrents are mostly distinct from the intra-epochal , owing to their first appearance being in the Upper Silurian stage . II . With the exception of Chonetes sarcinulata , they all stop within the Devonian Period . III . The greater part of these recurrents are of low rank ; 20 are Brachiopoda ; 11 Zoophytes , 1 an Amorphozoa ; 7 are Gasteropoda ; 3 Cepllalopoda ; and 1 Trilobite . Ml/ anon deform and Orthis rugosa , Lower Silurian fossils , reappear in Devonian , but not in Upper Silurian , where they are " presumably " -to use an expression of Mr. Etheridge . IV . These species are very migratory-few being found in two epochs in the same country , but in different countries . V. Opportunities of escape into a new epoch have been common ; but the ways and means are frequently concealed by denudations , &c. VI . Acclimatization must have been necessary . VII . The length of individual life in proportion to specific extraepochal life is almost as a unit to infinity . 1867 . ] I TZhesaurus Siluricus . ' 383 ' Thesaurus Siluricus . ' [ Feb. 21 , TABLE F.-Geographical Summary of Silurian Life . R~hiz opoda ... ... ... ... ... ... . . 25 ? ... ... . . ot deefinitely accepted ... ... ... ... ... . 22 245 1 ... 21 27 To Aerica and urop . ( Crinoidea ... Pn Cysti ... ... ... ... ... ... 56 ... . Tibet , Amonrphozoa ... ... ... ... ... 62 63 4'^. . 116 To America and Europe . Asodia ... ... ... ... ... 2 ... ... ... ... accepted . Clenterata ... ... ... ... 262 245 121 27 To America and Europe . X Cystidea . 56 53 . 20 3 . ^ Asteriaca . 29 29 ... ... . 1 Annelida ... ... ... ... ... . . 36 98 ... ... 1 ... 7 fTrilobitm ... ... ... 396 998 10 ... 11 ... 30 Various . Phyllopoda 1 77 170 ... ... 2 ... 50 Ostracoda J ... 7 Polyzoa ... ... ... ... ... ... . 203 177 2 ... 20 ... 23 Various . Brachiopoda ... ... ... ... ... 678 721 22 ... 19 ... 65 Various . Monomyaria ... ... ... ... ... 78 56 ... ... 25 To America and Europe . Dimyaria ... ... ... ... ... ... 181 241 3 ... 8 19 12 Pteropoda & Heteropoda 103 145 1 ... 31 15 . Gasteropoda ... ... ... ... ... 421 274 9 ... 9 13 10 . Cephalopoda ... ... ... ... ... 321 861 5 ... ... 8 16 . Pisces ... ... ... ... ... ... ... ... 34 Incertn Sedis ... ... ... ... . . 4 2 ... ... ... ... ... 31564305 57 ... 100 43 231 3156+4305=7461 species . Geographical Distribution of Silurian Life . The 'Thesaurus ' tends to show that North America , east of the Riocky Mountains , may probably be divided into two areas , the one to the north of 57 ? ( or of Lake Superior ) being chiefly Upper Silurian , resting on crystalline rocks , the one to the south of that line , down to the Gulf of Mexico , on the contrary , being fully developed in some part of this great space . It exhibits the regrettable fact that Asia , Africa , and Australia , taken together , have hitherto yielded only 200 species of Silurian remains ; but this arises from the absence of exploration . I have not yet had opportunity to bring together , harmonize , and compare the Silurian life of the several countries of Europe . The accomplishment of such a task might produce some definite truths , and many more probabilities . Either this vast region would prove to be one great Silurian area , with barriers here and there , and with certain channels of communication , and to be the result of many operations throughout a long interval of time ; or it might turn out that the Silurian deposits and their fossils occupy three separate areas:-(1 ) the Britanno-Scandinavian , which has all the three stages , and the Primordial ; ( 2 ) the Bohemian , at present of peculiar interest ; and ( 3 ) the middle and southern area , found in France , Spain , and Sardinia , almost wholly Lower and Mid-Silurian . Under this head of geographical distribution we have to deal with some curious phenomena-such as concern birthplace or first appearance , generic and specific , the duration of life , tolerance of conditions , mineral habitats . Migration possesses great interest , with its marks , causes , and modes , with its power , direction , and rate of progress , &c. The transport or removal of dead organic matter from place to place , the " remaniement " of French geologists , is an important agency under several aspects , especially in the formation of extensive sheets of rock . It now has become proper to bring to a close these few observations , or rather this enumeration of heads of Natural-History subjects , by express ing a confident hope that this compilation will find many and well qualified interpreters , and will be useful to geologists in general .
112655
3701662
On a Transit-Instrument and a Zenith Sector, to Be Used on the Great Trigonometrical Survey of India for the Determination, Respectively, of Longitude and Latitude
385
387
1,866
15
Proceedings of the Royal Society of London
A. Strange
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0085
null
proceedings
1,860
1,850
1,800
3
52
1,032
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112655
10.1098/rspl.1866.0085
http://www.jstor.org/stable/112655
null
null
Measurement
45.238059
Astronomy
35.263386
Measurement
[ 61.782901763916016, 17.64299964904785 ]
I. " On a Transit-Instrument and a Zenith Sector , to be used on the Great Trigonometrical Survey of India for the determination , respectively , of Longitude and Latitude . " By Lieut.-Colonel A. STRANGE , F.R.S. Received February 16 , 1867 . In 1862 the Secretary of State for India in Council sanctioned the provision of an extensive equipment of geodesical and astronomical instruments of the first order for the use of the Great Trigonometrical Survey of India ; and he did me the honour to entrust to me the task of designing and superintending their construction . After several modifications , the following list was adopted : One GREAT THEODOLITE , with a 3-feet Horizontal Circle . By Messrs. Troughton and Simms . Two ZENITH SECTORS . By Messrs. Troughton and Simms . Two 5-FEET TRANSIT-INSTRUMVENTS . By Messrs. T. Cooke and Sons , York . Two SMALLER TRANSIT-INSTRUMENTS ( German form ) . By Messrs. T. Cooke and Sons , York . Two 12-INCH VERTICAL CIrCLES ( German form ) . By Messrs. Iepsold , Hamburg . Two GALVANIC CIHRONOGRAPRS for registering Transit-Observations . By MM . Secretan and Hardy , Paris . Three ASTRONOMICAL CLOCKS . -By Mr. Charles Frodsham . The whole of these are nearly ready , and I take the opportunity of now submitting two of them ( a 5-feet transit-instrument by Messrs , Cooke , and a zenith sector by Messrs. Troughton and Simms ) to the inspection of the Royal Society . Both instruments present peculiarities . The 5-feet Transit-Instrument.-This has a very powerful telescope of 5 inches clear aperture ( a large diameter in proportion to its focal length ) . The axis is of aluminium bronze , cast in one piece , hollow , and turned both inside and out . The two halves of the telescope are easily separable from the axis for portability . It is provided with four levels for rendering the axis horizontal ; these are mounted on a plan suggested and devised by Mr. Cooke . He remarks that the ordinary striding level usually applied to such instruments watches the pivots only , whereas the observer wishes to be informed whether or not the telescope itself describes a true plane . This it will not do if the flexure of the axis differs , as it may do , in different altitudes . Mr. Cooke therefore attaches the levels to the telescope . His mode of doing this , and of providing for their due adjustment , will , in the absence of drawings , be best understood by inspecting the instrument . The means of adjusting the axis vertically and azimuthally are also peculiar . The bearings on which the pivots turn are carried by strong threearmed pieces , similar in form to the tribrach of an ordinary theodolite . On one side the tribrach is raised or lowered by means of the three vertical screws which form its feet , and the axis is thus made horizontal ; on the other side the tribrach is pushed laterally by two horizontal screws , and the telescope is thus brought into the meridian . Three principal objects are sought in these arrangements--to exclude shake , to obviate strain , and to cause the expansions to take place from the centre outwards . I have been well satisfied with the trials I have made of them . I find these adjustments to be exceedingly delicate in their action , and very stable . The Zenith Sector.-This is quite unlike any instrument of the same denomination . My endeavour in designing it was to combine maximum power with minimum weight . A solid steel vertical axis revolves within a hollow wide-based conical cast-iron pillar . Across the vertical axis is placed a frame , in which are formed bearings for the reception of a transverse horizontal axis . This axis carries outside the frame a telescope of 4 feet focal length and 4 inches clear aperture , and a portion of a circle comprising two opposite sectors , each containing about 45 ? . The telescope being vertical for the observation of stars near the zenith , the sectors are horizontal-that is , transverse to the telescope . The frame which supports the horizontal axis carries also four micrometer-microscopes for reading the sectors . These microscopes are arranged conically , so that all four are illuminated by a single light , in the manner adopted by the Astronomer Royal for the Great Greenwich Transit-Circle . The telescope and sectors revolve together , the microscopes being fixed . When packed for carriage , the telescope and sectors can be made to lie in the same direction , and so take up much less room than if they retained their transversal positions . Two levels are fixed to the horizontal-axis frame . The instrument is duly counterpoised . The general arrangement of the instrument may be best conceived by supposing an equatoreal of the German form to be adjusted as it would be at the pole , when its polar axis would represent the vertical axis of the zenith sector , and its declination axis the horizontal axis . The instrument has been too short a time in my hands to admit of my forming an opinion as to its probable success . I anticipate some advantage from the arrangement of the sectors , which , being in identical circumstances , should be liable to no inequalities of either flexure or temperature . Both of the principal axes of the instruments are provided with independent adjustments , the action of which appears to be very satisfactory . In concluding this brief and imperfect notice , I beg to state that I hope to draw up hereafter a full and detailed description of all the instruments given in the foregoing list . At present my time is absorbed by the trials and experiments to which it is necessary that I should subject them before their despatch to India ; and I trust the Royal Society will accept this explanation as an excuse for the meagreness of the present account .
112656
3701662
On the Orders and Genera of Ternary Quadratic Forms. [Abstract]
387
389
1,866
15
Proceedings of the Royal Society of London
Henry J. Stephen Smith
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
3
47
1,375
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112656
null
http://www.jstor.org/stable/112656
null
108,976
Formulae
85.116131
Tables
7.74022
Mathematics
[ 71.7104263305664, -31.991230010986328 ]
II . " On the Orders and Genera of Ternary Quadratic Forms . " By HENRY J. STEPHEN SMITH , M.A. , F.R.S. , Savilian Professor of Geometry in the University of Oxford . Received February 21 , 1867 . ( Abstract . ) The object of this Paper is to supply demonstrations of the undemonstrated results , relating to Ternary Quadratic Forms , which are contained in an important memoir of Eisenstein 's ( " Never Theoreme der hoheren Arithmetik , " Crelle 's Journal , vol. xxxv . p. 117 ) , and , at the same time , to extend those results to the cases not considered by him in that Memoir . The following are the principal points in which the theory of Eisenstein has been thus further developed:1 . In Eisenstein 's Memoir forms of an even discriminant only are considered . Such forms , and their contravariants , are always properly primitive ; they have particular generic characters with respect to uneven primes dividing the discriminant , but have no supplementary characters ( i. e. characters with respect to 4 or 8 ) . The case of forms of an even discriminant is more complicated . Besides the properly primitive order , there may exist , in this case , an improperly primitive order , in which the forms themselves are improperly primitive , and their contravariants properly primitive , -or , again , an improperly primitive order , in which the forms themselves are properly primitive , and their contravariants improperly primitive . Further , forms of an even discriminant may have characters with respect to 4 or 8 ; and a complete enumeration of these supplementary characters requires a carefill distinction of cases . To facilitate this enu meration , a Table is given in the Paper for finding the supplementary characters of any proposed form . 2 . A Table is also given for forming the complete generic character of any proposed form . This Table is intended to serve the same purposes , in the theory of ternary quadratic forms , for which the Table of Lejeune Dirichlet is available in the binary theory ( Crelle , vol. xix . p. 338 ) . The Table , like that of Lejeune Dirichlet , distinguishes between the possible and impossible generic characters ; and the Paper contains a complete demonstration of the criterion by which they are distinguished . 3 . Besides the particular characters relating to uneven primes dividing the discriminant , it is convenient , in those cases in which there is no supplementary character , to consider a certain particular generic character which does not appear to have been regarded as such by Eisenstein . This character is termed in the Paper the simultaneous character of the form and its contravariant : its existence is demonstrated ; and its introduction as an element of the complete generic character is justified by its use in the distinction of possible and impossible genera . 4 . It has been proposed to define a genus of forms as consisting of all those forms which can be transformed into one another by substitutions of which the coefficients are rational and the determinant a unit . It is desirable ( in the case of quadratic forms ) to add to this definition the limitation that the denominators of the fractional coefficients are to be uneven , and prime to the discriminant . And it is shown , in this Paper , that two ternary quadratic forms are or are not transformable into one another by such substitutions , according as their complete generic characters do or do not coincide . 5 . The preceding observations apply equally to the cases of definite and indefinite forms . These two cases are included in the same analysis by means of a convention as to the signs of the two numbers defined by Eisenstein , and termed in this Paper the arithmetical invariants of the ternary form . The first invariant of a form is the greatest common divisor of the first minors of the matrix of the form ; the second invariant is the quotient obtained by dividing the discriminant by the square of the first invariant . According to the convention adopted in the Paper , the second invariant has the same sign as the discriminant ; and the first invariant has or has not the same sign as the second , according as the form is definite or indefinite . 6 . The latter part of the Paper is occupied exclusively with ; he theory of definite and positive forms . In the case of these forms , the weight ( or , as Eisenstein has termed it , the density ) of a class is the reciprocal of the number of automorphics ( of determinant +1 ) of any form of the class ; the weight of a representation of a number by a form is the weight of the form , i. e. the weight of the class containing the form ; the weight of a genus or order is the sum of the weights of the classes comprised in the genus or order . In his Memoir , Eisenstein has given ( but without demonstration ) the formulae which assign the weight of a given genus or order of forms of an uneven discriminant . These formulae are demonstrated in the present Paper , and , with them , the corresponding formula relating to the cases in which the discriminant is even . The demonstration is obtained by a method similar to that employed by Gauss and Dirichlet for the determination of the number of binary classes of a given determinant . The sum of the weights of the representations , by a system of forms representing the classes of any proposed genus , of all the numbers contained in certain arithmetical progressions , and not surpassing a given number , is in a finite ratio to the sesquiplicate power of the given number when that number is supposed to increase without limit . Of this limiting ratio , two distinct determinations are obtained ; of which the first contains , as a factor , the weight of the proposed genus ; and an expression for that weight is obtained by a comparison of the two determinations . Of these determinations , the first is obtained immediately by an elementary application of the integral calculus ; the second depends on an arithmetical theorem , which is deduced in the Paper from the analysis employed by Gauss in arts . 279-284 of the ' Disquisitiones Arithmeticae , ' and which may be expressed as follows:"The sum of the weights of the representations of a given number ( contained in one of certain Arithmetical Progressions ) by a system of forms representing the classes of a ternary genus , is equal to the weight of a genus of binary forms , of which the determinant is the product , taken negatively , of the given number by the second invariant of the ternary forms . " By this proposition the determination of the limiting ratio is made to depend on an approximate determination of the weight ( or , which is here the same thing , the number ) of the binary classes of certain series of negative determinants . Two methods are given in the Paper for effecting this approximate determination . The first method presupposes Lagrange 's definition of a reduced form , and depends ultimately on the evaluation of the definite integral fff ( z-y ) dx die dzof which the limits are given by the inequalities ? '0 , y > o , z > 0 , < Oz , 2y-Ke The second inethod employs the expression obtained by Lejeune Dirichlet in the form of an infinite series for the number of binary classes of a given determinant , and is thus independent of the definition of a reduced form . The same result is obtained by both methods ; but the second is more easily extended to the case of quadratic forms containing more than three indeterminates . V'OL , XV .
112657
3701662
Croonian Lecture for 1867: On the Influence Exerted by the Movements of Respiration on the Circulation of the Blood. [Abstract]
390
396
1,866
15
Proceedings of the Royal Society of London
J. Burdon Sanderson
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
6
88
2,992
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112657
null
http://www.jstor.org/stable/112657
null
null
Nervous System
32.913183
Biology 2
25.572699
Nervous System
[ -65.25092315673828, -1.3920916318893433 ]
" On the Influence exerted by the Movements of Respiration on the Circulation of the Blood . " Being the CROONIAN LECTURE for 1867 , delivered by Dr. J. BURDON SANDERSON . ( Abstract ) . The purpose of the lecture was to show that the explanation usually given by physiologists of the mode in which the respiratory movements of the thorax influence the force and frequency of the contractions of the heart can no longer be entertained . The doctrine usually taught in this and other countries is stated as follows in one of the most recent text-books:- " During the act of expiration the frequency of the pulse is considerably augmented , whilst the line of mean pressure rapidly rises , indicating increased tension in the arterial walls ... ... During the act of inspiration , on the contrary , the pulsation becomes slower , the curves much bolder , and the line of mean pressure gradually falls ; for then the blood readily enters the thorax , and , as a consequence , the great veins , capillaries , and arterial walls become comparatively flaccid " ( Carpenter 's 'Physiology , ' 1864 , p. 345 ) . Statements to the same effect are to be found in Budge 's 'Lehrbuch der Physiologic , ' 1862 , p. 350 ; in Kirke 's 'Handbook of Physiology , ' 1863 , p. 129 ; in Ludwig 's 'Lehrbuch , ' 1857 , vol. ii . pp. 161 , 162 . From numerous experiments , in which the respiratory movements and the variation of pressure in the arteries in the dog were recorded simultaneously by mechanical means , the author had arrived at an opposite conclusion , viz. that in natural breathing each expansion of the chest is followed by increase of arterial tension and shortening of the diastolic interval ; in other words , that the immediate effect of inspiration is to increase both the force and frequency of the contractions of the heart . The experimental metl-od was as follows:-For the purpose of recording the movement of air in and out of the chest , the animal is caused to breathe through a T-shaped tube , one arm of which is connected with the trachea , while the other remains open . By the stem it communicates with a diskshaped bag of thin caoutchouc . The resistance afforded to the ingress and egress of air by the tube , although very inconsiderable , is yet sufficient to produce alternate movements of expansion and collapse of the bag . The variations of arterial pressure are measured by a mercurial manometer , differing from that of Poiseuille , in that the attached arm , which is the longer of the two , is of much smaller diameter than the other , the area of the latter being twelve times as great as that of the former . For the purpose of recording the movements of the dynamometer and of the caoutchouc bag , two light wooden levers of the third kind , each 25 inches in length , are used . These work on steel axes , the bearings of which are so contrived that the axis of the arterial lever is directly above that of the respiratory lever , and that both oscillate in the same vertical plane : by vertical rods they are connected , the upper or arterial lever with a cork float 2 which rests on the surface of the mercury in the wide arm of the dynamometer , the lower with the upper surface of the caoutchouc bag . At their extremities they carry fine sable brushes , by which their movements are inscribed on a roll of paper , to which a horizontal movement is communicated by clockwork . By a mechanical arrangement , which need not be here described , synchronical points can from time to time be marked in the two tracings inscribed simultaneously on the paper by the momentary withdrawal of both brushes . The experiments were of the following nature , dogs being employed throughout . 1 . Experiments as to normal respiration . In these experiments ( eleven in number ) the dynamometer was connected with the femoral artery , while the breathing-tube was connected with the respiratory cavity , either by the trachea , or by means of a mask fixed over the snout . The principal results were as follows : Experiment 1.-Respirations per minute , 9 ; pulsations , 108 . Mean arterial pressure 6-2 inches . The tracings show that each respiratory act is divisible into two parts ; two-fifths being occupied by thoracic movements , the remainder by the pause . Of the former , two-thirds correspond to inspiration , one-third to expiration . During the pause the arterial pressure gradually sinks , the commencement of inspiration being immediately followed by an increase of pressure , which becomes still more marked during expiration , but again subsides at its completion . The interval between each two succeeding contractions of the heart is seen to be three times as great in those pulsations which immediatelyfollow expiration as in those which precede it . The other experiments of the series were of a similar nature . In some the relative length of the respiratory intervals and the regularity of the pulsations rendered it more easy to judge of the precise relation between the two tracings than in others , but in all the results were in complete accordance with those above stated . Even when the frequency of breathing was such that three pulsations corresponded to one respiration ( experiment 4 ) , it was observed that the diastolic interval which immediately followed expiration was twice as long as either of the other two . In one case the respiratory tracing showed that the mode of breathing was peculiar : inspiration was separated from expiration by a pause of considerable duration , during which the arterial pressure declined and the pulse was retarded . 2 . Experiments for the purpose of determining whetler the resistance aforded by the T-tube to the passage of air in and out of the chest exercise any modifying influence on the results.-It was obvious that this end could be best attained by observing the effect of increasing the resistance ; for by so doing , any modifying influence exercised by it would become more obvious . With this view a series of observations were made on the same animal ( under the influence of morphia ) , in which the resistance was gradually increased by inserting plugs of various sizes into the aperture of the T-tube . The tracings showed that even when the aperture was So diminished as to produce marked dyspnoea , and great exaggeration of the movements of respiration , it was observed as distinctly as before that the increase of force and frequency of the pulse were increased by the prolonged inspiratory efforts of the animal . 3 . Experiments showing that when the respiratory cavity is completely closed ( as by plugging the trachea ) , the relation between the respiratory movements of the chest and the arterial pressure is reversed.-The process of death by apncea may be divided into two stages ; the first extending from the moment of occlusion to the cessation of the struggles of the animal and the supervention of apparent insensibility , the second terminating with the extinction of the circulation . In order to observe the characters of the respiratory movements and those of the heart during these two stages , it was necessary to substitute a mercurial manometer for the caoutchouc bag . It was then seen that at first the respiratory movements increase in amplitude without altering in character ; but towards the end of the first minute , when the animal begins to struggle , they become irregular , and each struggle is accompanied by strong expulsive efforts , during which the mercury in the dynamometer oscillates violently and rises to an enormous height . At the commencement of the second stage , when the animal becomes tranquil , the respiratory movements assume a different character , become almost exclusively inspiratory ( gasping ) , and much more regular . They occur , however , at longer and longer intervals , until they finally cease . As regards the relation between the oscillations of the two manometers , the tracings show distinctly that throughout the whole process they are strictly coincident , both as to the time of their occurrence and their extent . Ience it may be concluded that the extraordinary elevation of arterial pressure which has been long known to occur during the second minute in death by apncea , is not due , as was supposed by Dr. Alison and Dr. John Reid , to obstruction of the capillary vessels , either pulmonary or systemic , but to the violence of the respiratory efforts . The cavity of the chest being closed , the force exercised by the respiratory muscles expresses itself in variations of tension of the enclosed air , which are communicated through the intra-thoracic arteries to those outside of the chest , producing those violent oscillations of the dynamometer which have been referred to . In support of this inference , it was shown that in an animal under the influence of woorara ( when all respiratory movement ceases , while those of the heart are unaffected ) , the process of apncea is not only of greater duration , but is not attended with any of those peculiar disturbances of the circulation which have been hitherto attributed to capillary obstruction . The gradual extinction of the force of the contraction of the heart is indicated by a slow and uninterrupted subsidence of the arterial pressure . 4 . Experiments for the purpose of ascertaining in how far the influence exercised by the respiratory movements on the heart in ordinary breathing are chemical.-For this purpose observations were made on animals which had been allowed to respire a limited quantity of air ( 50-100 cubic inches ) for a sufficiently long time to enshre the complete cessation of all appreciable reaction of its oxygen on the circulating blood . In this form of apncea insensibility is not produced until from ten to fifteen minutes after the experiment . As in ordinary suffocation , it is associated with a marked change in the mode of breathing . All expiratory efforts cease , and the animal respires by gasps , each of which is separated from its successor by a pause of variable duration . Under these circumstances , when unquestionably all chemical reaction is out of the question , the effect observed is of the same -nature as in ordinary breathing , the only difference being that , in consequence of the length of the intervals and the absence of expiratory effort , it is much more obvious . The moment after inspiration commences , the mercurial column is jerked up by a succession of forcible contractions of the heart . 5 . Expyeriments showing that in artificial respiration , when the mechanism is reversed , the chemical conditiozns remaining the same , the mechanical efect is correspondingly modifled ; and that if the blood is venous , a chemieal effect is produced by each injection of air into the ltnygs , whickh , although of the same nature , requires a much longer time for its production.-If , in an animal under the influence of woorara , artificial respiration be discontinued until the arterial pressure sinks several inches , and then air is injected , even in small quantity , no immediate effect is observed excepting a momentary increase of arterial pressure coincident in time with the expansion of the lungs ; but after the lapse of six or seven seconds , the heart begins to beat with extreme frequency , rapidly raising the mercurial column until a pressure is attained equal or superior to that originally existing . The length of the time which intervenes between this event and its antecedent is in itself sufficient to show that the relation between the two cannot be mechanical . This is proved by the observation that , if hydrogen be substituted for air in the experiments , no effect is produced . 6 . Experiments showing the relation between the thoracic movements and the arterial pressure after section of the pneumoyastric nerves.-Section of the pneumogastric nerves in the neck , besides its well-known effect in retarding the breathing and accelerating the contractions of the heart , alters the mode of the respiratory movements . The chest is unnaturally dilated even during the pause . Inspiration is performed slowly and with effort , and terminates in a sudden expiratory.collapse . The heart not only contracts more frequently , but more forcibly , the arterial pressure rising several inches of mercury . Under these conditions it is observed ( 1 ) that the arterial pressure tends to increase during the slow inspiration , and to decline during the pause , and ( 2 ) that a more rapid increase of tension occurs simultaneously with expiration . But ( 3 ) no variation is observed of the frequency of the pulsations ; and ( 4 ) all the effects are much less marked than in the normal , animal . These peculiarities are to be attributed to the extreme rapidity of the heart 's action , to the permanent distension of the thoracic veins , and to the violence of the expiratory movements . Theoretical ezposition of the mechanical influence of the respiratory movements on the circulation.-(1 ) It has been demonstrated by Donders that the elastic contents of the chest have at all times a tendency to shrink to a smaller bulk than that of the cavity in which they are contained , so that the viscera within the thorax are constantly distended in a degree which varies according to its ever-varying capacity . As , however , they are not equally elastic , they yield to this distension unequally . When the chest enlarges , the lungs yield most , the veins and heart , in a state of relaxation , next ; the contracting heart and the arteries scarcely expand at all . ( 2 ) If the veins contained air and communicated with the atmosphere , they would fill as rapidly as the lungs ; actually their expansion is much slower . I-ence the first effect of inspiration is to increase the proportion of thoracic space occupied by the lungs , by which they become relatively more distended than the other organs . So soon , however , as the veins and auricles have time to fill , equilibrium is more or less restored . ( 3 ) Hence it follows ( a ) that the dilatation of the chest in inspiration aids the expansion of the heart during diastole and of the thoracic veins ; and ( b ) that these events cannot occur simultaneously with their cause , but must follow at an interval varying according to the condition of the circulation . ( 4 ) Other things being equal , the force and frequency of the contractions of the heart are increased by whatever causes accelerate its diastolic impletion . The more rapidly the cavities fill the shorter must be its period of relaxation , the more vigorous its systole , and consequently the greater the arterial pressure . ( 5 ) The effect of thoracic expansion on the intra-thoracic veins varies both as regards its degree and the time of its occurrence . Both kinds of variation depend on the velocity of the circulation and the pressure existing in the veins outside of the chest . When the systemic veins are distended , the circulation rapid , and the arterial resistance in consequence diminished , the heart almost empties itself at each contraction , and the expansion of the chest fills the thoracic veins and the relaxed heart with great rapidity . In the opposite case , when the systemic veins are comparatively empty , the cavities of the heart fill slowly , and discharge themselves imperfectly on account of the excessive arterial resistance . ( 6 ) Hence the efect of inspiration in facilitating the diastolic impletion of the auricles , and consequently in increasing the frequency and force of the heart 's action , varies directly as the velocity of the circulation , inversely as the arterial pressure . Conclusions.--1 . In natural breathing the influence exercised by the thoracic movements on the heart is entirely mechanical . So long as the respiration is tranquil , variations of air-pressure in the bronchial tubes and vesicles of the lungs do not materially affect the arterial pressure ; but violelt expiratory movements are accompanied by simultaneous increase of vascular tension . 2 . When the respiratory orifices are closed , the variations of bloodpressure in the arteries are synchronical with those of air-pressure in the respiratory cavity , and take place in the same direction . 3 . The increased action of the heart which results from chemical changes produced in the circulating fluid by exposure to air , is of the same nature as the mechanical effect of inspiration , both being indicated by increased arterial tension and acceleration of the pulse . The former may be distinguished from the latter ( a ) by the length of time required for the production of the effect , and ( b ) by its dependence on a previous venous condition of the blood . 4 . Hence the influence of the thoracic movements on those of the heart may be either directly mechanical , as in suffocation , indirectly mechanical , as in ordinary breathing , or chemical .
112658
3701662
Note on Mr. Merrifield's New Method of Calculating the Statical Stability of a Ship
396
397
1,866
15
Proceedings of the Royal Society of London
W. J. Macquorn Rankine
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0088
null
proceedings
1,860
1,850
1,800
2
13
612
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112658
10.1098/rspl.1866.0088
http://www.jstor.org/stable/112658
null
null
Fluid Dynamics
47.526551
Formulae
34.55825
Fluid Dynamics
[ 56.69060516357422, -15.7257080078125 ]
I. " Note on Mr. Merrifield 's New Method of calculating the Statical Stability of a Ship . " By W. J. MACQUORN RANKINE , C.E , LL. D. , F.R.S. Received February 22 , 1867 . On the 24th of January , 1867 , a paper was read to the Royal Society by Mr. C. W. Merrifield , F.R.S. , Principal of the Royal School of Naval Architecture , showing how , by determining the radii of curvature of the locus of the centre of buoyancy or " metacentric involute " of a ship in an upright position and at one given angle of inclination , a formula may be obtained for calculating to a close approximation her moment of stability at any given angle of inclination , on the assumption that the metacentric involute can be sufficiently represented by a conic . It has occurred to me that the latter part of the calculation in Mr. Merrifield 's method might be simplified by assuming for the approximate form of the metacentric involute , not a conic , but the involute of the involute of a circle ; the locus of its centres of curvature , or " metacentric evolute , " being assumed to be the involute of a circle . The involute of the involute of a circle is distinguished by the following property . Let r be the radius of the circle , p , that radius of curvature of the involute of the involute which touches the involute at its cusp , and p another radius of curvature of the same curve making the angle 0 with the radius p0 ; then ro02 P=P+ - ? ... ... . . ( 1 ) Having found , then , the radii of curvature of the metacentric involute in an upright position , and at a given angle of inclination 0 , let po and p , be those radii respectively ; then make 2(p , -p ' , ) 022 This will be the radius of the required circle ; and its positive or negative sign will show whether it is to be laid off downwards or upwards from the metacentre . For any given angle of inclination the radius of curvature of the metacentric involute will be given by equation ( 1 ) , which may also be put in the following form : 02 P Po + ( P1-Po ) 0 ' ... ... . ( 3 ) Let a be the depth of the ship 's centre of gravity below her metacentre , and p the perpendicular let fall from that centre of gravity upon the radius of curvature of the metacentric involute at any given angle of inclination 0 ; then ( == ( --r ) sin 0+r0 ; ... ... . ( 4 ) and the moment of stability is px displacement ... ... ... ( 5 ) It is obvious that the condition of isochronous rolling is that --r =0 ; that is to say , that the centre of the circle which is the evolute of the mnetacentric evolute shall coincide with the ship 's centre of gravity ; a proposition already demonstrated by me in a paper read to the Institution of Naval Architects in 1864 , and published in their Transactions , vol. v. p. 35 . [ Postscript.-Received March 1 , 1867 . ] Since the above was written , I have been informed by Mr. IMerrifield , to whom I had communicated my proposed modification of his method , that it has been tried at the Royal School of Naval Architecture and found to answer well .
112659
3701662
On the Theory of the Maintenance of Electric Currents by Mechanical Work without the use of Permanent Magnets
397
402
1,866
15
Proceedings of the Royal Society of London
J. Clerk Maxwell
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0089
null
proceedings
1,860
1,850
1,800
6
61
2,126
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112659
10.1098/rspl.1866.0089
http://www.jstor.org/stable/112659
null
null
Electricity
66.880149
Fluid Dynamics
18.650147
Electricity
[ 28.67091941833496, -58.227691650390625 ]
II . " On the Theory of the Maintenance of Electric Currents by MechanicalWork without the use of Permanent Magnets . " By J. CLERK MAXWELL , F.R.S. Received February 28 , 1867 . The machines lately brought before the Royal Society by Mr. Siemens and Professor Wheatstone consist essentially of a fixed and a moveable electromagnet , the coils of which are put in connexion by means of a commutator . The electromagnets in the actual machines have cores of soft iron , which greatly increase the magnetic eftects due to the coils ; but , in order to simplify the expression of the theory as much as possible , I shall begin by supposing the coils to have no cores , and , to fix our ideas , we may suppose them in the form of rings , the smaller revolving within the larger on a common diameter . The equations of the currents in two neighbouring circuits are given in my paper " On the Electromagnetic Field " c ' , and are there numbered ( 4 ) and ( 5 ) , d X=R +t ( Lx+My ) , d '-.Sy+ -(Mx + Ny ) , dt where x and y are the currents , t and ? the electromotive forces , and R and S the resistances in the two circuits respectively . L and N are the coefficients of self-induction of the two circuits , that is , their potentials on themselves when the current is unity , and M is their coefficient of mutual induction , which depends on their relative position . In the electromagnetic system of measurement , L , M , and N are of the nature of lines , and R and S are velocities . L may be metaphorically called the " electric inertia " of the first circuit , N that of the second , and L+ 2M+ N that of the combined circuit . Let us first take the case of the two circuits thrown into one , and the two coils relatively at rest , so that M is constant . Then ( R+S)x+ ( L+2M+N)x=0 , ... . . ( 1 ) whence R+S t x=x , e L+2+N ... ... . . ( 2 ) where xo is the initial value of the current . This expression shows that the current , if left to itself in a closed circuit , will gradually decay . If we put L+ 21M+N __ __S , . v. . * Let us next ascertain the effect of a sudden change of position in the secondary coil , which alters the value of M from M1 to M2 in a time t2-t , , during which the current changes from x to 2 . Integrating equation ( 1 ) with respect to t , we get ( R+S ) xdt+ ( L+2M2+N)x2-(L+2M- , +N)x1=O. . ( 5 ) If we suppose the time so short that we may neglect the first term in comparison with the others , we find , as the effect of a suddcen change of position , ( L-+2l +N)-(L+2M , + N ) ... ... ( 6 ) This equation may be interpreted in the language of the dynamical theory , by saying that the electromagnetic momentum of the circuit remains the same after a sudden change of position . To ascertain the effect of the commutator , let us suppose that , at a given instant , currents x and y exist in the two coils , that the two coils are then made into one circuit , and that x ' is the current in the circuit the instant after completion ; then the same equation ( 1 ) gives ( L+2i +N)x ' ( L+M ) +(N +M)y. . ( 7 ) This equation shows that the electromagnetic momentum of the completed circuit is equal to the sum of the electromagnetic momenta of the separate coils just before completion . The commutator may belong to one of four different varieties , according to the order in which the contacts are made and broken . If A , B be the ends of the first coil , and C , D those of the second , and if we enclose in brackets the parts in electric connexion , we may express the four varieties as in the following Table:(1 ) ( 2 ) ( 3 ) ( 4 ) ( AC ) ( BD ) ( AC ) ( BD ) ( AC ) ( BD ) ( AC ) ( BD ) ( ABCD ) ( ABC ) ( D ) ( A ) ( BCD ) ( A ) ( B ) ( C ) ( D ) ( AD ) ( BC ) ( ABCD ) ( ABCD ) ( AD ) ( BC ) ( AD ) ( BC ) ( AD ) ( BC ) In the first kind the circuit of both coils remains uninterrupted ; and when the operation is complete , two equal currents in opposite directions are combined into one . In this case , therefore , y=--r , and ( L 2 ? + N)x'= ( L-N). . ( 8 ) When there are iron cores in the coils , or metallic circuits in which independent currents can be excited , the electrical equations are much more complicated , and contain as many independent variables as there can be independent electromagnetic quantities . I shall therefore , for the sake of preserving simplicity , avoid the consideration of the iron cores , except in so far as they simply increase the values of L , M , and N. I shall also suppose that the secondary coil is at first in a position in which M =0 , and that it turns into a position in which M= -M- , which will increase the current in the ratio of L+ N to L2I + N. The commutator is then reversed . This will diminish the current in a ratio depending on the kind of commutator . The secondary coil is then moved so that iM changes from M to 0 , which will increase the current in the ratio of L+ 2M+ N to L +N . During the whole motion the current has also been decaying at a rate which varies according to the value of L+ 2M + N ; but since M varies from +M to -- , we may , in a rough theory , suppose that in the expression for the decay of the current M= 0 . If the secondary coil makes a semirevolution in time T , then the ratio of the current x , after a semirevolution to the current x0 before the semirevo . lution , will be T jr0 where L+N = + , ... . : ... . . ( 9 ) and r is a ratio depending on the kind of commutator . For the first kind , L-N r= L-2M+N* ** ( 10 ) By increasing the speed , T may be indefinitely diminished , so that the question of the maintenance of the current depends ultimately on whether r is greater or less than unity . When r is greater than 1 or less than 1 , the current may be maintained by giving a sufficient speed to the machine ; it will be always in one direction in the first case , and it will be a reciprocating current in the second . When r lies between +1 and --1 , no current can be maintained . Let there be p windings of wire in the first coil and q windings in the second , then we may write L=pp2 ' , 3=Mmpq , N=q2 ' ... . ( li ) where 1 , mn , n are quantities depending on the shape and relative position of the coils . Since L-2M+ N must always be a positive quantity , being the coefficient of self-induction of the whole circuit , In--2 , and therefore LN-M must be positive . When the commutator is of the first kind , the ratio r is greater than unity , provided pm is greater than qn ; and when pn+ ~ ' = ( L ~~_~. . ++e e* *. . ( 12 ) which is the maximum value of r. When the ratio of p to q lies between that of n to m and that of m to 1 , r lies between +1 and -1 , and the current must decay ; but when pi is less than qm , a reciprocating current may be kept up , and will increase most rapidly when qm V nm and : 3-(1-an ) ... * ... *.(13 ) When the commutator is of the second kind , the first step is to close both circuits , so as to render the currents in them independent . The second circuit is then broken , and the current in it is thus stopped . This produces an effect on the first circuit by induction determined by the equation Lx+My=Lx'+My ' ... ... . ( 14 ) In this case iM=-Mo , y=x , and y'=O , so that ( L-M)x=Lx ' ; ... ... . ( 15 ) where x is the original , and x ' the new value of the current . The next step is to throw the circuits into one , M being now positive . If x " be the current after this operation , ( L+ M)x'=(L+2IM+N)x " ... . . ( 16 ) The whole effect of this commutator is therefore to multiply the current by the ratio L2 _ 1\12 L._M2 L(L+2M+N ) The whole effect of the semirotation is to multiply the current by the ratio L+2M+N L-2M+N ' The total effect of a semirevolution supposed instantaneous is to multiply the current by the ratio L2 M2 L(L2M+N ) ' If p and q be the number of windings in the first and second coils respectively , the ratio r becomes r ( lp2-qr ) which is greater than 1 , provided 21np is greater than ( ln+mm)q . WNhen p l.9t 9\ )+ 1 / +2 3 > Iqe r2\-r 2r l3 -12 we have for the maximum value of r , 2m r=l+ mI In the experiment of Professor Wheatstone , in which the ends of the primary coil were put in permanent connexion by a short wire , the equations are more complicated , as we have three currents instead of two to consider . The equations are a J+d ( Lx+M y)= S+ ( M +Ny ) =Qz + -K , . ( 17 ) d+y4+=0 ... ... ... ... ... ( 18)d +y+xO ... . ( 18 ) where Q , K , and z are the resistance , self-induction , and current in the short wire . The resultant equations are of the second degree ; but as they are only true when the magnetism of the cores is considered rigidly connected with the currents in the coils , an elaborate discussion of them would be out of place in what professes to be only a rough explanation of the theory of the experiments . Such a rough explanation appears to me to be as follows : Without the shunt , the current in the secondary coil is always in rigid connexion with that in the primary coil , except when the commutator is changing . With the shunt , the two currents are in some degree independent ; and the secondary coil , whose electric inertia is small compared with that of the primary , can have its current reversed and varied without being clogged by the sluggish primary coil . On the other hand , the primary coil loses that part of the total current which passes through the shunt ; but we know that an iron core , when highly magnetized , requires a great increase of current to increase its magnetism , whereas its magnetism can be maintained at a considerable value by a current much less powerful . In this way the diminution in resistance and self-induction due to the shunt may more than counterbalance the diminution of strength in the primary magnet . Also , since the self-induction of the shunt is very small , all instantaneous currents will run through it rather than through the electromagnetic coils , and therefore it will receive more of the heating effect of variable currents than a comparison of the resistances alone would lead us to expect .
112660
3701662
On Certain Points in the Theory of the Magneto-Electric Machines of Wilde, Wheatstone, and Siemens
403
404
1,866
15
Proceedings of the Royal Society of London
C. F. Varley
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0090
null
proceedings
1,860
1,850
1,800
2
32
806
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112660
10.1098/rspl.1866.0090
http://www.jstor.org/stable/112660
null
null
Electricity
82.927729
Biography
10.696912
Electricity
[ 28.755258560180664, -58.19089126586914 ]
III . " On certain Points in the Theory of the Magneto-electric Machines of Wilde , Wheatstone , and Siemens . " By C. F.VARLEY , E.sq . In a Letter to Professor STOKES , Sec. R.S. Received February 26 , 1867 . Fleetwood House , Beckenham , S.E. , February 23 , 1867 . MY DEAR SIR , -Professor Wheatstone showed that a shunt put into the circuit of the electromagnet increased the power greatly , but the explanation that it increased the power by equalizing the resistance of the armature and that of the electromagnet is either wholly incorrect , or very nearly so . Yesterday I had an opportunity afforded me by Mr. C. Siemens of experimenting with his machine , in which the electromagnets have each a resistance of about 250 Ohms 500 Ohms , the armature 400 Ohms . On adding a shunt to the electromagnet the flame was greatly increased . The two electromagnets when connected in series had a resistance of about 500 Ohms . I then connected them in a double circuit , the resistance in this case being about 125 Ohms . By this means the same result as regards resistance could be obtained as by a shunt , with the difference that the power expended in the shunt is lost in heat ; while reducing the resistance by the double circuit caused the whole force to be expended on the electromagnet . The results of the experiment were 1st . The shunt invariably increased the power . 2ndly . When the magnets were joined in double circuit the power was greatly reduced . The explanation is to me obvious . In a Ruhmkorff 's coil , where the iron core is divided into fine wire , so that the dying magnetism cannot set up currents in the iron core to prolong its existence , the magnetism is very rapidly lost , and the make-and-break hammer works very rapidly , sometimes as fast as sixty beats per second . If the secondary circuit be closed so that the currents can flow , the makeand-break hammer works very slowly , indeed one or two beats per second ; and in 1856 I published a description of electromagnets whose action was very slow , and which were rendered sluggish by a copper cylinder around them . Wilde 's armature , when revolving , sends intermittent currents around the electromagnet , whose circuit is broken at every half revolution of the armature . Were the magnets composed of fine iron wire , the magnetism would die away rapidly , producing a violent current by its efforts to maintain itself , as in the Ruhmkorff 's coils . ( This current is called by foreigners the extra-current . ) The shunt which Wheatstone inserted carries this current across , and so uaaintains the magnetism of the electromagnets until the armature gives a 403 second impulse . The current in this shunt will be found to travel in alternate directions ; not so that on the electromagnet . When the armature is discharging its current into the electromagnets , the current in the shunt is in the direction it would have if the shunt were in circuit solely with the armature . When the armature is changing poles and is disconnected , the secondary current is in full play , and the current in the shunt is in the direction of the current prolonged in the electromagnet , that is , of the extra current . The force expended in the shunt is wasted in heat ; but a secondary wire on the electromagnet or a copper cylinder would very greatly add to the power by maintaining the magnetism , and not consume uselessly the force now wasted in the shunt . The overlapping of the armature and the solid mass of the electromagnets tends to maintain imperfectly the magnetism during the intervals of no current from the armature ; and but for this the machines , whether they be Wilde 's , Wheatstone 's , or Siemens 's , would none of them work . In 1860 I published a description of two machines I had constructed , and in 1862 , at the Universal Exhibition , I exhibited a machine for adding mechanical force to static electricity without friction . A machine similar in principle , but a little different in construction , has been exhibited recently under the name of HIoltz . One of my machines bears to the other precisely the same relation that Siemens 's or Wheatstone 's does to Wilde 's . If these be of sufficient interest to the Royal Society , I shall be happy to exhibit them . I am , my dear Sir , Very truly yours , C. F. VARLEY .
112661
3701662
On a Magneto-Electric Machine
404
405
1,866
15
Proceedings of the Royal Society of London
William Ladd
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0091
null
proceedings
1,860
1,850
1,800
2
13
405
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112661
10.1098/rspl.1866.0091
http://www.jstor.org/stable/112661
null
null
Electricity
76.456629
Biography
17.071196
Electricity
[ 28.92048454284668, -58.188690185546875 ]
IV . 'On a Magneto-electric Machine . " By WILLIAM LAD , F.R.IM . S. Communicated by Professor STOKES , Sec. R.S. Received March 14,1867 . In June 1864 I received from Mr. Wilde a small magneto-electric machine , consisting of a Siemens 's armature and six magnets . This I endeavoured to improve upon , my object being to get a cheap machine for blasting with Abel 's fusees . This was done by making one of circular magnets , and a Siemens 's armature revolving directly between the poles , the armature forming the circles ; with this I could send a very considerable power into an electro-magnet , &c. It was then suggested to me by my assistant , that if the armature had two wires instead of one , the current from one being sent through a wire surrounding the magnets , their power would be augmented , and a considerable current might be obtained from the other wire available for external work ; or there might be two armatures , one to exalt the power of the magnets , and the other made available for blasting or other purposes . Want of time prevented me carrying this out until now ; but since the interesting papers of C. W. Siemens , F.R.S. , and Professor Wheatstone , F.R.S. , were read last month , I have carried out the idea as follows:-Two bars of soft iron , measuring 712 in . x 22 in . x , in . , are each wound , round the centre portions , with about thirty yards of No. 10 copper wire ; and shoes of soft iron are so attached at each end , that when the bars are placed one above the other there will be a space left between the opposite shoes in which a Siemens 's armature can rotate : on each of the armatures is wound about ten yards of No. 14 copper wire cottoncovered . The current generated in one of the armatures is always in connexion with the electro-magnets ; and the current from the second armature , being perfectly free , can be used for any purpose for which it may be required . The machine is altogether rudely constructed , and is only intended to illustrate the principle ; but with this small machine three inches of platinum wire '01 can be made incandescent .
112662
3701662
Computation of the Lengths of the Waves of Light Corresponding to the Lines in the Dispersion-Spectrum Measured by Kirchhoff. [Abstract]
405
406
1,866
15
Proceedings of the Royal Society of London
George Biddell Airy
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
2
17
491
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112662
null
http://www.jstor.org/stable/112662
null
null
Atomic Physics
37.177453
Astronomy
27.753605
Atomic Physics
[ 18.9923152923584, -47.54957580566406 ]
I. " Computation of the Lengths of the Waves of Light corresponding to the Lines in the Dispersion-Spectrum measured by Kirchhoff . " By GEORGE BIDDELL AIRY , F.R.S. , Astronomer Royal . Received March 2 , 1867 . ( Abstract . ) The author , after adverting to the excellence and importance of the spectral measures made by Professor Kirchhoff , points out that these measures are not available for physical inquiry until we have deduced from them the length of the light-wave corresponding to each line . The author therefore undertook the work of computing the lengths of the light-waves . For this purpose , he referred to Fraunhofer 's direct measures of the lengths of the waves corresponding to certain lines , and , ascertaining the numerical measures in Kirchhoff 's scale corresponding to the same lines , he expressed Fraunhofer 's wave-lengths by an algebraical formula , in which the variable quantity was Kirchhoff 's measure . This formula was applied to each of the lines ( about 1600 in number ) . The wave-lengths were at first obtained in parts of the Paris inch ; but all were ultimately converted into parts of the millimetre . The author then adverts to the suspicion of inaccuracy in some parts of these results , arising from the circumstance that Kirchhoff 's apparatus was not always in precisely the same state of adjustment . After expressing his own a priori belief that the error , if any , must be extremely small , he adverts to the comparison which he was now enabled to make between direct measures of wave-length by Angstr6m and Ditscheiner , and his own computations . Admitting the systematic errors of Fraunhofer which the later philosophers have indicated , and the errors incidental to interpolation and extrapolation , the remaining discrepance is very small . Its progress is so easy that there is no difficulty in interpolating its value for any one line ; and thus , using the computed wave-lengths of this memoir , the wave-length for any line may be found as it would have been measured by 0 Angstrom or Ditscheiner . In the tabular part of the communication , the principal Table contains Kirchhoff 's measures and symybols , extracted from the Berlin Memoirs 1861 and 1862 , with the addition throughout of one column containing the author 's computed wave-lengths expressed in parts of the millimetre . This is followed by a special Table , in the same form , for the lines produced by certain metals not included in the general Table . There is then given a Table of the wave-lengths corresponding to the lines produced by different metals , extracted by the author from the general Table . And finally there are given two Tables containing respectively the comparisons of Angstrom 's and Ditscheiner 's direct measures of wave-lengths with the wave-lengths computed by the author .
112663
3701662
On a Remarkable Alteration of Appearance and Structure of the Human Hair
406
408
1,866
15
Proceedings of the Royal Society of London
Erasmus Wilson
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0093
null
proceedings
1,860
1,850
1,800
3
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http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112663
10.1098/rspl.1866.0093
http://www.jstor.org/stable/112663
null
null
Biology 2
32.180458
Biology 3
30.123243
Biology
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II . " On a remarkable Alteration of Appearance and Structure of the Human Hair . " By ERASMUS WILSON , F.R.S. Received March 12 , 1867 . I have the honour of submitting to the Royal Society a specimen of human hair of very remarkable appearance . Every hair is brown and white in alternate bands , looking as if encircled with rings ; and this change of aspect extends throughout the whole length of the hair , and gives to the general mass a curiously speckled character . The brown segment of the hair , which represents its normal colour , measures about a1 of an inch in length , or something less than a quarter of a line ; the white , or abnormal segment about half that length , namely T1Y of an inch ; and the two together about -1 of an inch , or one-third of a line . The hair was taken from a lad aged seven years and a half , a gentleman 's son ; he is reported as being " an active , healthy boy , quick and intelligent . " He was delicate up to the age of four , having suffered in quick succession the diseases of childhood , a severe attack of croup , and several attacks of convulsions . The change in the appearance of the hair was first noticed when he was between two and three years old , and has 406 AMarch 21 , increased perceptibly during the last two years . There is no similar alteration of structure of the eyebrows and eyelashes . His complexion is dark , while that of a younger brother is fair ; and the latter is free from any alteration of the hair . Examination of the hair with a lens shows that the cylinder of the hair is perfectly uniform , that the white portion is contained within the cuticle and occupies the whole breadth of the cylinder ; whilst it frequently presents a rounded cone at the central extremity , and breaks up into fibres at the opposite or distal end ; and in some instances this fibrous structure is apparent at both ends of the white segment . Moreover , by transmitted light , the white segment is found to be opake , and consequently presents a dark shade , while the intermediate or brown portion has the transparency of normral hair . When the transparency of the hair is increased by immersion in Canada balsam slightly diluted with spirits of turpentine , the white and opake segment is reduced in dimensions , and is rendered more or less transparent by imbibition of the volatile fluid ; moreover it is clearly demonstrated by this process that the opacity of the segment its whiteness when seen by reflected light , and its darkness by transmitted light , are all due to the presence , in the fibrous portion of the hair , of spaces filled with air-globules . The air-spaces are necessarily very numerous and assembled closely together ; while at the ends of the white segment they have more or less of a linear arrangement , and give a fibrous appearance to the opake mass . Moreover the partial transparency of the hair caused by the balsam demonstrates that , besides the air-spaces , large and small , contained in the opake portion , minute air-spaces , sometimes arranged in linear order , and sometimes communicating and forming short irregular canals , are also met with in the transparent part of the hair . And , in addition to the minute air-spaces of the plates of the fibrous portion of the hair , an accumulation of air-globules is also very apparent in the cells of the medulla . It is evident from this examination of the hairs , that they are imperfect in structure and development , and that their imperfection indicates a weak producing organ , and probably a weakly constitution of the individual ; that the cells of which the fibrous portion of the hair is composed , instead of being filled with a horny plasma , are tinged with aqueous fluid , and the desiccation of this fluid leaves behind it vacuities which in the subsequent growth of the shaft become filled with air . The most remarkable phenomenon in connexion with the case , however , is the alternation of imperfect and perfect cells , the period of continuance of the two processes ( supposing them to be equally active in point of time ) being twice as long for the perfect as for the imperfect structure . Since the publication of the observations of Berthold in Miiller 's 'Arcbiv ' for 1850 , it is generally believed that the hair grows faster during the day than during the night ; hence the first suggestion that occurred to me in connexion with the present case , seeing that the white or opake segment . was shorter by one-half than the brown , was that the former represented the slower growth by night , and the latter the quicker growth by day the white and the brown together representing an entire day of twenty-four hours . But other observations by myself have given , as the average growth of the hair of the head in persons who had been shaved , of an inch for the week , and consequently -1 of an inch for the twenty-four hours . Now the length of hair comprehended by the white and the brown in the present case is 1of an inch , and consequently a much more active growth than is normally met with-corresponding , in fact , in a similar ratio , with thirty-seven hours instead of twenty-four . I therefore refrain from speculating upon the cause of alternation of the healthy and morbid structure presented by this case , and restrict myself to the narration of the fact that during a certain space of time , amounting to a day or more , the hair is produced of normal structure , while during another space of time of undetermined extent the hair is produced unhealthily , -that the periods of healthy formation correspond pretty accurately in extent , as do those of unhealthy formation , while the latter , in measurement , are only half as extensive as the former , -moreover , that the differences of the pathological operation are , the production of a horny plasma in the normal process , and of serous and watery cell-contents in the abnormal process . I may further observe that it is by no means improbable that the " dead " and faded hair which is met with after some illnesses and in instances of debilitated health may be due to a similar pathological process , although wanting in the periodicity and alternation which render the present case so remarkable .
112664
3701662
Remarks on the Nature of Electric Energy, and on the Means by Which It Is Transmitted
408
413
1,866
15
Proceedings of the Royal Society of London
Charles Brooke
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0094
null
proceedings
1,860
1,850
1,800
6
50
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http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112664
10.1098/rspl.1866.0094
http://www.jstor.org/stable/112664
null
null
Fluid Dynamics
55.288493
Chemistry 1
14.168424
Fluid Dynamics
[ 29.669160842895508, -56.64564514160156 ]
III . " Remarks on the Nature of Electric Energy , and on the Means by which it is transmitted . " By CHARLES BROOKE , M.A. , F.R.S. , P.M.S. , &c. Received March 19 , 1867 . The writer has clearly shown the interchange of thermic and dynamic energy at the point of junction of the bars of a thermo-electric element of antimony and bismuth* , and he has also pointed outt that the dynamic nature of electric energy is not less clearly irndicated by the long-known fact that an ordinary voltaic current always commences with a rush , as it were , the instant that the circuit is closed . The dynamic cause of this is clearly pointed out by an experiment due to the genius of Prof. Wheatstone . If a tuning-fork , the tail of which is inserted longitudinally into a wooden handle , like a file or chisel , be made to vibrate , and the end of the handle rested obliquely on a table , the resonance of the table will instantly be heard ; but on moving the diapason parallel to itself in any Mr. C. Brooke on the Nature 408 [ March 21 , '* P ? hil . 2Mag . BNov . 1866 . t Ibid. Dec. direction on the table , the resonance ceases , from the perpetual interference of the successive planes of vibration with each other . But now comes the illustration:-On arresting the motion of translation , the resonance immediately recommences , but with a rush or momentary increase of sound : this must unquestionably arise from the resistance offered by the inertia of the molecules of wood to the recommencement of wave-motion ; and the parallel phenomenon in electricity may undoubtedly be similarly accounted for . And the reflex momentary current ( the terminal extra-current of Faraday ) , which is well known to take place at the instant of opening the circuit , is equally susceptible of a dynamic interpretation : it is the analogue of the wave reflected from the fixed end of a stretched cord , after having been imparted by the hand to the free end . The dynamic nature of electric energy is clearly indicated by the dynamo-electric* machine of Holtz , in which dynamic is directly converted into electric energy , and by the cognate machines of Wilde , Wheatstone , Siemens , and Lad , in all of which alike there is an intervening conversion of dynamic into magnetic energy . The enormous amount of currentenergy evolved in Mr. Wilde 's machine when the power of a steam-engine is employed to rotate the armatures may be judged of by the fact that a long piece of platinum wire 0'2 inch in thickness was seen to be disintegrated and partially fused . It is difficult to conceive that in these instances dynamic energy can be converted into magnetic " fluid , " and that again into thermic energy . the conversion of motion into matter , and the subsequent reconversion of matter into motion , are obviously impossible . Some further consideration of the effects of electric energy may serve to indicate the probable nature of the wave-motion . The facts of electric and magnetic polarity imply and necessitate a polarity or directionality il the motion itself , which has no analogue in the waves of sound , light , or heat . This requirement is fully met by the hypothesis of a circular spiral wave , the motion of which is direct or positive if viewed from one end , and retrograde or negative if from the other ; and this suffices to explain the well-known polarity of electric and magnetic induction . Thus far the spiral hypothesis is merely inferential ; but in regard to magnetic wave-motion some strong presumptive evidence may be adduced . It appears from the experiments of Mr. Joule , made more than twenty years ago , that if a suspended mass of copper be , by twisting the suspension , made to rotate between the poles of an unexcited electro-magnet , the rotation of the mass is arrested the instant the magnet is excited ; and furthermore , if the mass be forcibly rotated , heat is developed in it . And it has since been ascertained that if two cylindrical magnets be so placed that their axes lie in the same straight line , their contrary poles being opposed to each other , then , if a cylinder of copper be made to rotate on its own axis , coinciding with the common axis of the magnets , no heat will be evolved by its rotation . Now these phenomena must alike be the necessary consequences of the assumed dynamical theory ; for if the copper molecules be thrown into spiral-wave motion , analogous to that of a pencil of circularly polarized light , then the motion of all the disturbed particles will be one of revolution in planes to which the lines of magnetic force are normals : and the inertia or energy of rotation ( as it has been variously termed ) , the resistance offered by each revolving particle to any change in the direction of its axis of revolution ( as exemplified by the gyroscope ) , will resist the rotation of the mass in any direction perpendicular to that of the axes of molecular revolution , and arrest its motion . And conversely , if the mass be forcibly rotated in the above direction , or in any other direction at right angles to the lines of magnetic force , heat will be freely developed , doubtless by internal friction arising from the perpetual displacement of the planes of molecular revolution . But in the second case , the axis of rotation of the mass coincides in direction with those of the axes of molecular revolution ; hence there is no displacement of the molecular orbits , and consequently no internal friction , and very little if any heat is generated . The rotatory character of the magnetic wave is further confirmed by the known fact that , if a plane-polarized beam pass through a transparent solid in the direction of the lines of force of a powerful electro-magnet , the plane of polarization will be rotated the instant that the magnet is excited . The truth of a theory can be established only by the verification of its necessary consequences ; and it may not be too much to assume that in the present case the evidence already adduced by the writer is , in the entire absence of all contradictory evidence , strongly presumptive of the reality of the hypothesis . It has been authoritatively stated that ordinary electric and magnetic waves cannot both be assumed to be spirals , because each of these forms of energy notoriously evolves the other in a direction perpendicular to its course ; and the question is not without grave dynamical difficulties ; but they may perhaps not be insuperable . It may possibly be that , from some unknown constraining condition or property inherent in magnetic bodies , a spiral wave , on being constrained into a spiral course , may lose its original spirality , and become a secondary spiral , having molecular motion in a direction perpendicular to that of the primary spiral . The relations between electric energy and some of its observed physical results having thus been inferred , the question next arises as to the nature of the media by which the several modes of motion are transmitted . It is unquestionable that sound-waves are transmissible by all kinds of matter ; but can any valid reason be assigned in favour of the still prevalent opinion that other modes of wave-motion are incapable of transmission by ordinary matter ? -this incapacity being implied in the adoption of the self-contradictory hypothesis of an imaginary medium , not cognizable by any known means of perception . It is a remarkable fact that in all the superseded crude notions of physical causation , each phase of physical energy has been presented in the garb either of impalpable , imponderable ( in fact immaterial ) matter itself , or of the vibrations thereof ; and to some of these hypotheses have been successively added some violent supplementary hypothesis , in order adequately to meet the requirements of advancing knowledge . To begin with chemical action:-What are now universally recognized as simple metals were once supposed to consist of some earthy matter ( their oxides ) combined with " Phlogiston , ' the material principle of brilliancy . But , unfortunately for the theory , it was soon found that the metals , on parting with their share of phlogiston ( i.e. becoming oxidated ) , not only did not lose any , but actually acquired weight ; therefore phlogiston was assumed to be not only imponderable , but hyper-imponderablei . e. endowed with the property of absolute levity , or negative weight ! In the next place , the Newtonian theory of light assumed light to consist of molecules ( of course imponderable ) emanating from the source of light , and impinging on the perceptive organs of vision . But this hypothesis would not fit the phenomena of diffraction and interference ; and to suit these physical facts the molecules must either be throvn into periodical " fits " of transmission or reflection , or the ray must be a row of egg-shaped molecules perpetually making isoperiodic somersaults , and plunging into a medium if they come on their heads , or bounding off if they fall against it sideways . Then , again , heat was supposed to consist of material particles emanating from the source of heat ; and as a ball of ice placed in one focus of a concave mirror was found to lower the temperature of a thermometer placed in the conjugate focus , there were assumed to be particles of cold , as well as of heat : it is needless to add how completely the theory of exchanges accounts for these facts . At length these wild speculations were superseded , and light and heat were admitted into the category of wave-motion ; but electricity and magnetism were still supposed to be either single or dual forms of " fluid " matter ; and ( ' Saxa etiam molli dura teruntur aqua " ) these " fluids " are probably still running in the deep channels they have worn in some philosophic minds . But the principle of admitting imponderability into the category of legitimate physical hypotheses had become tacitly accepted ; and the conclusion was at once jumped at by the authors of the undulatory theory that the wave-motions of light and heat take place in an imponderable highly elastic fluid medium , pervading all space , and all matter , denominated " rether : " and this theory , with all its inconsistencies and inconsequences , is still in all probability generally entertained . That some highly elastic and attenuated medium pervades infinite space , as the medium of transmission of the energies of light and heat ( the very main-springs of organic existence ) from the centre of each solar system to its dependent satellites , is a necessary consequence of the undulatory theory : its existence is , in fact , demonstrated by the periodic retardation of Encke 's Comet . But the remainder of the hypothesis , namely that all palpable matter is pervaded by aether for the purpose of transmitting lightand heat-waves , is by no means equally necessary , or even tenable ; for not a shadow of evidence of the inadequacy of all matter to transmit these motions has ever been produced , and in default of such evidence , the contrary hypothesis is at least equally tenable : and moreover the interstitial-tether theory ( in common with all preceding physical theories involving imponderability ) is burdened with grave inconsistencies . In the first place the well-known phenomena of single and double refraction and polarization , whether of light or heat , necessitate the somewhat violent hypothesis that the elasticity of the supposed transmitting medium , rether , is not , as it is in all cognizable fluids , a fixed and certain quality capable of numerical estimation , but an ever-varying quality , depending quantitatively on the elasticity of adjacent matter , and even varying in tzoo or three directions within the same body : it would be not more repugnant to reason to assume that the elasticity of a gas is one thing in a glass bottle and another in one of brass , or that the specific gravity of silver is a function of the moon 's age , or the melting-point of gold dependent on the sun 's zenith-distance . Secondly , the fundamental ideas of inertia , energy , and " work " are inseparably associated with gravitation ; and it seems to imply a contradiction of terms , to impute either inertia or energy ( i. e. the capability of doing work ) to an imponderable particle , which is consequently destitute of attraction for any other particle in the universe . The known enormous velocity ( of probably not less than 250,000 miles in a second ) at which electricity travels through a copper conductor is complete evidence that ordinary matter is capable of transmitting something ( whether matter or motion it signifies nothing for the present argument ) at a considerably greater velocity than the waves of light and heat ; why should not appropriate kinds of matter be assumed capable of transmitting these also ? And if so , the need of the interstitial presence of aether ceases altogether ; and it may with great advantage be excluded from the domains of ponderable palpable matter by the very mild hypothesis that it is not miscible with air , any more than oil , or palpable ether , with water , but that it floats above the boundary surface of our atmosphere . This hypothesis is not repugnant to reason , nor adverse to physical experience . On this supposition it is no longer needed to impute to aether imponderability ; it will then be competent to fulfil its divine mission of transmitting light and heat , without doing any violence to some of the most fundamental notions of dynamics ; and thus imponderability may cease to be reckoned amongst the physical attributes of matter .
112665
3701662
A Comparison between Some of the Simultaneous Records of the Barographs at Oxford and at Kew
413
414
1,866
15
Proceedings of the Royal Society of London
Balfour Stewart
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0095
null
proceedings
1,860
1,850
1,800
2
28
715
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112665
10.1098/rspl.1866.0095
http://www.jstor.org/stable/112665
null
null
Meteorology
59.467068
Biography
21.054631
Meteorology
[ 40.21986770629883, 17.50887107849121 ]
I. " A Comparison between some of the simultaneous Records of the Barographs at Oxford and at Kew . " By BALFOUR STEWART , LL. D. , F.R.S. , Superintendent of the Kew Observatory . Received March 4 , 1867 . Through the kindness of the Rev. Robert Main , director of the Radcliffe Observatory , Oxford , certain marked features of the curves produced by the barographs at Oxford and at Kew were compared together on four separate occasions in the year 1863 . These comparisons are the more interesting that they were all made during squalls or storms ; for on such occasions it is found that the barograph curves exhibiting the height of the barometer from moment to moment present curious characteristic points , without which indeed no such comparisons could be made . The result for these four occasions in 1863 was as follows:aDate G. M. T. w Oxford is before Nature of disturbance . Oxford . Kew . e Oxrord . Kew . Sudden increase of pressure during squall of 30th October 1863 ... ... ... ... 2.30 P.M. 3.9 P.M.§ 39 minutes Sudden increase of pressure ( probably ) . during squall of 21st November 1863 ... ... ... . 4.0 P.M. 4.45 P.M. 45 minutes . Peculiar points in the curves of December 3 , 1863 ( a 2.40 A.M. 3.35 A.M. 55 minutes . stormy day ) ... ... ... ... 6.50 A.M. 7.40 A.M. 50 minutes . Mr. Main has kindly called my attention to a well-marked minimum in the Oxford curve for February 6 , 1867 , which was also a stormy day . This minimum occurred at Oxford at 2.20 A.M. of that day , while at Kew it did not occur until 3.15 A.M. Oxford was thus on this occasion 55 minutes before Kew . The peculiarity of this last occasion is the singular likeness between the two curves . I have not compared together any other features of these curves , nor perhaps could this be done with exactness ; but the general impression is that the changes of pressure at Oxford were followed by similar changes at Kew , only nearly an hour later . It is premature ( until we obtain more information ) to enter into a discussion of the rate of progress of storms ; but we are quite justified in considering the barograph an instrument extremely well adapted to extend our knowledge of atmospheric disturbances . We see that on those very occasions when this knowledge is most interesting the barograph comes forward to our assistance , and presents us with results which could not possibly be obtained otherwise than by a system of continuous registration . It does not , however , follow that , while a continuous record is by far the best , other records are of no value ; for should an observer be placed beside an ordinary barometer during the crisis of a storm , observations made in rapid succession and accurately timed would be of very great assistance . Such an observer would in fact produce approximately a record similar in kind to that of a barograph , although inferior in value . It ought here to be noticed that two stations are not enough to enable us to determine either the direction in which an atmospheric disturbance is propagated or the rate of propagation . It is only on the improbable supposition that all such disturbances travel in a direct line from Oxford to Kew that barographs at these two places might be deemed enough . In order to obtain the greatest amount of information which such instruments are capable of affording , it is evidently necessary to multiply our stations and to distribute them judiciously over the surface of the country . Nor is it desirable to confine ourselves to one meteorological element , but the barograph should be accompanied by a thermograph and a self-registering anemometer . As this is the system about to be pursued by the Board of Trade in their chief meteorological stations in the British Isles , we may reasonably hope that before long we may by this means receive a large accession to our knowledge of the laws which regulate atmospheric disturbances .
112666
3701662
On the Lunar-Diurnal Variation of the Magnetic Declination, with Special Regard to the Moon's Declination. [Abstract]
414
416
1,866
15
Proceedings of the Royal Society of London
G. Neumayer
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
3
32
1,048
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112666
null
http://www.jstor.org/stable/112666
null
108,979
Meteorology
57.471598
Tables
17.570103
Meteorology
[ 48.3223991394043, 5.957624435424805 ]
II . " On the Lunar-diurnal Variation of the Magnetic Declination , with special regard to the Moon 's Declination . " By G. NEvMAYER . Communicated by the President . Received March 11 , 1867 . ( Abstract . ) The hourly records of the magnetic declination systematically kept at the Flagstaff Observatory at AIelbourne , Victoria , during the period from the 1st of May 1858 to the 28th of February 1863 , have been discussed by the author , with a view to determine the lunar-diurnal variation to which that magnetic element is subject . The results arrived at in the course of this discussion elicit , he believes , facts hitherto unnoticed , to which it seems desirable that the attention of scientific men should be directed . The process employed in reducing the observations was identical with that generally adopted in such cases . The disturbed observations were first eliminated , by rejecting all that differed from the final normal belonging to the same solar hour by more than a certain separating value , which was taken at 3'61 minutes of arc . The elimination of the larger disturbances having been thus effected , from every remaining reading ( R ) of the magnet 's direction the final normal ( N ) belonging to that solar hour was subtracted , so that the residue R--N is devoid of the influence of the solardiurnal variation . This residue is positive when the north end of the needle is to the east of its mean position , and negative in the contrary case . The number of observations at command amounted to 38,194 , of which 4178 single observations were excluded from the discussion as being beyond the assumed limit used for separating the greater magnetic disturbances , leaving 34,016 available for the purpose of determining the lunar-diurnal variation . The treatment of the residues with a view to classification according to lunar hours presented no particular novelty . It may be mentioned , however , that before entering on any general discussion , every month 's result was calculated separately . The values for the various months were afterwards arranged , irrespectively of the year , in two groups , viz. Sun South ( October to March ) and Sun North ( April to September ) . Thus the mean lunar-diurnal variation was obtained separately for each half of the year , as well as for the whole year . On examining the results , irregularities in the lunar-diurnal variation presented themselves which seemed to show that that variation depended in some degree on the moon 's position with reference to the equator , on the circumstance whether her declination were north or south . Accordingly the whole series of observations were rearranged in groups , " Declination of the Moon South " and " Declination of the Moon North , " so as to cause her declination to be divided between the hours of the day , all those days being rejected on which the moon was close to the equator . The 118 groups of lunar-diurnal variation thus formed were subsequently classified according to whether the sun 's declination was south or north . A Table was thus formed giving for each lunar hour the lunar-diurnal variation of the magnetic declination separately under each of nine conditions formed by combining each of the three conditions , Sun South and North , Sun South , Sun North , with each of the three Moon South and North , Moon South , Moon North . The results given numerically in the Table were also laid down graphically in curves . A glance at the curves shows that the lunar-diurnal variation must be regarded as being influenced by both the sun and the moon ; for it is seen that in case the declinations of the two bodies are of the same name , the curves show greater regularity than in the contrary case . The question whether during the winter season any lunar-diurnal variation can be traced at all can , the author conceives , no longer be entertained if we pay due attention to the facts which may be gleaned from the Table . Indeed it is afterwards shown , in discussing the individual years of observation , that in some cases the lunar-diurnal variation manifests itself in a very striking manner during the winter months . On examining the results of the inquiry for the several years of observation , obvious differences are recognized on comparison . This was especially remarkable as regards the year 1861 , which was the more striking as the year 1860 did not exhibit any such extraordinary deviations from the mean values . At first some error was suspected in the deduction of the results ; but a perfectly independent and fresh discussion gave results agreeing in the main points with those previously arrived at . In the course of the year 1861 the instruments previously in use were replaced by fresh ones obtained from Munich , which came into use for regular registration at the beginning of June . Though every care was taken to ensure uniformity of registration , it was deemed satisfactory to repeat the discussion , including that part only of 1861 in which the old instruments were employed ; and accordingly the lunar-diurnal variation was discussed , with special regard to the moon 's declination , for the year May 1860 to April 1861 , and likewise for the year May 1858 to April 1859 ; but it was still found that towards the latter part of the former period the anomalies above pointed out made themselves clearly felt . The results for the years 1860 and 1861 were given numerically in a special Table , and delineated in curves . In conclusion , the author expressed a hope that the few facts he had brought forward might operate as an inducement to those who are engaged in similar pursuits , to enter upon such a laborious task as that of classifying magnetic observations for the purpose of examining into the law and nature of the lunar-diurnal variation , according to the moon 's position north or south of the equator .
112667
3701662
Researches on Gun-Cotton.--Second Memoir. On the Stability of Gun-Cotton. [Abstract]
417
420
1,866
15
Proceedings of the Royal Society of London
F. A. Abel
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
4
49
1,974
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112667
null
http://www.jstor.org/stable/112667
null
null
Chemistry 1
33.370473
Chemistry 2
24.622043
Chemistry
[ -24.192028045654297, -35.20555114746094 ]
1 . " Researches on Gun-cotton.-Second Memoir . On the Stability of Gun-cotton . " By F. A. ABEL , F.R.S. , V.P.C.S. Received March 9 , 1867 . ( Abstract . ) The results of the many observations which had been instituted prior to 1860 upon the behaviour of gun-cotton when exposed to diffused or strong daylight , or to heat , although they agree generally with those of the most recent investigations on the subject , as far as relates to the nature of the products obtained at different stages of its decomposition , cannot be regarded as having a direct bearing upon the question of the stability of gun-cotton produced by strictly pursuing the system of manufacture prescribed by von Lenk , inasmuch as it has been shown that the products formerly experimented upon by different chemists varied very considerably in composition . The investigations recently published by Pelouze and Maury* , into the composition of gun-cotton , and the influence exerted by light and heat upon its stability , are described as having been conducted with gun-cotton prepared according to von Lenk 's system . The general conclusion arrived at by those chemists with reference to the latter branch of the subject was to the effect that the material is susceptible of spontaneous decomposition , under conditions which may possibly be fulfilled in its storage and application to technical and warlike purposes ; and the inference is drawn , partly from the results of earlier investigators , and partly from the exceptional behaviour of one or two specimens , that gun-cotton is liable to explode spontaneously at very low temperatures when stored in considerable quantities . It has been shown , in the memoir on the Manufacture and Composition of Gun-cotton , published last yeart , that modifications in the processes of conversion and purification , which appear at first sight of very trifling nature , exert most important influences upon the composition and purity of the product . Gun-cotton of quite exceptional character has been discovered , in several instances , among samples received from Hirtenberg and among the first supplies obtained from Stowmarket ; other exceptional products have also been produced by purposely modifying , in several ways , the system of manufacture as pursued at Waltham Abbey . The very considerable difference exhibited between some of these and the ordinary products in their behaviour under equal conditions of exposure to heat and light , affords good grounds for the belief that the attainment of certain exceptional results , upon which the conclusions of Pelouze and Maury 's report condemnatory of gun-cotton , have been principally founded , are to be ascribed to such variations in the nature of the material operated upon . Very numerous and extensive experiments and observations have been carried on during the last four years at Woolwich , both with small and large quantities of gun-cotton , for the purpose of completely investigating the conditions by which the stability of this substance , when under the influence of light and heat , may be modified , and with the view of ascertaining whether results recently arrived at in France apply to gun-cotton as manufactured in this country . The principal points which have been established by the results arrived at in these investigations may be summed up as follows:1 . Gun-cotton produced from properly purified cotton , according to the directions given by von Lenk , may be exposed to diffused daylight , either in the open air or in closed vessels , for very long periods without undergoing any change . The preservation of the material for 3years under those conditions has been perfect . 2 . Long-continued exposure of the substance in a condition of ordinary dryness to strong daylight and sunlight produces a very gradual change in gun-cotton of the description defined above ; and therefore the statements which have been published regarding the very rapid decomposition of gun-cotton when exposed to the sunlight do not apply to the nearly pure trinitrocellulose obtained by strictly following the system of manufacture now adopted . 3 . If gun-cotton in closed vessels is left for protracted periods exposed to strong daylight or sunlight in a damp or moist condition , it is affected to a somewhat greater extent ; but even under these circumstances the change produced in the gun-cotton by several months ' exposure is of a very trifling nature . 4 . Gun-cotton which is exposed to sunlight until a faint acid reaction has become developed , and is then immediately afterwards packed into.boxes which are tightly closed , does not undergo any change during subsequent storage for long periods . ( The present experience on this head extends )ver 3years . ) 5 . Gun-cotton prepared and purified according to the prescribed system , and stored in the ordinary dry condition , does not furnish any indication of alteration , beyond the development , shortly after it is first packed , of a slight peculiar odour and the power of gradually imparting to litmus , when packed with it , a pinkish tinge . 6 . The influence exercised upon the stability of gun-cotton of average quality , as obtained by strict adherence to von Lenk 's system of manufacture , by prolonged exposure to temperatures considerably exceeding those which are experienced in tropical climates is very trifling in comparison with the results recently published by Continental experimenters relating to the effects of heat upon gun-cotton ; and it may be so perfectly counteracted by very simple means which in no way interfere with the essential qualities of the material , that the storage and transport of gun-cotton presents no greater danger , and is , uuder some circumstances , attended with much less risk of accident than is the case with gunpowder . 7 . Perfectly pure gun-cotton , or trinitrocellulose , resists to a remarkable extent the destructive effects of prolonged exposure to temperatures even approaching 100 ? C. ; and the lower nitroproducts of cellulose ( soluble gun-cotton ) are at any rate not more prone to alteration when pure . The incomplete conversion of cotton into the most explosive products does , therefore , not of necessity result in the production of a less perfectly perfectly permanent compound than that obtained by the most perfect action of the acid mixture . 8 . But all ordinary products of manufacture contain small proportions of organic ( nitrogenized ) impurities of comparatively unstable properties , which have been formed by the action of nitric acid upon foreign matters retained by the cotton fibre , and which are not completely separated by the ordinary , or even a more searching process of purification . It is the presence of this class of impurity in gun-cotton which first gives rise to the development of free acid when the substance is exposed to the action of heat ; and it is the acid thus generated which eventually exerts a destructive action upon the cellulose-products , and thus establishes decomposition which heat materially accelerates . If this small quantity of acid developed from the impurity in question be neutralized as it becomes nascent , no injurious action upon the gun-cotton results , and a great promoting cause of the decomposition of gun-cotton by heat is removed . This result is readily obtained by uniformly distributing through gun-cotton a small proportion of a carbonate , the sodic carbonate , applied in the form of solution , being best adapted to this purpose* . 9 . The introduction into the finished gun-cotton of 1 per cent. of sodic carbonate affords to the material the power of resisting any serious change , even when exposed to such elevated temperatures as would induce some decomposition in the perfectly pure cellulose-products . That proportion affords , therefore , security to gun-cotton against any destructive effects of the highest temperatures to which it is likely to be exposed even under very exceptional climatic conditions . The only influences which the addition of that amount of carbonate to gun-cotton might exert upon its properties as an explosive would consist in a trifling addition to the small amount of smoke attending its combustion , and in a slight retardation of its explosion , neither of which could be regarded as results detrimental to the probable value of the material . 10 . Water acts as a most perfect protection to gun-cotton ( except when it is exposed for long periods to sunlight ) , even under extremely severe conditions of exposure to heat . An atmosphere saturated with aqueous vapour suffices to protect it from change at elevated temperatures ; and wet or damp gun-cotton may be exposed for long periods in confined spaces to 1000 C. without sustaining any change . Actual immersion in water is not necessary for the most perfect preservation of gun-cotton ; the material , if only damp to the touch , sustains not the smallest change , even if closely packed in large quantities . The organic impurities which doubtless give rise to the very slight development of acid observed when gun-cotton is closely packed in the dry condition , appear to be equally protected by the water ; for damp or wet gun-cotton , which has been preserved for three years , has not exhibited the faintest acidity . If as much water as possible be expelled from wet gun-cotton by the centrifugal extractor , it is obtained in a condition in which , though only damp to the touch , it is perfectly non-explosive ; the water thus left in the material is sufficient to act as a perfect protection , and consequently also to guard against all risk of accident . It is therefore in this condition that all reserved stores of the substance should be preserved , or that it should be transported in large quantities to very distant places . If the proper proportion of sodic carbonate be dissolved in the water with which the gun-cotton is originally saturated for the purpose of obtaining it in this non-explosive form , the material , whenever it is dried for conversion into cartridges , or employment in other ways , will contain the alkaline matter required for its safe storage and use in the dry condition in all climates . Although some experiments , bearing upon the different branches of inquiry included in this memoir , are still in progress with a view to the attainment of additional knowledge of the conditions which regulate the stability of gun-cotton , it is confidently believed that the results arrived at amply demonstrate that the objections which have been of late revived , especially in France , against the employment of gun-cotton , on the ground of its instability , apply , only in a comparatively slight degree to the material produced by strictly pursuing the system of manufacture perfected by von Lenk-that , as far as they do exist , they have been definitely traced to certain difficulties in the manufacture of pure gun-cotton which further experimental research may , and most probably will , overcome-but that , in the meantime , these objections are entirely set aside by the adoption of two very simple measures , against the employment of which no practical difficulties can be raised , and which there is every reason to believe must secure for this material the perfect confidence of those who desire to avail themselves of the special advantages which it presents as an explosive agent . The nature of the decomposition of gun-cotton when exploded under different conditions is now under investigation by me ; and the results arrived at will , I trust , be communicated before long to the Royal Society .
112668
3701662
Observations of Temperature during Two Eclipses of the Sun (in 1858 and 1867)
421
423
1,866
15
Proceedings of the Royal Society of London
John Phillips
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0098
null
proceedings
1,860
1,850
1,800
4
80
1,613
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112668
10.1098/rspl.1866.0098
http://www.jstor.org/stable/112668
null
null
Astronomy
40.639703
Meteorology
21.556065
Astronomy
[ 78.975341796875, 30.551685333251953 ]
II . " Observations of Temperature during two Eclipses of the Sun ( in 1858 and 1867 ) . " By JOHN PHILLIPS , M.A. , LL. D. , D.C.L. , F.R.S. , Professor of Geology in the University of Oxford . Received April 3 , 1867 . On the 15th of March 1858 , occurred an annular eclipse of the sun , whose central line of shadow passed near the village of Steeple Aston , a few miles north of Oxford . Ample preparations were made for observing it by residents in Oxford , and they were met on the ground by many persons from a distance ; Mr. Lassell being one of the party , there was no lack of telescopic power . The day was unfavourable-cold and cloudy , with some occasional feeble and delusive gleams , scarcely permitting a sight of the progress of the eclipse , which , however , was obvious enough by the growing and diminishing darkness . Under these circumstances I devoted my principal attention to three thermometers , carefully selected and compared beforehand-one mercurial with blackened bulb , another mercurial with clear bulb ( these were placed in an open space exposed to the sun ) ; the third , a minimumspirit thermometer , tint red , was placed in a shaded situation . The observations began at 11h 30m and lasted till 2h 30m , thus including the whole period of the eclipse , which began at 1 1h 35 ' , reached the maximum of obscuration at Oh 54m , and ended at 2h 1 Im. The apparent semidiameters of the sun and moon were so nearly equal that the eclipse was almost total ( 0 The observations were recorded as follows : ThermoClear Dark Hour . meter in thermothermoRemarks . shade . meter in meter in sun . sun . hm 11 30 49-0 51'6 58-0 Gleams . 35 Beginning of eclipse . 45 49'0 50'0 55'0 Gleams . 12 0 48-5 49-5 54-5 15 48-5 49-0 52-0 30 48-1 48-5 50'0 45 48-1 48-5 49 2 54 This was the moment of greatest obscuration . 10 47'5 47'5 47'5 Lowest temperature . 15 47-5 47-5 48-0 30 47-6 48 0 48-8 45 48-0 49-4 51-0 20 48-3 49-8 51-7 11 End of eclipse . 15 490 50-5 53-1 Rain began . 30 48-0 49-5 51-2 Rain continued . Mean ... 48-3 49-6 51-5 Max ... . 490 51 6 58'0 Min ... 47-5 47-5 47-6 Range ... 15 4-1 10-4 421 During the late partial eclipse of the sun on the 6th of March 1867 , observations of the ingress of the moon were favoured at Oxford by brilliant weather ; within five minutes after the moment of maximum obscuration ( 17--0 ) clouds appeared ; and from h tme ll n this time till the end of the eclipse they never wholly disappeared , but did not prevent the progress of the moon and the degrees of obscuration from being correctly marked . At the very end it was only just possible to observe the egress by a momentary attenuation of the clouds ; the remainder of the day was cold , cloudy , and finally snowy . The observations began at 8h and ended at 10h 50 " , thus including the whole period of the eclipse , which began at 8h 12m 15 , reached the greatest obscuration at 9h 26m , and ceased at 10 " 45m 8s . At the moment of greatest obscuration the light-giving area was reduced to one-third of the solar disk . The observations comprised(1 ) Temperature in the shade , by the mean of one mercurial and one spirit thermometer very nearly agreeing throughout . ( 2 ) Temperature in the sunlight , by a clear mercurial bulb . ( 3 ) Temperature in the sunlight , by a dark mercurial bulb . ( 4 ) Temperature in the sunlight , by a dark mercurial bulb enclosed in a glass tube exhausted of air . The observations were recorded at intervals according to convenience ( 3m to 20m ) , the shorter intervals being purposely chosen about the time of maximum obscuration . The results are in the following Table : Thermometer in shade . 35.5 Beginnir 36-2 36-7 36-7 36-7 36-7 This was 36-7 36-7 ... ... 37.7 End of e 38-8 37-2 38-8 35-5 3-3 Clear Dark bulb in bulb in sun . sun . 39*5 410 ig of eclipse . 44-0 48-0 44-0 46-5 43-6 46-5 41-5 43-0 40-5 43-0 the moment of gre , 41-5 43-2 38'0 38-0 40-0 40-5 40-0 41-0 42-5 44-5 42-7 44-0 3clipse . 42-0 43-0 41'5 44-0 38'0 60 43-2 48-0 38-0 10-0 Dark bulb in Rm glassemarks . tube . 54'0 Sky always clear till the middle of the eclipse . 58-8 57-8 52-0 46-5 43.5 atest obscuration . 42-9 'Clouds gathered at 91 41-0 30"m and continued 42-0 to the end of the 43'3 eclipse . 46-8 49-9 50'0 48-4 58 8 41-0 17-8 IHour . h in 80 12 25 45 90 18 25 26 32 35 50 10 0 15 35 45 50 Mean ... Max ... . Min ... . Range. . 422 iII [ April 4 , tS I/ / . . / ! a-st ____ __ i ... ._ ... .._ ... . _ ... . . _/ II / ii " _./ 2 1 _i / /i < --.------.--.-..-.-.-4---- ... ... . if i 11 i i.-- ... ... ... ... . -- ... ... . , ... j -_ --_ _ . _ , _ __ . __ _ < ___ ___ . _ ca '1 1i / II '-1 ''--lJ / - , -I/ . . _/ / _I_ " H / , '/ / /I/ / , . : / __ ------------_-____ _ " i. > $C B > okr Ii I : f On considering the columns of figures with attention , it will be perceived that on each occasion all the thermometers in the sunshine sank as the eclipse advanced , so as to reach the greatest depression not at , but after the epoch of greatest obscuration , and from this point rose again as the obscuration diminished , but in neither case arrived at the same elevation as in the beginning of the eclipse . In each case the eclipse began with fair prospects , but was followed by rain or snow . In the annular ( almost total ) eclipse three thermometers , two in the sunshine and one in the shade , reached the very same point ( 47 ? '5 ) , that being the lowest observed ; in the partial eclipse , three thermometers corresponding to the above reached nearly the same point ( 36 ? " 7 , 38 ? , 38 ? ) , the lowest observed . The lowest point was not reached on either occasion by these instruments till some minutes after the moment of greatest obscuration ( 6 minutes in the annular and 9 minutes in the partial eclipse ) ; while the thermometer enclosed in a tube did not sink below 41 ? at the same time . The later occurrence of the extreme depression in the partial eclipse was occasioned by the additional cooling influence of the clouds which gathered five minutes after the epoch of greatest obscuration . By representing the observations in curves with ordinates proportioned to the depressions at the successive epochs , the circumstances which have been referred to are clearly seen , the convergence of all the lines beyond the time-point of greatest obscuration the exactitude of this convergence in the uniformly clouded sky of 1858 , and the comparative confusion of the lines in the suddenly altered sky of 1867 , where the effect of the access of cloud is 1 ? '9 on the enclosed thermometer , 3 ? '5 on the clear exposed bulb , and 5 ? '2 on the black exposed bulb ( see Plate IX . ) . The effect of the cloud on the instruments employed in the latter half of the eclipse is to reduce the temperatures at the end of the eclipse , as compared with the beginning , more than 8 ? in the enclosed thermometer , 5 ? in the dark-bulb exposed , and 2 ? in the clear-bulb ; but in the shaded instruments the effect is contrary , for they gained 2 ? '6 between beginning and end . Finally , if the areas of obscuration be calculated for the several epochs of observation ( in 1867 ) , and the proportions be represented by a curve adapted to the scale used for temperature , the fact of the postponement of the radiation-effect will appear , as well as the conformity with which the temperatures follow the curve , in the bright half of the eclipse , and fall away from it , but still proportionately , in the clouded half , REFERENCE TO PLATE IX . In the diagram for 1858 , the temperatures observed at the several epochs are marked by the crossing of the lines SS for shade , WW for clear bulb , and BB for black bulb , The central time of the eclipse is marked C C. In that for 1867 , similar letters mark similar observations ; and , in addition , W shows the temperatures of the black bulb in vacuo , and OQ the curve of relative obsc-u ration at the several epochs of observed temperature . 423
112669
3701662
A New Fact Relating to Binocular Vision
424
429
1,866
15
Proceedings of the Royal Society of London
A. Claudet
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0099
null
proceedings
1,860
1,850
1,800
6
60
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http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112669
10.1098/rspl.1866.0099
http://www.jstor.org/stable/112669
null
null
Optics
67.086904
Fluid Dynamics
16.15123
Optics
[ 14.458131790161133, -12.336325645446777 ]
I. " A new fact relating to Binocular Vision . " By A. CLAUDET , F.R.S. Received March 20 , 1867 . The persistence of the impression made by light on the retina is demonstrated by many experiments ; but one of the most convincing , which is also very easy to try , is that which is known under the name of the thaumatrope . , Let us write the letters composing a word of eight letters , say " Victoria , " on the two sides of a small card , in such a manner that one surface shall contain the 1st , 3rd , 5th , and 7th letters , and the other surface the 2nd , 4th , 6th , and 8th , with a space between them sufficient to complete the word on each surface , which blank spaces are in fact to appear filled up during the experiment by an artificial means to be explained . Fig. 1 shows the arrangement on the two sides of the card ( section view ) . Fig. 1 . __~~~~~~ Fig. 2 shows the plan of the card . The white letters are those written on one surface , and the dotted lines those written on the other . Fig. 2 . Now by means of two strings fixed on the two sides A , B the card may be made to revolve on its axis by turning the string between the thumb and finger of each hand . By this means a very rapid motion may be communicated to the card , and while it is revolving both surfaces are alternately seen in quick succession , and the perception of the two is so simultaneous that the two sets of letters appear as one , and the whole word is read as distinctly as if it were written on one surface only . This is easily explained . It is known that the persisting action of light on the retina has a duration of about one-eighth of a second ; so that if the card makes at least eight revolutions in a second ( it may make considerably more ) , before one impression has vanished another produces its effect on the next part of the retina , in such a way that they are intermixed and simultaneously visible , producing an uninterrupted sensation . The means by which this illusion is produced has been called the " thaumatrope , " from two Greek words meaning " wonder " and " turn . " It is difficult to trace the history of this discovery ; but it is certain that it lias been the result of a very old , simple , and well-known experiment . From time immemorial schoolboys have amused themselves by holding a coin between two pins and making it revolve rapidly by blowing upon it , when to their surprise the coin showed the head mixed with the device on the other side . I have been told that as Sir John Herschel was one day making this experiment to amuse his children , in the presence of the late Dr. Paris , this gentleman was struck with the idea that if , instead of a coin , a white card was employed on each side of which one part of a design was properly arranged , the two might complete the subject during the revolution . Accordingly he made the experiment , which succeeded perfectly well . If the story is true , certainly Dr. Paris may be regarded as the inventor of the thaumatrope , which he has so well and so fully elucidated in his very interesting and instructive work entitled ' Philosophy in Sport made Science in earnest . ' This philosophical toy may be employed to show another effect of the persistence of the retinal image . If complementary colours are fixed on the two opposite sides of the card , they will become superposed during the revolution , and white light will be the result . By the same means , other curious effects of the mixture of various colours might be tried . All these experiments present no difference , whether they are made looking with the two eyes or only with a single eye : the effect is the same in both cases . Therefore the illusion is equally monocular and binocular . But I was not a little surprised to find that the thaumatrope is capable of producing another phenomenon , elucidating very forcibly the principles by which binocular vision is the only real and effective means of showing the distances of objects , which are determined by the degree of the angle of convergence of the optic axes and by one of its corollaries , the sensation of double images for all the points which are not exactly on the plane of vision . The thaumatrope is capable of showing that binocular vision can detect to a degree hardly conceivable the most minute difference in the distances of objects , such as the distance between the planes of the two surfaces of a card , which distance is nothing more than the thickness of the card . Therefore , supposing that the thickness of the card is -y of an inch and the distance from the eyes 15 in , there is not a difference greater than the 2part of the whole distance from the eyes to the two planes of the card ; and still the difference of the degree of convergence for two planes so near each other is sufficient to excite the action of binocular vision , and by it to enable us to detect that infinitesimal difference in their distances . But that such an effect of binocular vision could possibly be displayed while looking at two planes so nearly intermixed as the surfaces of a card revolving upon its axis with such a wonderful velocity is the very extraordinary pheno menon I have discovered , and which I am about to describe and endeavour to explain . If the thickness of the card is A B , fig. 3 , and if the two ends of each Fig. 3 . string , passing through the holes C and D in the card , are brought together and turned between the thumb and finger , the card will whirl exactly on its axis , and during the revolution the two surfaces A and B will be at the same distance from the eyes . But if the two strings are drawn so that one of their knots is as in fig. 4 , Fig. 4 . the surface B will revolve round the plane of the surface A corresponding with the axis of the string , and , during the revolution , every time that it is made visible to the eyes it will appear as if it were nearer than the surface A. By reversing the position of the knots , as in fig. 5 , instead of the surface Fig. 5 . B revolving round the plane of A , it will be A that will revolve round the plane of B. These three different positions of the strings will produce three different effects . In the position of fig. 3 the effect will be normal ; that is to say , the two surfaces coming alternately at the same distance , we shall see the whole word as if the letters were on the same surface . In the position of figs. 4 and 5 we have a very strange illusion . One half of the letters composing the word will appear before or behind the other half , according to the surface upon which they are written and the position of the knots upon that or the other surface . In fig. 4 the letters written on the surface B will appear before the letters on the surface A ; and in fig. 5 the letters on the surface A will appear before the letters on the surface B. The cause of the anomaly resulting from the two different experiments is entirely and positively due to a sensation of binocular vision ; and we may easily satisfy ourselves that it is so ; for , looking with a single eye in both cases , all the letters appear on the same plane , notwithstanding the different distances of the two surfaces given by the position of the knots : and we may add another convincing proof , which is that the pseudoscope inverts the distances of the surfaces . At first it is rather difficult to understand how the phenomenon can take place ; for as the perception of the two surfaces is simultaneous , how is it possible that during such a rapid revolution the optic axes can be made to converge alternately on each surface while it is passing so quickly , and that they should be made suddenly to converge on the other in its turn ? However , there cannot be any question that in reality the phenomenon takes place , and that it is decidedly an effect of binocular vision ; therefore it only remains to be explained how it can be produced . In endeavouring to arrive at the true cause of the phenomenon , we shall have to bring to mind various physiological sensations which concur in producing the effect . One is the effort we make to obtain distinct vision , and the other the effort we make to obtain single vision . These two efforts act in unison ; for it is impossible not to admit that the two muscular processes by which both the angle of convergence is directed to the object and the focus of the eyes is adapted to its distance , for the double purpose of having at once single and distinct vision of every object , are two actions necessarily simultaneous and inseparably connected . They are therefore both , each in its way , criteria of the distances of objects ; but they give rise to certain indirect and additional criteria for other distances , in two ways : one , the most important , is the double images of the objects situated before and behind the point of convergence ; and the other , but only in a subsidiary way , the degree of confusion of the objects situated before and behind the point of convergence and which are not in focus . The comparison of two points , one of which is in focus and well defined , and the other out of focus and confused , helps considerably in forming ajudgment that they are on different planes . But in a question of binocular vision , perhaps we ought not strictly to take into account this last criterion , which belongs equally to monocular and binocular vision ; and if we allude to it , it is only because , although it does not produce the real stereoscopic effect , still it contributes to give that sort of illusion of relief which by various means may be evinced by monocular vision . Therefore it is particularly the sensation of double images , the degree of their separation , and their respective positions either outside or inside from the centres of the two retinae , which indicate more powerfully the exact distance of the object from the point of single vision either before or behind . When we look fixedly on a point of one surface of the revolving card , that point appears single , and we see at the same time another point on the other surface which appears double , although we hardly feel that we notice its doubleness ; and from the position or distribution of the double images , either on the right or on the left of the central point , we have at the same glance the perception of the respective distances . Therefore , to judge of the distances of certain objects in the direction of the line of vision , we are not absolutely obliged to alter constantly the angle of convergence . This is proved by our perception of the two distances of the surfaces of the card while it is revolving ; for it would be impossible that we should alter the angle of convergence to adapt it alternately to the two surfaces while they are turning so rapidly . The same angle of convergence kept on one or the other surface is no impediment to our seeing both in a sufficiently distinct manner . The whole phenomenon may be better understood by the illustration given in fig. 6 . Fig. 6 . When we converge the optic axes on B , this point , being represented on the centre of both retine at B ' Bt , is single , but A being nearer is represented on the left of the centre of the left retina at A ' , and on the right of the centre of the right retina at A " ; therefore it appears double . For the same reason , converging on A , this point is single , but B is double , with this difference-that one image is on the right of the left retina , and the other on the left of the right retina ; so that the double images of nearer objects situated at A are represented outside the centres of the two retine , and those of further objects situated at B are represented inside the centres of the retinae , and each of these two different sensations brings to our mind the perception of the distance which has produced it . During the revolution of the card we may adapt the convergence either to one or to the other slrface and keep it so ; but in every case the letters on that surface will appear single and a little better defined ; and this , with the sensation of double images of the letters on the other surface , will be an indication of their respective distances . As I am not aware that the illusion I have described in this paper has ever been noticed before , it has appeared to me that its publication would excite the interest of all those who look for any new fact capable of illustrating the principles of binocular vision , and showing the wonderful pro perty of the angle of convergence , by which the most minute differences in the distances of objects and the slightest relief on their surfaces can be detected , and by which also in the abnormal conversion introduced in its action by the pseudo ? cope all our sensations are reversed . Therefore the pseudoscope is the great test of the phenomena of binocular vision ; for by reversing certain sensations which by constant habit we may hardly notice , it renders them more conspicuous by the comparison of the abnormal state brought out by its action , and proves the theory of binocular vision in the most effective manner . A truth is never better established than when it can be shown that the same principles are capable of producing contrary effects when they are applied in a contrary way . Professor Wheatstone , by adding the pseudoscope to the stereoscope , has thus in the most scientific and ingenious manner completed his splendid discovery , and left very little ( we might almost venture to say that he has left nothing ) for further investigations in the physiology of binocular vision .
112670
3701662
On the Calculation of the Numerical Value of Euler's Constant, Which Professor Price, of Oxford, Calls E
429
432
1,866
15
Proceedings of the Royal Society of London
William Shanks
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0100
null
proceedings
1,860
1,850
1,800
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http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112670
10.1098/rspl.1866.0100
http://www.jstor.org/stable/112670
null
null
Tables
34.625689
Biography
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Tables
[ 82.37738800048828, -18.39090919494629 ]
II . " On the Calculation of the Numerical Value of Euler 's Constant , which Professor Price , of Oxford , calls E. " By WILLIAM SHANKS , Esq. , Houghton-le-Spring , Durham . Communicated by the Rev. B. Price , F.R.S. Received March 28 , 1867 . In the year 1853 Dr. Rutherford , of the Royal Military Academy , Woolwich , sent a paper on the Computation of the value of T to the Royal Society , and the paper was published in the ' Proceedings ' of that learned body* . The value of 7r is there given to 607 decimals , the first 440 being the joint production of Dr. Rutherford and the author of this paper , and the remaining 167 decimals having been calculated by the present writer , for the accuracy of which he alone is responsible . Subsequently , the Astronomer Royal , G. B. Airy , Esq. , kindly presented the author 's paper on the Calculation of the value of e , the base ' of Napier 's logarithms , to upwards of 200 decimals ; the aforesaid paper also contained the Napierian logarithms of 2 , 3 , and 5 , as well as the modulus of the common system , all to upwards of 200 places of decimals . This paper was not , however , published , but deposited in the Archives of the Royal Society ; but an abstract , containing the numerical results , was printed in the 'Proceedings't . In a paper sent by the author to the Astronomer Royal , and forwarded by him to the Royal Society , will , the author believes , be found the reciprocal of the prime number 17389 , consisting of a circulating period of no less than 17388 decimals , the largest on record . Some few remarks are also given touching circulates generally , and the easiest modes of obtaining them . The writer now desires to supplement what he then did , by giving the 429 t Vol. vi . p. 397 . numerical value of Euler 's constant , which is largely employed in " Infinitesimal Calculus , " to a greater extent than has hitherto been found , and free from error . In Crelle 's Journal for 1860 , vol. Ix . p. 375 , M. Oettinger has contributed an article on Euler 's constant , and especially on " certain discrepancies " in the value given by former mathematical writers . Adopting the formula there employed , as being well adapted for the purpose , the writer of this paper has both corrected and extended what has been previously done ; and as very great care has been bestowed upon the calculations , so as to exclude error , he confidently believes that his results are , as far as they go , absolutely correct . He may remark that , since the separate values of n in the formula ( which , see below ) produce identical results as far as they go , and the higher the value of n the more nearly we can approximate to the value of the constant , we thus have sufficient proof afforded of the correctness of the value found when n is 10 , 20 , 50 , or 100 . If the writer can command sufficient leisure , he may resume the calculation by and by , and , making n 1000 , he may thus verify , as well as extend , the value of Euler 's constant given in this paper . The numbers 10 , 20 , 50 , 100 , 200 , and 1000 , especially 10 and its integral powers , are more easily handled than others , particularly in those terms of the formula which contain Bernoulli 's numbers . The harmonic progression is here " summed " much further than was requisite for finding E to 50 or.55 decimals ; but this was of some importance in ensuring correctness in the decimal expression of each of the higher terms of Soo and S200 . It may be observed that the numbers of decimal places in E , obtained from n being 10 , 20 , 50 , 100 , and 200 , are nearly proportional to 103 , 20 , 503 , 1003 and 200--a rather curious coincidence . The formula for Euler 's constant , employed by M. Oettinger , as above stated , isI B1 B2 B3 B4 Constant = Sn-loggn-~n-+ -2n-4n4+ 6n-8n+ ... * &c. , where Sn= 1+ +1+1+ -+. . , and B0 , B2 , B , &c. are Bernoulli 's numbers . n1+ + ... . -=2-928968253 1+4+4+ ... . . =3'59773 96571 43681 91148 37690 68908 38779 38367 10245 37897 60291 30827 89243 77995 58542 59259 83201 52499 71906 31865 55446 61736 61220 10084 85838 20720 04363 02603 48526 602 . 1++ ... ... -=3'81595 81777 53506 86913 48136 76474 73449 06181 89635 55401 83780 86220 32609 11027 77063 20242 32778 03544 32662 95332 52228 09675 62970 52433 81377 45056 57669 24455 54624 85197 30818 82894 77830 46585 03877 77968 87905 92007 71409 68243 + ( circulating period consists of 1584 decimal places ) . [ April 11 , 430 1+ + ... ... . I =4-49920 53383 29425 05756 04717 92964 76909 19706 01823 96745 38296 58902 43217 68318 06557 86735 78157 82663 88434 12900 97472 82033 55398 82942 03084 20093 94581 03200 90115 13091 15572 24477 64889 95794 59834 14243 62248 23530 45299 19591 + ( circulating period consists of 1,275,120 decimal places ) . 1++ ... . . 'T1=5-18737 75176 39620 26080 51176 75658 25315 79089 72126 70845 16531 76533 95658 72195 57532 55049 66056 87768 92312 04135 49921 06986 97779 79182 73403 18617 00828 94825 42444 49096 57618 56974 16326 13467 07313 21114 47132 49733 09103 51089 + ( circulating period consists of 39,419,059)680 decimal places ) . 1+2 ... ..2 . =5-87803 09481 21444 47605 73863 97130 86163 68374 00246 53027 30844 64971 94472 28783 30029 84018 15499 64301 86679 89238 37326 83211 85439 05911 76542 77855 27568 86559 30203 06049 25715 75389 22254 75748 47845 75246 64079 54805 61627 08837 + ( circulating period consists of 2,498,236,128,143,832,017,541,600 decimal places ) . The following value of Euler 's constant has been found from the respective sums given above , of the 10 , 20 , 50 , 100 , and 200 first terms of the Harmonic Progression : E or Eul . const . = 57721 56649 01532 86060 6 last term employed is24 . 10- ) E=-57721 56649 01532 86060 65120 900(last term is -24 4 ) E= 57721 56649 01532 86060 65120 90082 40243 1042 ( last term is+ B ) 53 540 0 ~46 ' E=-57'721 56649 01532 86060 65120 90082 40243 10421 59335 9 ( last term is-240 ) E= 57721 56649 01532 86060 65120 90082 40243 10421 59335 93995 35989 ( last term is+ 26.2 26.200s/ ) ' Certainly 50 decimals are correct , and probably 55 , in the value last given . March 2,1867 . Supplementary Paper to that of March 2 , 1867 , " On the Calculation of the Numerical Value of Euler 's Constant . " By WILLIAM SHANKS , Esq. , Houghton-le-Spring , Durham . Received April 9 , 1867 . When n=500 , we have l++ - ... ..---=6.79282 34299 90524 60298 92871 45367 97369 48198 13814 39680 91166 43088 89685 43566 23790 55049 24576 49403 73586 56039+ 1867 . ] 431 E=-57721 56649 01532 86060 65120 90082 40243 10421 59335 93995 35988 05771 53865 48677 ( last term -8.5002 ~28.5-28 ' When n= 1000 , we have 1+-+ +..T.Tlo=7.48547 08605 50344 91265 65182 79169 70883 36657 73626 74995 09599 34437 41184 50813+ E=-57721 56649 01532 86060 65120 59335 93995 35988 05772 02455 ( last term + 30000a ) 04333 90017 65216 76993 49165 20244 90082 40243 10421 61942 00508 15825 Hence we see that 54 decimal places are correct in the value of E ( n being 200 ) last given in the paper dated March 2 , 1867 , also that 59 decimals are correct in the value of E when n=500 . When n= 1000 , probably 65 decimals in the value of E are correct . When n=l , we readily find E=*57 ( last term _B ) . , =2 , , E=-57721 ( last term , =5 , , , E='57721 56649 015 ( last term +22.5BWhen n= 1 , E consists of 2 decimals . , , = 10 , , 21 decimals . = 100 , = 1000 , zn= 2 , 20 , 200 , n= 5 , 50 , 500 , , , 46 decimals . , , 65 decimals , probably . , , 5 decimals . , 28 decimals . , , 54 decimals . , , 13 decimals . , , 39 decimals . , , 59 decimals . From the above we may fairly infer that when n is increased in a geometrical ratio , the corresponding number of decimals obtained in the value of E increases only in something like an arithmetical one , and that probably from 50,000 to 100,000 terms in the Harmonic Progression would require to be summed in order to obtain 100 places of decimals in the value of E , Euler 's constant . 43
112671
3701662
On a Definite Method of Qualitative Analysis of Animal and Vegetable Colouring-Matters by Means of the Spectrum Microscope
433
455
1,866
15
Proceedings of the Royal Society of London
H. C. Sorby
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0101
null
proceedings
1,860
1,850
1,800
23
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11,970
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112671
10.1098/rspl.1866.0101
http://www.jstor.org/stable/112671
null
null
Chemistry 2
35.940071
Optics
28.102168
Chemistry
[ -35.95252227783203, -30.832866668701172 ]
III . " On a Definite Method of Qualitative Analysis of Animal and Vegetable Colouring-matters by means of the Spectrum Microscope . " By H. C. SoRBY , F.R.S. , & c , Received April 10 , 1867 . CONTENTS . PAGE 1 . History of the subject ... . 433 2 . Description of the Apparatus . 433 3 . Scale of Measurement. . 434 4 . Symbols used to describe Spectra 436 5 . General Remarks on Absorption , &c. ... ... .438 6 . Methods of Research. . 439 7 . Preparation of Vegetable Colours 439 8 . Examination of the Colours. . 440 9 . Reagents used ... ... 440 10 . Solvents ... . . 441 11 . Action of Acids and Alkalies. . 441 12 . General Absorption ... . 441 13 . Fading of Solutions ... . 443 14 . Absorption-bands ... 444 PAGE 15 . Action of Sulphite of Soda . 447 16 . Groups A , B , and C ... . 448 17 . Reagents used ... 449 18 . Separation of Colours into Groups , &c. ... . 449 19 . Order of the Experiments. . 450 20 . Division into Sub-Groups. . 451 21 . Individual Colours. . 452 22 . Mixed Colours. . 453 23 . Spectra with no Absorptionbands ... ... 453 24 . Yellow Colours ... . . 454 25 . Fading of Group C ... . 455 26 . Conclusion ... ... . . 455 1 . History . My attention was first directed to this subject by reading a report of Professor Stokes 's very excellent lecture at the Royal Institution , Friday , March 4th , 1864 . It immediately occurred to me that a spectroscope might be combined with a microscope , and employed to distinguish coloured minerals in thin sections of rocks and meteorites . I was soon led to examine many other coloured substances , and found that the instrument is more useful in connexion with qualitative analysis , when only very small quantities of material can be obtained . At first I employed the imperfect apparatus described in my Paper in the ' Quarterly Journal of Science ' * , but afterwards , along with Mr. Browning , I constructed that described in my Paper in the 'Popular Science Review ' t. For general purposes I do not think this could be much improved ; but for chemical testing it is much less fatiguing to use a binocular instrument . There were many difficulties to contend with , but at length I constructed one which appears to answer all the requirements of the case . 2 . Apparatus . I have an ordinary large binocular microscope , and use an object-glass of about three inches focal length , corrected for looking through glass an inch thick ; the lenses being at the top , so as to be as far as possible from the slit . This is placed at the focus , and between it and the lenses , at a distance of about half an inch from them , is a compound prism , composed of a rectangular prism of flint-glass , and two of crown-glass of about 61 ? , one at each end . This arrangement gives direct vision and a spectrum of the size most suitable for these inquiries , since a wide dispersion often makes the absorption-bands far too indistinct . In order to be able to compare two spectra side by side , a small rectangular prism is fixed over half the slit , and with the acute angle parallel to and just passing beyond it . This gives an admirable result , the only defect being that , when the spectra are in focus , their line of junction is some distance within it ; and therefore to correct , this I use a cylindrical lens of about two feet focal length , with its axis in the line of the slit , which can easily be fixed at such a distance between the slit and the prisms , as to bring the spectra and their line of contact to the same focus . In front of the slit , close to the small rectangular prism , is a stop with a circular opening , to shut out lateral light , and a small achromatic lens of about half an inch focal length , which gives a better field , and counteracts the effect of the concave surface of the liquid in the tubes used in the experiments , if they are not quite full . These are cut from barometer-tubes , having an internal diameter of about one-seventh of an inch , and an external diameter of about threesevenths of an inch . They are made half an inch long , ground flat at each end , and fixed with Canada balsam on slips of glass two inches long and about six-tenths of an inch wide , so that the centre of the tube is about one-fourth of an inch from one edge . By this arrangement the liquid may be examined through the length of the tube by laying the slip of glass flat on the stage of the microscope , or through the side of the tube , by placing the slip vertical and the tube horizontal . Cells of this size can be turned upside down and deposits removed without any liquid being lost ; and the upper surface of the liquid is sufficiently flat , even when inclined at a considerable angle . If requisite , small bits of thin glass can be laid on the top , which are held on by capillary attraction , or may be fastened with gold-size , if it be desirable to keep the solution for a longer time . When the depth of colour is too great in the line of the length of the cell , we can at once see what would be the effect of about one-fourth of the colour by turning it sideways ; and thus we can save much time , and quickly ascertain what strength of solution would give the best result . Very frequently we obtain an excellent spectrum in one direction with one reagent , and in the other with another , without further trouble . I have constructed a small stage , too complicated to describe in writing , which enables me at once to examine solutions in two such tubes , either endways or sideways , and compare their spectra side by side , or to use test-tubes , or to fix the small apparatus which I have contrived for accurately measuring the spectra . This is of such great importance in these inquiries that I must describe it in some detail . 3 . Scale of Measurement . It consists of two small Nicol 's prisms , and an intermediate plate of quartz . If white light , passing through two such prisms , without the plate of quartz , be examined with the spectrum-microscope , it of course gives an ordinary continuous spectrum ; but if we place between the prisms a thick plate of quartz or selenite , with its axis at 45 ? to the plane of polarization , though no difference can be seen in the light with the naked eye , the spectrum is entirely changed . The light is still white , but it is made up of alternate black and coloured bands , evenly distributed over the whole spectrum . The number of these depends on the thickness of the depolarizing plate , so that we may have , if we please , almost innumerable fine black lines , or fewer , broader bands , black in the centre and shaded off at each side . These facts are of course easily explained by the interference of waves . It would , I think , be impossible to have a more convenient or suitable scale for measuring the spectra of coloured solids and liquids . If we use a micrometer in the eyepiece , an alteration in the width of the slit modifies the readings , and the least movement of the apparatus may lead to error , whereas this scale is not open to either objection . Besides this , the unequal dispersion of the spectrum makes the blue end too broad , so that a given width , as measured with a micrometer in the eyepiece , is not of the same optical value as the same width in the red . The divisions in the interference-spectrum bear , on the contrary , the same relation to the length of the waves of light in all parts of the spectrum , and no want of adjustment in the instrument alters their position . As will be seen from the drawing ( fig. 1 ) , the unequal dispersion makes the distance betweeen the bands in the blue about twice as great as in the red . The perfection of a spectrum would be one in which they were all at equal intervals ; but possibly no such uniform dispersion could be produced . By having a direct-vision prism , composed of one of flint-glass of 60 ? , and two of crown-glass of suitable angle , we can place it over the eyepiece , and may diminish the dispersion at the blue end , or increase that at the red end , by turning it in one position or the other , and thus see either end to the greatest advantage . It is , of course , very easy to draw spectra on this principle , and give all parts equal prominence , and not an unduly compressed red , and an unduly expanded blue end . Thus drawn , the spectra are far more uniform in many of their characters , and some general laws are at once apparent that otherwise might have been entirely overlooked ; and on this account I shall adopt this system in those figured in this paper . It is , in fact , merely representing the actual measurements by drawings , without being at the trouble of distorting them , so as to be like naturally distorted spectra . Since the number of divisions depends on the thickness of the interference-plate , it became necessary to decide what number should be adopted . At first 1 thought that ten would be most suitable ; but , on trying , it appeared to me too few for practical work . Twenty is too many , since it then becomes extremely difficult to count them . Twelve is as many as can be easily counted ; it is a number easily remembered , gives sufficient accuracy , and has a variety of other advantages . With twelve divisions the sodium-line D comes very accurately at 3L ; and thus , by adjusting the plate so that a bright sodium-line is hid in the centre of the band , when the Nicol 's prisms are crossed , it is accurately at 34 , when they are arranged parallel , so as to give a wider field . The general character of the scale will be best understood from the following figure , in which I have 22 435 numbered the bands , and given below the principal Fraunhofer lines . 012345678 10 11 12 Red end . T lZ iI| Blue end . ReddFig . 1.yV i ABC D Eb FG The centre of the bands is black , and they are shaded off gradually at each side , so that the shaded part is about equal to the intermediate bright spaces . Taking , then , the centres of the black bands as 1 , 2 , 3 , &c. , the centres of the bright spaces are 1 , 2 ; , 3 , &c. , the lower edges of each , 13 , &c. , and the upper 14 , 24 , &c. We can easily divide these quarters into eighths by the eye ; and this is as near as is required in the subject before us , and corresponds as nearly as possible to -1I part of the whole spectrum , visible under ordinary circumstances by gaslight and daylight . Absorption-bands at the red end are best seen by lamplight , and those at the blue end by daylight . On this scale the position of some of the principal lines of the solar spectrum is about as follows : A ... . n B ... . 1 C ... . 2 D ... . 3 E ... .5 ? b6 ... . 63 F ... .7 G ... .10 At first I used plates of selenite , which are easily prepared , because they can be split to nearly the requisite thickness with parallel faces ; but I found that its depolarizing power varies so much with the temperature , that even the ordinary atmospheric changes alter the position of the bands . Quartz cut parallel to the principal axis of the crystal is so slightly affected in this manner , as not to be open to this objection , but is prepared with far greater difficulty . The sides should be perfectly parallel , and the thickness about ? 043 inch , and gradually polished down with rouge until the sodium-line is seen in its proper place . This must be done carefully , since a difference of T--1 inch in thickness would make it decidedly incorrect . I have prepared such plates , corresponding to my own , and placed them in the hands of Mr. Browning and of Messrs. Becks , so that any one wishing to adopt a similar scale may be able to do so more accurately . The two Nicol 's prisms and the intervening plate are mounted in a tube and attached to a piece of brass in such a manner that the centre of the aperture exactly corresponds to the centre of any of the cells used in the experiments , which are all made to correspond in such a manner that any of them , or this apparatus , may be placed on the stage and be in the proper place withlout further adjustment , which , of course , saves much time and trouble . 4 . Symbols used to describe Spectra . In order to describe spectra in my note-book or in print , I have devised a simple notation , employing types in constant use . Instead of writing an . account of this system , I here give a printed illustration , which will show that by this means it is easy to give in a single line all the essential particulars which would otherwise require a long and tedious description , or a number of drawings and woodcuts . Without some such method of measuring and recording spectra it would be almost impossible to carry on extensive inquiries . The intensity of the absorption is expressed by the following types : Not at all shaded Blank space . Very slightly shaded ... Dots with wide spaces . Decidedly shaded ... Dots closer together . More shaded ... Very close dots . Strongly shaded , but so that a trace 1 Three p of colour is still seenThree hyphens close . Still darker Single dash . Nearly black Double dash . Except when specially requisite , only the symbols ... -are employed for the sake of simplicity , and then as signs of the relative , rather than of the absolute , amount of absorption ; and it is assumed that there is a gradual shading off from one tint to the other , unless the contrary is expressed . This is done by means of a small vertical line over the figure ( see No. 11 ) , which shows that there is a well-marked division between them . Definite narrow absorption-bands are indicated by * printed over their centre . This will be better understood by a description of the spectrum of deoxidized hematin . 4 -5 5i 6.C 9 1011The following examples will show how simple or more complicated spectra may thus readily be printed and compared . I have chosen solutions of similar tint , in order to show that the spectra of those of nearly the same colour may be very different , or , if analogous , may differ in details easily expressed by the symbols . The colour of each is given after the name . Nos. 1 , 8 , 9 , 10 , 11 , 12 , and 13 can be kept for a long time sealed up in tubes , and the rest are easily prepared . I have in all cases chosen that strength of solution which gives either the most characteristic spectra , or those best suited for comparison with other allied colours . ; 1 . Cudbear in alum ( Pin k ) 3. . 8 11 . 2 . Colour of Elder berries with ] citric acid . ( Red Pink ) t pead . 1 4 . of ammonia . ( Pink ) 4 . 5 ... ..0-8 4 . Logwood , with bicarbonate of ammonia . ( Pink ) J3 5 ... . . 7 437 The next four are spectra of blood , produced by the successive addition of the various reagents , as in detecting fresh stains . ** 5 . Fresh Blood . ( Pale Scarlet ) 34 44 4 54 7. . 8 96 . Citric Acid then added . * ( Pale Brown ) f. . 2$ 4 ... 8 ... 9 --107 . Ammonia then added . ** ( Pale Brown ) 3. . 4 47 ... 5 7. . 8--108 . Deoxidized hamatin , from blood* * stain 2 years old . ( Pink ) 4 -5 54 ... 64 9. . 10 --11With these may be compared the two spectra which more nearly resemble those produced by blood than any I have yet seen . 9 . Cochineal in alum . ( Pink ) 3 44. . 5 --6. . 7** 10 . Alkanet-root in alum . ( Pink ) 31 44 5 ... 54 The following spectra of compounds derived from chlorophyll are as complicated as any I have met with . 11 . Normal chlorophyll in alcohol . 7*2167 ( Deep Green ) J2 6-3. . -12 . Ditto , as decompos- ) ed by acids , or as *** found in some leaves . 1--24 2 -3 4 ... 5 --5 ... 6 784- . -9-(Olive Green ) J 13 . Ditto , as decompos- ) ed by caustic potash , and then by hydro[ ** * same in a different condition ; whereas , if two spectra agree , they may be the same substance , or two distinct substances , whose different actions are made equal by particular circumstances . As an illustration , we may refer to a short string , which may give the same note as a longer whose tension is greater . For this reason we should be careful not to rely too much on one spectrum . If , however , we can produce some great physical change in both substances , and still their spectra remain the same under equal conditions , and if this occur uniformly in several different changes , we may conclude that they are identical . Hence the value of the various reagents named below . Many excellent illustrations of these principles could easily be given . 6 . General Method of Experiments . Since the spectrum-microscope enables us to use very small quantities , it appeared desirable to adopt such a method of research as would enable us to take full advantage of this circumstance , and to avoid as much as possible previous chemical manipulations . On this account I shall say nothing about modified chemical methods , which may , of course , be also employed when sufficient material is at command . My aim has been to contrive a special system of qualitative analysis of coloured substances applicable to minute quantities , and as independent of general chemistry as the blowpipe method is in the case of minerals . *I may here say that in some very important practical applications to the detection of blood-stains not above 1-o of a grain was at disposal , and yet perfectly satisfactory results were obtained . I was led to study the colouring-matters of flowers , leaves , fruits , woods , and roots , because it appeared a most admirable field of inquiry to teach the general principles of the subject . The colours being so various , and occurring under such complicated conditions , I thought that if methods could be devised to distinguish those that are dissimilar and to prove the identity of those that are alike , even when mixed with coloured impurities , such principles could easily be applied to other inquiries . If the question were merely to distinguish or compare absolutely pure colouring-matters , there would be little or no difficulty ; but it appeared to me that one great value of the method would be to be able to apply it at once to very impure and mixed materials . In such cases mere colour is of very secondary importance , since that may be totally changed by a very small amount of impurity . 7 . Preparation of Colours . If the petals , leaves , &c. of plants be crushed in water , it very commonly happens that the colour is rapidly decomposed and no clear solution can be obtained ; but if crushed in a moderate quantity of spirits of wine , and the solution squeezed out , filtered , and evaporated to dryness at a gentle heat , the colouring-matter does not decompose , even 1867 . ] 439 when redissolved in water and filtered to remove anything not soluble in that liquid . This clear solution should then be evaporated to dryness at a gentle heat in a small saucer , and kept dry ; for then the colours often imdergo no important change in the course of many months , whereas , when kept dissolved in water or alcohol , they may quickly decompose . I have thus prepared the colouring-matter of above a hundred different vegetable substances , some of which have become entirely changed , but a large number are apparently still unaltered . I have also kept a number of colours , sealed up in glass tubes , ready for direct examination , dissolved in alcohol , in strong syrup , or in alum . Many have decomposed , but many have kept perfectly well , or have merely faded , and still give excellent spectra after above a year . I have also prepared and kept in the same manner some animal colouring-matters , but comparatively few . 8 . Method of examination . The coloured substances are examined , when dissolved in water , alcohol , or other solvent , in the small glass cells already described , and the various reagents are added and mixed by means of a moderately stout platinum wire , flattened at one end and turned up square , like a little hoe . I have made many experiments in order to ascertain what reagents are most serviceable in developing characteristic spectra , and have at length concluded that for general purposes the following are the most convenient . Those which are solid are best kept in small bottles as coarse powder , and added to the small cells in a solid state , so that the quantity used may be more readily known . 9 . Reagents . Hydrochloric acid . Citric acid . Benzoic acid . Boracic acid . Bicarbonate of ammonia . Carbonate of soda . Diluted solution of ammonia . Caustic potash . Sulphite of soda . Sulphate of protoxide of iron . Alum . Iodine dissolved in alcohol . Bromine dissolved in water . Solution of hypochlorite of soda . Permanganate of potash . This list might of course be very much extended , if we were to include such reagents as may be used in separating or decomposing colours by the ordinary chemical methods . In describing the effect of those named in this list , I feel that I could not avoid mentioning some well-known facts without breaking the thread of my argument ; and therefore I trust it may not be thought out of place if I give a general account of the whole from the particular point of view required by the subject more especially before us . The action of many reagents is so intimately related to different parts of the spectrum , as to show that there must be some connexion between socalled chemical reactions and optical phenomena . Not that their effect is absolutely the same in the case of all coloured substances , but generally only the extent differs , whilst the character of the change is uniform ; unless , indeed , decomposition take place ; and even then it has a tendency to conform to a general law . 10 . Solvents . Water and alcohol are the most useful solvents , and the spectra of the two solutions of the same substance often differ most strikingly ; in fact they often behave in other respects as if they were solutions of different substances . Sometimes the spectra are absolutely identical , but often wellmarked narrow absorption-bands are seen in the alcoholic solution , where they are almost , or quite , invisible in the aqueous . Very commonly the same bands are seen in both , but not exactly in the same place , alcohol sometimes raising them to a higher part of the spectrum , and sometimes depressing them . Occasionally the spectrum of the dry material is like that of the alcoholic solution , and unlike that of the aqueous , as if the difference were due to the presence of water , but in other cases it is unlike both . At all events the facts clearly show that a solvent has a most important action on the ultimate particles of the substance in solution , since it may produce a greater change in optical phenomena than even chemical combination . Undistilled hard water may act like a weak alkali . 11 . Acids and Alkalies . As far as optical phenomena are concerned , there is no absolute division between acids and alkalies ; for we have every connecting link from the strongest acids to the strongest alkalies . In order to understand their action , it is most essential to distinguish between what may be called " general absorption " and " local absorption-bands . " There may , perhaps , be no absolute line of division , but when seen to advantage they are affected in such a different manner that it is desirable to treat of each separately . 12 . General Absorption . As a good example of simple general absorption , we may take the crimson colouring-matter of the commonWallflower ( Cheiranthus Cheiri ) , which is soluble in water , and , along with a yellow only soluble in alcohol , gives rise to the varied colours of the flowers . When neutral , it is crimson ... . 2a- ... .7 10. . 11--With ammonia , fine green ... . 1--4 ? -..6 7. . 8-9With citric acid , deep pink ... . 3.4 6-..8k 11 ... These facts will be better understood by means of the following drawing : Red end . Fig. 2 . Blue end . 1 . Citric acid ... ll . 2 . Neutral. . l'j 3 . Ammonia . l1 il ' Whence it will be seen that citric acid raises and greatly increases the central absorption , and ammonia lowers and also increases it . At the same time the absorption at the extreme blue end of the spectrum is raised by the acid almost to beyond the range of vision , but lowered to the centre of the spectrum by ammonia . Acids and alkalies of intermediate character , as , for example , boracic acid and bicarbonate of ammonia , produce intermediate effects . These well-known phenomena may be looked upon as typical of acids and alkalies , but the extent of their action varies for each particular colouring-matter , so that in some cases it is slight , and sometimes neither acids nor alkalies produce any effect . Their relative action on the central and upper absorption also varies very greatly in different colours . If there is no general absorption in the centre of the spectrum , when the colour is neutral , but only an absorption at the blue end , acids and alkalies act on it in precisely the same manner as on the absorption at the blue end in the case just described , raising or lowering it to an extent varying greatly according to the substance ; and the same may be said of any general absorption at the red end . The reverse certainly occurs when anl acid is added to chromate of potash , or excess of ammonia to a salt of copper ; and , according to Stokes ( Phil. Trans. 1862 , p. 609 ) , alkaloid bases usually show this reverse action . It may depend on the different properties of two distinct compounds , which does not appear to be the cause of the phenomena now under consideration . In the case of all the vegetable colouring-matters which I have examined , the tendency of acids is to raise , and of alkalies to depress , the general absorption in each part of the spectrum ; the extent of this action depending on the strength and quantity of the reagents , and on the nature of each colouring-matter ; and thus we have a general rule , and not several , as commonly adopted by chemists , each of very limited application ; for instance , that vegetable blues are turned red by acids , and green by alkalies ; and that vegetable yellows are reddened by alkalies . I may here remark that some colours would appear to be exceptions , if we did not remember that waves of light , or waves analogous to them , exist beyond the visible spectrum . Thus , for example , when alkalies are added to the yellow solution of Brazilwood ( Ccesalpinia crista ) , it is changed to pink , the absorption being so much lowered that the blues are transmitted ; this clear space corresponding to what was probably a clear space beyond the blues visible under ordinary circumstances , but which would perhaps be seen , if examined in the manner described by Stokes in his paper on the long spectrum of electric light* . 13 . Fading of Solutions . One striking peculiarity in the action of acids on the solutions of many vegetable colours is , that , when they are in a particular state of acidity , they fade to nearly or quite colourless , without there being any decomposition . This is especially the case with pink colours dissolved in alcohol . It occurs slightly with blue colours , and little , if at all , with yellows . The aqueous solutions change much more slowly , but more and more rapidly the more they are diluted ; and frequently attain a permanent depth of colour , which is dark or pale according as the solution is strong or dilute . Of course I here allude to the effect of the same total amount of colour , and not to the different effect of the same quantity of a strong or dilute solution . The alcoholic solutions obtained direct from the flowers often fade so rapidly , and become so nearly colourless , that any one might easily fancy that all the colour was lost by decomposition ; and an evaporating dish containing it , might appear merely filled with brownish alcohol , and yet on evaporation the whole dish might be covered with a fine deep colour . The same change may occur over and over again , the deep-coloured solution first obtained soon fading , and the colour being restored by subsequent evaporation . When such a colour is dissolved in a little water and added to alcohol in an experiment tube , the colour may at first be very deep , but may fade so rapidly that there is scarcely time to observe the spectrum before it passes into that molecular state which does not absorb any of the rays of light . The colouring-matter of the flowers of the red Salvia ( S. splendens ) is an excellent example . Neutral solutions do not undergo this rapid change ; a different condition of acidity is requisite for different colouring-matters ; and some do not change at all . A large excess of citric acid very often restores the intensity of the colour ; and usually the absorption-bands are seen to the greatest advantage when the solution is in that state which rapidly fades ; and by adding too much colour and watching whilst it fades , they may be seen and measured when at their best . This fading of a darkcoloured solution must not be confounded with the change which takes . , place on diluting some salts , as described by Dr. Gladstone in his paper on that subjectt . 14 . Absorption-bands . Though acids and alkalies thus , to a greater or less extent , alter the position of the general absorption , they act very differently on the special , local absorption to which it is very convenient to restrict the term " absorption-bands . " Since I shall often have to speak of their being at equal intervals , it would be well to say that I have found it convenient to construct a wedge-shaped piece of quartz , cut parallel to the axis of the crystal , and to use it along with two Nicol 's prisms in such a manner that the spectrum may be divided into any requisite number of equal portions , by interference-bands situated in any requisite position . This of course avoids the errors which so often happen when we compare together measurements that cannot be made with very great accuracy . As an excellent illustration I select the colouring-matter of Alkanet-root ( Anchusa tinctoria ) . It is insoluble in water , but is easily dissolved by alcohol , even when much diluted with water , and gives a clear pink solution . The spectrum is nearly the same when the colour is dissolved in absolute alcohol , as when much water is present , only each of the absorption-bands is situated rather higher . Thus , taking the centres of the bands , we haveb . c. d. Absolute alcohol ... ... ... ... ... . . 4 5 & 7 Very dilute alcohol ... ... ... ... ... . 453 71 The general spectrum of the solution in dilute alcohol will be best understood from the following figure , No. 1:Fig . 3 . Red end . abed Blue end . 1 . Neutral or somewhat acid . 2 . A little carbonate of soda . 3 . More carbonate of soda . ab Acids produce no important change , and the effect of alkalies is best seen by gradually adding carbonate of soda . This alters the colour to a more and more blue-purple , and the spectrum is changed in the manner shown in fig. 3 . The three bands seen in the neutral solution may be referred to as b , c , and d , and their centres occur at equal intervals of about 1 . When enough carbonate of soda has been added to make it slightly purple , a fourth band , a , makes its appearance , separated from b by the same equal interval of 1 , whilst the other bands remain in the same position as at first , only modified in intensity . The band a becomes darker and darker as more carbonate is added , until , when the solution is a fine purple , it is as dark as the others ( see No. 2 ) ; and on adding ? more carbonate it becomes still darker , and the bands c and d more faint , until the solution is a purple-blue ; and the spectrum has only the two wellmarked bands a and b , shown by No. 3 . The bright blue colouring-matter of the flowers of Lobelia speciosa gives , when neutral , almost exactly the same spectrum as that of Alkanet-root when alkaline , No. 3 , having two well-marked absorptionbands , whose centres are at 24 and 44 ; and on adding carbonate of soda , the upper one is gradually removed , and the centre of the lower is depressed to near 2 } . More or less similar results occur in the case of many other blue colouring-matters ; and on adding a slight excess of acid the general absorption is raised , and other bands may be developed higher up , at equal intervals ; but when a large excess has been added , they are lost in a strong general absorption . Too strong an alkali may also destroy narrow bands in a similar manner , as is well seen in the case of Brazilwood . The neutral aqueous solution shows an absorption-band , made far more distinct by the addition of bicarbonate of ammonia , which makes it pink and very fluorescent . The spectrum is then 44 54 7 ; but on adding excess of ammonia the solution ceases to be fluorescent , the narrow absorption-band is lost , and the spectrum becomes 31 . 4--8 -. . 9- . Ammonia does not produce this effect when the colour is dissolved in alcohol , the solution remaining fluorescent and still giving the narrow band ; and , as a general rule , that solvent greatly impedes or entirely prevents such changes , and on this account almost invariably shows absorption-bands to the greatest advantage . We therefore see from the above examples that the absorption follows the general rule , and is raised by acids , and depressed by alkalies ; but this only applies to the absorption when viewed as a whole , and not to the separate bands ; for those reagents change their intensity , but not their position . In some cases , indeed , their position is slightly altered , so that perhaps it would be more correct to say that acids and alkalies may raise and depress the general absorption to an extent equal to a considerable fraction of its own great breadth ; whereas they either do not change the position of narrow absorption-bands , or merely raise and depress them by a fraction of their own narrow width . It is their very definite position that makes them so useful in this method of analysis . Unfortunately I have not hitherto been able to find a sufficient number of colouring-matters giving rise to three or more well-marked absorptionbands , to warrant a general conclusion ; and therefore it is perhaps premature to conclude that their centres always occur at equal intervals . At 4415 the same time it is certainly a very common fact . When the maximum point of transparancy occurs between the different bands , there may be , as it were , a double interval ; but then , sometimes , even this missing band may be seen under favourable conditions . A difference in the general absorption may also somewhat alter the apparent position of a band , if it is strongly shaded on one side , and not on the other ; and the presence of impurities may also modify the results , so that absolute accuracy cannot be expected in all cases ; and occasionally very narrow bands occur which appear to belong to a second system . It must be borne in mind that the bands are equidistant , only when measured by means of the interferencespectrum . Thus , in the case of Alkanet-root , when measured with a micrometer , instead of the intervals a to b and c to d being equal , they are related to one another about as 1 and 2 , and thus the general law is entirely obscured . If subsequent research should prove that the bands are normally at equal intervals , it will be a fact of great value in deciding whether certain spectra are or are not due to a mixture of colours ; since , if a band occurred at a perfectly unequal interval , it would show that there must be at least two substances . Even in the present state of our knowledge , any inequality should make us carefully search for some satisfactory reason for such a divergence from a common rule . My meaning will be better understood from the following examples . If a little of the colour of Brazil-wood be added to the solution of Alkanetroot , the bands are not altered , and are seen at 44 , 54 , and 7 ; but a little bicarbonate of ammonia developes a well-marked band , whose centre is at 5 ? , and therefore at an interval of 1 , instead of 1I . The same is also well seen in the case of a mixed solution of Brazil-wood and blue Lobelia . I therefore argue that if an unknown substance gave rise to similar spectra , with bands at unequal intervals , we ought strongly to suspect that it was either naturally composite , or that some new compound had been formed by decomposition . As a very good illustration I may refer to the product of the action of acids on chlorophyll . The band in the red is not at an equal interval ; but , on carefil examination , it is seen to be made up of two bands , the upper of which is at an equal interval . I was not aware that these were due to two different substances , but was led to think it very probable ; and Professor Stokes informs me that he has proved it to be the case . As an illustration of another kind of exception , I refer to the colouringmatter of the pink Stock ( Matthiola annua ) . The aqueous solution shows two bands , whose centres are at about 3| and 54 ; and on adding ammonia the upper is removed , and the lower depressed to 34 . In spirit of wine they are at 4 and 5k , and ammonia developes a third at 3 , which are not equal intervals . However , if absolute alcohol be used , the bands are at 23 , 44 , and 5 ! , which are equal intervals ; and thus we see that the abnormal inequality is due to the presence of water , which causes the spectrum to be as if due to a mixture of two colours , when in reality it is the same colour dissolved in two solvents . In spectra showing one absorption-band , there is very commonly a general absorption , extending from it towards the blue end ; whereas it so seldom extends towards the red end that it is doubtful if it ever occurs in substances , undoubtedly not a mixture of two colours . It can , however , so easily occur in mixed colours , that any substance giving rise to such a spectrum is probably a mixture . Many illustrations might be given , but I will select Brazil-wood , and the same artificially mixed with the colour of beet-root . Adding bicarbonate of ammonia to both , we haveBrazil-wood alone ... ... 4-5 ... 7 Brazil-wood and beet-root 3 ... 4--53 ... ..8 Here , then , the shading below the absorption-band from 3k to 45 is evidence of the second colour , and if such a mixture had occurred naturally its mixed character might easily have been overlooked . I have found many cases similar to this , and had proved that they were mixtures , before I was aware that the spectra indicated it . If these very common facts turn out to be general laws , we might thus detect at once the presence of as many as three different substances , or at all events might learn what further examination was desirable . 15 . Sulphite of Soda . Sulphite of soda is a most valuable reagent , and its action very remarkable . It enables us to divide colours into three groups , according as it produces a change in an ammoniacal , or acid solution , or in neither . The action is related in a very simple manner to the spectra . Having added an excess of ammonia , there may be a well-marked broad absorption over more or less of the red , orange , yellow , and upper green ; and above this a clear transparentspace , limited by a variable amount of absorption , extending downwards from the extreme blue . Fig. 2 will illustrate my meaning . In the case of one group of colours , the addition of sulphite of soda almost immediately removes the detached , broad absorption in the lower part of the spectrum , but leaves that at the blue end quite unchanged , or only slightly modified by the solution being made more alkaline . If , then , as in the case of magenta , there is no absorption at the blue end , sulphite of soda makes the solution quite colourless ; whereas if the blues are absorbed , as in the case of the ammoniacal solutions of the colour of red roses , and some species of Dianthus , it changes the colour from green to yellow . If the absorption extends continuously down from the extreme blue to the orange , as often happens when ammonia is added to yellow colours , sulphite of soda produces no change . It is only when there is a more or less perfect division between the upper and lower absorption , that it has any effect ; and then it simply and entirely removes the lower absorption . Some colours are changed immediately , even when a very small quantity of sulphite is added ; but others require more and change gradually , though still very soon . 447 16 . Groups A , B , and C. Colours which are thus altered when the solution is ammoniacal , constitute my group A. Frequently , however , sulphite of soda does not remove the detached absorption when excess of ammonia is present , but does so when there is an excess of citric acid . These constitute my group B. AS in the other group , any absorption which extends continuously from the extreme blue end is not altered , but the detached absorption in the green is almost immediately removed ; and therefore a deep pink or red solution may at once become quite colourless , or only a very pale yellow ; and in many cases this residual colour is due to some yellow colouring-matter mixed with the other . I have never seen a colour which was changed by sulphite when alkaline , and not when acid ; and thus citric acid never restores the colour when it is added to the changed ammoniacal solution . Excess of ammonia usually restores the faded acid solution to nearly the original colour , and it is therefore not a case of actual decomposition , but merely the result of some remarkable molecular change . A third group of colours consists of those which are not almost immediately changed by sulphite of soda , when either alkaline or acid ; and these I call group C. Some of them may fade on keeping several hours , and some do not fade even in several days , but they cannot thus be divided into two definite groups . When thus faded , ammonia does not restore the colour ; and therefore it is evidently the effect of decomposition , and not like the mere molecular change met with in group B. On the whole , the groups A , B , and C are remarkably distinct . There are , indeed , a few cases where the change takes place somewhat slowly ; and a few scarlet colours do not show very distinctly the characteristic peculiarities of either B or C ; but there are other very strong reasons for believing that some of these are really mixtures of different groups . Even if it should be found that perfectly simple colouring-matters may have , as it were , intermediate characters , such appear to be so rare that practically they may be classed with mixtures , until some reason be found for classing them together as exceptions . These reactions of sulphite of soda are so much interfered with by the presence of alcohol , that it should never be employed as a solvent , unless the substance is insoluble in water ; and then it should be diluted as much as possible , since the ordinary spirit of wine with an equal quantity of water is the extreme strength admissible , and even that very much delays the reaction . The effect of various other reagents is also sometimes very different , according to the nature of the solvent . The three groups A , B , and C differ in other particulars . It is easy to change A or B into C by various reagents which produce decomposition , but I do not know a case where C can be changed into A or B. Caustic alkalies usually soon decompose colours belonging to group A , when dissolved in water , but act slowly on those of groups B and C. Usually colours of group C are far more permanent than those of groups A and B , and to it belong most of the vegetable colours used in dyeing , and nearly all yellows . 17 . Other Reagents . Boracic Acid.-The chief value of this reagent is that it gives nearly the same spectrum as that of a neutral solution when added after the addition of a slight excess of ammonia . It should therefore be well fused in a platinum crucible and recrystallized , so as to be quite free from any stronger acid . Sulphate of Tron.-Sulphate of the protoxide of iron is chiefly useful as a deoxidizing agent , in the case of blood and a few analogous substances , taking care to have citric acid present to prevent the precipitation of the oxide by ammonia * . Alum.-Alum has a remarkable influence on some colours , and it has the property of gradually restoring many after they have passed into the faded modification . Many colours also may be kept for a long time dissolved in a strong solution , sealed up in tubes ; and it is occasionally an excellent solvent for substances insoluble in either water or alcohol . The chief objection to it as a reagent is that the spectra are so much influenced by the presence of ammonia , even when neutralized by an acid , that it is almost impossible to compare together different substances under exactly the same conditions . Iodine and Bromine.-Iodine dissolved in alcohol , and bromine in water , are useful in producing decompositions , which may differ very considerably in colours which are otherwise very similar ; as , for example , the yellow colouring-matters of the root of rhubarb and of turmeric . The iodine or bromine should be added in sufficient quantity , and then ammonia used to remove the excess , and thus avoid the effect of their own colour . The solution may then be made acid with citric acid , and should in both cases be compared with another tube to which no iodine or bromine has been added . Hypochlorite of Soda.-This reagent , with or without the addition of citric acid , is sometimes useful , as for instance in detecting the adulteration of rhubarb with turmeric ; but generally its action is too powerful and too uniform . Permanganate of Potash.-This also usually acts too powerfully on colouring-matters . The excess can easily be removed by sulphite of soda , which makes an alkaline solution pale yellow , but an acid solution quite colourless . 18 . Grouping of Colours . Having now considered some of the chief peculiarities of the most useful reagents , I proceed to describe what appears to me to be the most convenient method of dividing colouring-matters into groups and subgroups , so as to enable us to ascertain the nature of any particular substance under examination . The number of distinct coloured compounds met with in different plants is so great , that some such classification is imperative . In the first place , we cannot do better than divide them according as they are soluble in water or alcohol . This may be looked upon as a chemical division , and is very useful in practice . ThusSoluble in water and not precipitated by alcohol ... . Division 1 . Soluble in water and precipitated by alcohol ... . . , 2 . Insoluble in water but soluble in alcohol ... ... ... . 3 . Insoluble both in water and alcohol ... ... ... ... ... . . 4 . Of course cases occur which cannot be unhesitatingly classed with any one of these ; but they often form good practical divisions , and necessarily modify the methods requisite for further examination . 19 . Method and Order of Experiment . If a colour belongs to division 1 , a small quantity , sufficient for three or four experiments , should be exposed to the vapour of ammonia in a watch-glass , until there is certainly no longer any free acid , and then gently evaporated , so that all excess of ammonia may be lost . If not'thus made neutral we might be entirely misled ; for some pink colours are blues . reddened by an acid . A small quantity should then be dissolved in water in one of the small experiment-tubes and the spectrum observed . If too little colour has been added to give the characteristic spectrum , more should be introduced ; but if any part is entirely absorbed , the cell should be turned sideways , in order to see whether or no some narrow absorptionband occurs there ; and then it may be desirable to remove some of the solution , and fill up the cell with water . As a general rule , so much colour should be added as to make the darkest part of the spectrum decidedly shaded , but yet not so black as to hide any narrow bands ; and if any occur , the solution should be made of such a strength as to show them to the greatest advantage . This can easily be done , after a little practice , and is made much easier by being able to turn the tubes sideways . Having noted the spectrum of the neutral solution , a very small quantity of ammonia should be added , and then a decided excess , the spectra being examined to see if there be any difference ; for this is very often the case and very important facts may be overlooked if too great an excess be added at first . The addition of a small bit of sulphite of soda then shows at once whether or no a colour belonging to group A is present ; and on adding excess of citric acid we may also determine whether it chiefly belongs to groups B or C. Ammonia should then be added in excess , which may or may not restore it to the same state as before the addition of the acid . To another portion of colour carbonate of soda should be added , and then excess of citric acid , both spectra being carefully observed ; and finally sulphite of soda , which definitely shows whether or no there is any other colour than one belonging to group C. Combining the results of the two sets of experiments , we may decide whether it belongs to groups A , B , or C , or is a mixture of any of them . If the substance is insoluble in water but soluble in alcohol , the same experiments should be made , only we must add the colour dissolved in alcohol to as much water as can be used without making the solution turbid , and must remember how much the presence of alcohol may interfere with the action of some of the reagents . Another portion of the neutral colour should then be dissolved in as strong alcohol as will give a clear solution , and ammonia , benzoic acid , a little citric acid , and much of it added one after the other ; and all the spectra carefully observed , as well as any other facts which may present themselves . By thus using three separate quantities of colour , and adding reagents one after the other , we may obtain about a dozen spectra , which may differ from one another in important particulars , or in some few cases may be all alike . The experiments are so easily made , that the whole series of twelve spectra may be seen in the space of five minutes ; and the total quantity of material need not in some cases be more than T ? ToJ of a grain . The facts thus learned may show that for particular practical purposes some different method could be employed with advantage , and that only one or two simple experiments are needed . For example , suspected blood-stains should be treated in an entirely different manner , as described in my Paper on that subject ; and in examining dark-coloured wines , in order to form some opinion of their age from the relative quantity of the colour belonging to group C , gradually formed by the alteration of the original colouringmatter of the grape belonging to group B , it is only requisite to observe the effect of sulphite of soda after the addition of citric acid . It would , however , extend this Paper beyond the limits I have prescribed to myself ; if I were to enter into practical applications , and I shall therefore merely give a description of a convenient method of grouping the various colours . 20 . Subgroups . Since the narrow absorption-bands are decidedly the most important means of identification , it appears to me that we cannot do better than adopt subdivisions founded on their number . We may thus divide each group A , B , and C into subgroups , in which the neutral aqueous solutions exhibit 0 , 1 , 2 , 3 , &c. decided absorption-bands . Sometimes one of them may be so obscure that we may hesitate whether it should be counted or not ; but practically this is no very serious objection , if we decide to reckon only distinct bands , and to look on the fainter as important merely in identifying individual colours . If no absorption-band can be seen in the neutral solution , we may take into account those seen when more or less ammonia is added ; and if none occur in either case , we may make use of those seen in the alcoholic solution when neutral , and after the addition of ammonia . Whenever in this order of experiments the solution gives * Quarterly Journal of Science , vol. ii . p. 205 . 2r2 451 any decided absorption-band the subgroup is determined ; and it is only when none has been produced that the process must be carried further . The general connexion of the subgroups will be best seen from the following Table:am a l , , am , f 50 d aml , am0 1 alt am2 , &c. faqo am al.2 , &c. 1 , A aq1 a ml 2 , &c. aq2 , &c. The same system is applicable to each division , 1 , 2 , and 3 , and to each group A , B , and C. We can easily express the subgroups by using one or more of the signs aq , am , al , am , with a figure to indicate the number of bands in the first term that contains any ; those before it being given to show the facts more clearly . Each colour can be indicated by writing after the subgroup the characteristic spectrum , or , for the sake of simplicity , merely the position of the centres of the bands , when they are seen as independent as possible ot general absorption . If the centres of the bands are in different positions the colours cannot be the same ; but if they agree it does not necessarily follow that they are the same . It is probable , but must be further proved by the correspondence of other spectra . As examples I give a few wellmarked cases . Purple Pansy ... ... ... ... ... ... ... .1 , A , a am ( 4 ) . Crimson Rose ... ... ... ... ... ... ... .1 , A , aq am a am ( 2 ) . Blue Lobelia ( L. speciosa ) ... ... ... ... 1 , B , aq ( 2:3 , 44 ) . Pink Stock ( Matthiola annua ) ... ... . 1 , B , aq ( 3- , 54 ) Several blue species of Campanula ... ... 1 , B , aq4 ( 28 , 4 , 5 % , 7 ) . Brazil-wood ( Caesalpinia crista ) ... ... ..1 , C , aq , ( 54 ) . Logwood ( Hcematoxylum campechianum ) 1 , C , aq , ( 48 ) . Sandalwood ( Pterocarpus santalinus)..3 , C , aq2 ( 6 , 7D ) . Alkanet-root ( Anchusa tinctoria ) ... ... 3 , C , aq3 ( 44 , 543 , 74 ) . 21 . Individual Colours . Having then ascertained to which subgroup any particular colour belongs , it is in the next place requisite to determine what particular substance it is . When it gives rise to well-marked absorption-bands , this may be more or less definitely decided by their exact position and character ; since they may of course occur in different situations , or vary much in absolute and relative breadth and in intensity . Thus , choosing closely related spectra , we have , for example,1 , B , aq2 , * Blue Lobelia speciosa ... ... ... . 24-34 ... 3-45 11 ... Pink Matthiola annua ... ... . . 23---44 ... 4---5 ... 8 10..111 , C , aql , Logwood ( Icematoxylum campechianum ) 3-5 *5 ... 7--8Brazil-wood ( Ccesalpinia crista ) - ... . 47-8 pi it ... 7--8 . 4 Such spectra are at once seen to differ most decidedly when compared side by side ; and that the colouring-matters are entirely different is proved by other facts . If the absorption-bands agree very closely , we ought to compare other spectra before concluding that the substances are the same . 22 . Mixed Colours . Of course , if any impurity is present which absorbs that part of the spectrum where the characteristic bands occur , it may be difficult , or even impossible , to determine the nature of the substance ; but the rest of the spectrum may be obscured , and the general colour entirely changed , without the least difficulty being thereby produced . Thus , for example , on adding a solution of Saffron ( Crocus sativus ) to that of the blue Lobelia , the colour is changed from blue to a curious olive , and the spectrum becomes* * Lobelia and Saffron ... ... ..3-4 6.7-Lobelia ... ... ... ... ... . 24-34 . 3--4 11 ... Difference ... ... ... ... ... ... ... ... . . 6..7-If we did not know it , we might thus infer that they were the same substance , and only differed because one contained a yellow colour ; and this conclusion would be borne out by adding to each citric acid and sulphite of soda , which make the Lobelia colourless , and leave the residual yellow colour , 6. . 7-- , in the case of the mixture . The petals of very many flowers do really contain more or less of such a yellow , which appears to be that developed to a much greater extent in the stamens , &c. ; and though this often modifies the general colour and the spectra , its presence may be recognized in a similar manner . Different species of Dianthus , various kinds of Roses , and Digitalis purpurea are good examples of one general colouring-matter modified in this manner . Its normal character is to have recourse to the position and character of the general absorption . This requires a good deal of care , since a difference in the state of the solution may make the same colour differ more than two quite distinct colours . After trying a number of experiments , I find that the best spectra for comparison are those obtained by adding first a moderate excess of carbonate of soda , and then a considerable excess of citric acid . Both of these solutions change very slowly , and give well-marked spectra ; whereas ammonia often causes decomposition , and weaker alkalies or acids give much more faint spectra , or such as rapidly fade . Closely related colours should be compared together , and made as nearly equal as possible after the addition of the carbonate , and then citric acid added in considerable , and nearly equal , excess . We thus can compare two different spectra ; and even if the position of the absorption is the same in both cases , the relative intensity may vary considerably . Very closely allied colours may often be easily distinguished in this manner , and the only great difficulty is when coloured impurities are present . As an example , I give some colours belonging to subgroup 1 , B , aqo amO alo am , . Carbonate of soda . Citric acid . Petals of Wallflower ( Chei } 215 8. . 9103..-7 ranthus Cheiri ) ... ... 4 Dark grapes ... ... ... . 2-1 ... .9 10..11-4..--..8~ Fruit of Elder ( Sam2 . -69 11 . bucus nigra ) ... ... . . 2 The first differs entirely from the latter two , but they are so similar that it requires great care to be sure that they differ essentially . If it were quite certain that such colours were pure , it would not be difficult to distinguish them with confidence ; but since they may contain coloured impurities , we must occasionally be content with results somewhat doubtful in questions of minute detail , which might not be of the least importance in some practical investigations . 24 . Yellow Colours . One of the best general methods of distinguishing yellow colours belonging to subgroup C , aqo , amo al am , or those with bands which are much alike , is to make them as nearly as possible of the same tint when neutral , and then to add excess of ammonia , which may make them very unequal . For exampleNeutral . Ammonia . Yellow Dahlia ( D. variabilis ) ... ... . . 8. . 9 --103 ... 4 -4 Yellow Calceolaria ( C. aurea-fioribunda ) 7 ... 9 116. . 6 -7Saffron ( Crocus sativus ) ... ... ... ... 7..8 -117. . 8 -11The action of ammonia thus shows that they differ very much , but at the same time the Calceolaria might be a mixture of the other two , and this would have to be decided by other facts . 25 . Fading of Group C. Sometimes in examining colours of group C , advantage may be taken of the different rate at which their acid solutions decompose and fade , when a considerable quantity of sulphite of soda has been added to an acid solution . The two solutions should be made as nearly equal as possible in all respects , and then the rate of fading may prove that they are very different , or may show that one is a mixture . After fading , the addition of excess of ammonia may show valuable facts . For example , the colour of the root of the red beet ( Beta vulgaris ) is pink , but that of the leaves is red , the spectrum differing from that of the root merely in having the blue end much absorbed . On keeping acid solutions of both to which sulphite of soda has been added , that of the root becomes colourless , and that of the leaves yellow ; and thus , considering that acid solutions of colours belonging to group C are very rarely pink , it is almost certain that the colour of the leaves is the same as that of the root , but modified by the yellow colour so common in leaves . 26 . Conclusion . Such , then , is a general outline of the method which I have hitherto found the most convenient in studying different colouring-matters , and for determining to what individual species any particular colour may belong . I need hardly say that it is just the sort of qualitative analysis to employ in detecting adulterations in many substances met with in commerce , as well as in inquiries where very small quantities of material are at command . By this method we might be able in a few minutes to form a very satisfactory opinion , or at least one that might meet all practical requirements , and even under unfavourable circumstances we might narrow the inquiry to a surprising extent ; and if this can be said even now , surely further research cannot fail to make it most useful in cases where ordinary chemical analysis would be of little or no use .
112672
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Optics of Photography.--On a Self-Acting Focus-Equalizer, or the Means of Producing the Differential Movement of the Two Lenses of a Photographic Optical Combination, Which Is Capable, during the Exposure, of Bringing Consecutively all the Planes of a Solid Figure into Focus, without Altering the Size of the Various Images Superposed
455
459
1,866
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Proceedings of the Royal Society of London
A. Claudet
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0102
null
proceedings
1,860
1,850
1,800
4
39
1,901
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112672
10.1098/rspl.1866.0102
http://www.jstor.org/stable/112672
null
null
Optics
47.302386
Measurement
32.027739
Optics
[ 21.96015167236328, -10.792128562927246 ]
I. " Optics of Photography.-On a Self-acting Focus-Equalizer , or the means of producing the Differential Movement of the two Lenses of a Photographic Optical Combination , which is capable , during the exposure , of bringing consecutively all the Planes of a Solid Figure into Focus , without altering the size of the various images superposed . " By A. CLAUDET , F.R.S. Received April 8 , 1867 . When a solid figure is brought too near the object-glass of a camera obscura , the difference of focus for its various planes is comparatively so great , that it is impossible that all the images should be equally well defined . Hence , in the case of photographic portraiture , there is a want of harmony in the representation of the various parts ; some are too sharply delineated , and some others are confused in proportion as they are more and more distant from the plane in focus . But there is another defect which is the consequence of the difference of distance of the various planes bearing too great a proportion to the distance of the whole , which is that the nearest parts of the figure are too much enlarged , and the furthest too much reduced . In a paper I read at the British Association at Nottingham in 1866 , I proposed a plan to obviate these defects , which consisted in bringing all the planes consecutively into focus , by moving , during the exposure , the tube of the lens or the back frame of the camera ; the consequence of which was , of course , that the planes were also during that movement brought out of focus ; so that a sharp image of every plane was impressed upon a confused image ; but they were all in the same degree in that mixed state , and the result was an equality of effect producing harmony in the whole , and that kind of softness in the picture so much approved by artists , as resembling , more than the sharpest photographs , the effect that they aim at producing . The original simple idea of equalizing the focus of the various planes by moving either the frame holding the plate , or the tube of the lens , during the exposure had , it appears , occurred to several persons engaged in photographic pursuits ( of which I was not aware before reading my paper ) ; but it is certain that the plan had never been practically and generally adopted , and that , at all events , no specimens of the process had at any time been exhibited in public , probably because it presented several difficulties which could not be easily overcome . The greatest of these difficulties I soon found during my investigations , which was that , in changing the focal distances merely by moving the frame or the tube , the size of the various superposed images was unavoidably reduced or increased according to the alteration of focus during the movement applied . Therefore I turned my attention to the means which might be found capable of avoiding this defect , and a fortunate idea presented itself , by which I found that it was possible to preserve the size of the various images during the adaptation of the focus to the different planes of the figure . The desideratum was , when changing the focus , to increase the power of the double lens for the planes the most distant and to reduce it for the nearest planes . At first this seemed to be an impossibility . But in considering the subject attentively , I was suddenly struck with the fact that the power of any double combination of . lenses being proportionate to the distance which separates the two lenses greater when they are more separated , and smaller when they are less separated , it was possible to alter the power of the combination by changing the distance between the two lenses . Therefore , if , instead of moving the whole tube containing the two lenses , we move only the back lens nearer the plate , when we want to focus for more distant planes , we increase at the same time the power of the double combination , and consequently the size of the image ; and if we move the lens further from the plate , when we want to focus for the nearest planes , in doing so , by reducing the separation of the two lenses , we reduce the power of the combination , and consequently also the size of the image . This is a most fortunate property ; for by this means it is possible not only to equalise the definition of the various planes , but at the same time to equalise the size of their images , and consequently to avoid the exaggeration of perspective by which the nearest planes are increased , and the furthest disproportionately reduced , a defect which is so detrimental to the apS pearance of large photographs . I submitted my plan to M. Voigtlander , the celebrated optician , and I had the satisfaction to meet with his entire approbation . He found that I had solved the problem in a way which was perfectly correct and sufficient in practice . But wishing to investigate the question from a higher mathematical point of view , and being unable from indisposition to go himself into the subject , he charged his step son , Dr. Sommer Professor of Mathematics at the Garolinian College of Brunswick , well versed in all the 2Q questions of optical photography , to calculate the result of the gradual increase and reduction of the power of the double combination , in conjunction with the alteration of focus . Dr. Sommer entered thoroughly into the subject , and soon sent me a series of elaborate formulae , showing that , although for all practical purposes in photography the movement of one of the two lenses , as I had proposed , fulfilled the object I had in view , still he found that a more scientific consideration of the subject called for a modification in my plan ; which was that , instead of moving only one of the lenses , the same degree of their separation should be imparted by moving the two lenses in contrary directions from the fixed centre of the combination , and in different proportions , according to the distance of the object . These differential proportions were indicated in a table calculated by Dr. Sommer which he sent me . This presented another difficult and unexpected problem , the solution of which was indeed most perplexing . But I did not like that it should be said that my plan was not completely in accordance with the mathematical laws of optics ; and I set to work at finding a mechanical means by which I could avail myself of the scientific calculations of Dr. Sommer . I have found such means ; and it turns out indeed that by my mechanical construction the differential movement can be effected , not only as readily and easily , but with a greater command and steadiness than by moving only one lens . The following is a description of the arrangement : Description of the Focus-Equalizer . The tube , containing at each end the lenses A and B , is divided into two parts , sliding in the principal tube SSSS fixed in the front of the camera at V V ' . Each tube has a strong pin , L and L ' . These two pins are intended to push the tubes to and fro from the centre of the combination on the line P P ' by means of the mechanical piece N N'N " in the shape of a sextant , having two slits , MM and M ' M ' , cut at an angle of 36 ? . Now the sextant , being mounted on a sliding bar q q ' , fixed in a socket holding to the tube SS SS at P P ' , can be made to move to and fro on the line P P ' by means of a rack and pillion moved by a handle V on the axis R. While the sextant moves in the line P P ' , the two slits will act on the two pins , and gradually increase the separation of the tubes ; and on making the sextant move back from P ' to P , the slits will bring the two pins nearer each other , and decrease the separation of the tubes . It will thus be easily understood how we can increase and reduce the separation of the two lenses from the centre of the combination ; but we have now to explain how we can produce the differential movement according to the mathematical formulae calculated by Dr. Sommer . The arc of the sextant is divided into 100 parts , in two rows one against the other . The divisions on the outer limb have their zero on the left , and the 100 division on the right ; on the inside limb the divisions are in a contrary direction . By means of the endless screw X acting on the toothed edge of the sextant , it can be moved on its horizontal axis , so that any of its divisions may be brought under the index fixed on the middle bar q q ' . Now , supposing that by the table of Dr. Sommer the lens A for a certain distance of the object should move 0'235 , and the lens B 01765 of the whole space by which the lenses require to be separated or approximated , we turn the endless screw until the index is on the 231 division of the inside scale , and of course on the 76 ? division of the outside scale . In that position of the sextant the slits MM and M ' M ' , by means of the pins attached to the tubes of the lens A and of the lens B , will make them accordingly move-A in the proportion of 0*235 , and B in the proportion of 0*765 of the whole space . If for another distance the lens A should have to move 0'333 , and the lens B 0*666 , setting both limbs of the sextant to these divisions , the lens A will move 5 , and the lens B3 of the whole space . If we wanted to move the two lenses in the same proportion , the sextant should be set so that the 50th division of both scales should be under the index . And , finally , if , for the sake of comparative experiments , it were wanted to move only the lens A or the lens B , the slit of the pin for either and the zero of the scale should be placed under the index , by which that lens would be completely stationary , and the whole motion imparted to the other . 459
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On the Genera Heterophyllia, Battersbyia, Palaeocyclus, and Asterosmilia; the Anatomy of Their Species, and Their Position in the Classification of the Sclerodermic Zoantharia. [Abstract]
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Proceedings of the Royal Society of London
P. M. Duncan
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
1
18
338
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112673
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http://www.jstor.org/stable/112673
null
null
Paleontology
73.545058
Biography
22.925168
Paleontology
[ -42.888816833496094, 26.61748695373535 ]
II . " 0On the Genera Heterophyllia , Battersbyia , Palkeocyclus , and Asterosmilia ; the Anatomy of their Species , and their Position in the classification of the Sclerodermic Zoantharia . " By Dr. P. M. DUNCAN , Sec. G.S. Communicated by Prof. HUXLEY . Received March 30 , 1867 . ( Abstract ) . Although the practical and natural classification of the Madreporaria ( Sclerodermic Zoantharia ) which has been submitted by MM . MilneEdwards and Jules Haime is very generally admitted to be the best , still there are great gaps in the succession of the genera , and , moreover , some genera cannot be placed . The " ' break " between the Turbinolides and the Astraeides is so great as to render the classification rather artificial ; but Dr. Duncan 's discovery of a genus Asterosmilia , comprising several species , unites these great divisions . The new genus has the peculiarities of the Trochocyathi , but in addition it is furnished with an endotheca . The species are described . The genera HeteropJhyllia , McCoy , and Battersbyia , Milne-Edwards and Jules Haime , are amongst those incertce sedis . The discovery of several new species of Heterophyllia enables Dr. Duncan to determine the anatomy of the genus , to offer for consideration the most extraordinary coral form he has ever seen , and to ally the genus with Battersbyia , which he proves had no coenenchyma . The species of both of the genera are described shortly , and the development and reproduction of B. gemmans also . The genera are placed amongst the Astraeidse . The genus Palceocyclus , M.-E . & J. H. , supposed to be one of the Fungidme , is proved to be a vesiculo-tuibulate coral genus , and to be one of the CyathophyllidEe . One Mesozoic family is therefore removed from the Palwozoic coral-fauna , and two genera of a Mesozoic division are introduced . They foreshadow the Thecosmilise of the Trias .
112674
3701662
Contribution to the Anatomy of Hatteria (Rhynchocephalus, Owen). [Abstract]
460
462
1,866
15
Proceedings of the Royal Society of London
Albert G\#xFC;nther
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
3
53
743
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112674
null
http://www.jstor.org/stable/112674
null
108,983
Anatomy 2
50.892149
Anatomy 1
26.227324
Anatomy
[ -66.33959197998047, 40.59779357910156 ]
III . " Contribution to the Anatomy of Hatteria ( Rhynchocephalus , Owen ) . " By ALBERT GiUNTHER , M.A. , Ph. D. , M.D. Communicated by Prof. OWEN . Received April 4 , 1867 . ( Abstract . ) The skull of Hatteria is distinguished by the following characters : 1 . Persistence of the sutures , especially of those between the lateral nalves of the skull , combined with great development of its ossified parts , as it appears in the expanse of the bones forming the upper surface of the facial portion , in the completeness of an orbital ring with a temporal and zygomatic bar ( Crocodilia ) , in the much expanded columella , in the nearly completely osseous bottom of the orbit , and roof of the palate . 2 . Sutural union of the tympanic with the skull ; firm and solid union of the bones of the palate with the tympanic , as shown by the sutural connexion of tympanic and pterygoid , broad sutural connexion of the columella with tympanic and pterygoid , immovable pterygo-sphenoid joint , firm and extensive attachment of pterygoid to ectopterygoid . 3 . This restriction of the mobility of the bones named is compensated by an increased and modified mobility of the lower jaw , the mandibles being united by ligament , and provided with a much elongate articular surface . 4 . Displacement of the palatine bones , which are separated by the pterygoids , and replace a palatal portion of the maxillaries . 5 . Perforation of the tympanic ; extremely short postarticular process of the mandible . The vertebral column and the remainder of the skeleton show the following peculiarities:1 . Vertebrae amphiccelian ; caudal vertebrse vertically divided into two equal halves . Points of minor importance are the uniform development of strong neural spines , and the direction of the caudal pleurapophyses which point forwards . 2 . The costal hsemapophyses are modified , first , into a series of appendages identical in position with the uncinate processes of birds ; and secondly , into a double terminal series connecting the ribs with the thoracic and abdominal sterna , the distal pieces being much dilated and forming the base of a system of muscles ( retractors of the abdominal ribs ) . 3 . The development of a system of abdominal ribs , standing in intimate and functional relation to the ventral integuments . 4 . Continuity of the ossification of the coracoid ; presence of an acromial tuberosity of the scapula ; subvertical direction of the os ilium . 5 . The arrangement of the bones of the limbs and their muscles does not show any deviation from the Lacertian type . The dentition of Hatteria is unique . That of young examples differs scarcely from the dentition of other acrodont lizards . In adult examples the intermaxillaries are armed with a pair of large cutting-teeth ; a part of the lateral teeth are lost , and the alveolar edges of the jaws are cutting and highly polished , performing the function of teeth . A series of palatine teeth is in close proximity and parallel to the maxillary series , both series receiving between them in a groove the similarly serrated edge of the mandible . As regards the organs of sense , the absence of the pecten of the eye and of the tympanic cavity , the commencement of a spiral turn of the cochlea , and the attachment of the hyoid bone to the terminal cartilage of the stapes-are to be noticed . The structure of the heart and of the organs of respiration and circulation are of the Lacertian type . The absence of a copulatory organ is a character by which Hatteria is Prof. Cayley on the Curves distinguished from all other Saurians . Thus Hatteria presents a strange combination of elements of high and low organization , and must be regarded as the type of a distinct group . Its affinities and systematic position may be indicated in the following synopsis of RECENT REPTILIA : I. SQUAMATA . First order . Ophidia . Second order . Lacertilia . Suborder A. Amphisbcenoidea . Suborder B. Cionocrania . Suborder C. Chameeleonoidea . Suborder D. Nyctisaura . Third order . Rhynchocephalia . II . LORICATA . Fourth order . Crocodilia . III . CATAPHRACTA . Fifth order . Chelonia .
112675
3701662
On the Curves Which Satisfy Given Conditions. [Abstract]
462
462
1,866
15
Proceedings of the Royal Society of London
Prof. Cayley
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
1
8
254
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112675
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http://www.jstor.org/stable/112675
null
108,908
Formulae
75.870522
Biography
21.799231
Mathematics
[ 62.85096740722656, -32.885833740234375 ]
IV . " On the Curves which satisfy given conditions . " By Prof. CAYLEY , F.R.S. Received April 18 , 1867 , ( Abstract . ) The present memoir relates to portions only of the subject of the curves which satisfy given conditions ; but any other title would be too narrow : the question chiefly considered is that of finding the number of the curves which satisfy given conditions ; the curves are either curves of a determinate order r ( and in this case the conditions chiefly considered are conditions of contact with a given curve ) , or else the curves are conics ; and here ( although the conditions chiefly considered are conditions of contact with a given curve or curves ) it is necessary to consider more than in the former case the theory of conditions of any kind whatever . As regards the theory of conics , the memoir is based upon the researches of Chasles and Zeuthen , as regards that of the curves of the order r , upon the researches of De Jonquieres : the notion of the quasi-geometrical representation of conditions by means of loci in hyper-space is employed by Salmon in his researches relating to the quadric surfaces which satisfy given conditions . The papers containing the researches referred to are included in a list subjoined . I reserve for a separate second memoir the application to the present question , of the Principle of Correspondence . 462 [ May 2 ,
112676
3701662
Second Memoir on the Curves Which Satisfy Given Conditions; the Principle of Correspondence. [Abstract]
463
463
1,866
15
Proceedings of the Royal Society of London
Professor Cayley
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
1
9
473
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112676
null
http://www.jstor.org/stable/112676
null
null
Formulae
89.421852
Biography
8.648634
Mathematics
[ 62.71443176269531, -33.058353424072266 ]
V. " Second Memoir on the Curves which satisfy given conditions ; the Principle of Correspondence . " By Professor CAYLEY , F.R.S. Received April 18 , 1867 . ( Abstract . ) In the present memoir I reproduce with additional developments the theory established in my paper " On the Correspondence of two points on a Curve " ( London Math. Society , No. VII . , April 1866 ) ; and I endeavour to apply it to the determination of the number of the conics which satisfy given conditions ; these are conditions of contact with a given curve , or they may include arbitrary conditions Z , 2Z , &c. If , for a moment , we consider the more general question where the Principle is to be applied to finding the number of the curves Cr of the order r , which satisfy given conditions of contact with a given curve , there are here two kinds of special solutions ; viz. , we may have proper curves C ' touching ( specially ) the given curve at a cusp or cusps thereof , and we may have improper curves , that is , curves which break up into two or more curves of inferior orders . In the case where the curves C ' are lines , there is only the first kind of special solution , where the sought for lines touch at a cusp or cusps . But in the case to which the memoir chiefly relates , where the curves C " are conics , we have the two kinds of special solutions , viz. , proper conics touching at a cusp or cusps , and conics which are linepairs or point-pairs . In the application of the Principle to determining the number of the conics which satisfy any given conditions , I introduce into the equation a term called the " Supplement " ( denoted by the abbreviation " Supp. " ) , to include the special solutions of both kinds . The expression of the Supplement should in every case be furnished by the theory ; and this being known , we should then have an equation leading to the number of the conics which properly satisfy the prescribed conditions ; but in thus finding the expression of the Supplements , there are difficulties which I am unable to overcome ; and I have contented myself with the reverse course , viz. , knowing in each case the number of the proper solutions , I use these results to determine a posteriori in each case the expression of the Supplement ; the expression so obtained can in some cases be accounted for readily enough , and the knowledge of the whole series of them will be a convenient basis for ulterior investigations .
112677
3701662
On the Development and Succession of the Teeth in the Marsupialia. [Abstract]
463
468
1,866
15
Proceedings of the Royal Society of London
William Hanry Flower
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
5
67
2,331
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112677
null
http://www.jstor.org/stable/112677
null
108,984
Anatomy 2
58.284014
Biology 1
18.134675
Anatomy
[ -67.81495666503906, 52.4168815612793 ]
I. " On the Development and Succession of the Teeth in the Marsupialia . " By WILLIAM HENRY FLOWER , F.R.S. , F.R.C.S. , &c. , Conservator of the Museum of the Royal College of Surgeons of England . ( Abstract . ) Although the dentition of adult individuals of all the animals which constitute the remarkable Order or , rather , Subclass Marsupialia , has been repeatedly subjected to examination , and described with exhaustive minuteness of detail , it is a singular circumstance that most of those peculiarities in the succession of their teeth which distinguish them from other mammals appear hitherto to have escaped observation . To supply this blank is the object of the present communication . Fortunately the materials at my disposal , although not quite so complete as might be desired , are yet amply sufficient to illustrate the main aspects of the question , and to supply a result as interesting as it was unexpected . Descriptions are given in the paper , accompanied by drawings , of several stages of the dentition of members of each of the six natural families into which the order is divided . 1 . Macropodidce.-The dentition of the Kangaroo ( genus Macropus ) , from the completely edentulous foetus to adult age , is described in detail . Contrary to what has been specially stated with regard to this genus , there are no deciduous or milk-incisors , the teeth of this group which are first formed and calcified in both jaws being those which are retained throughout the life of the animal . The rudimentary canine and first premolar have also no deciduous predecessors . The second tooth of the molar series ( a true molar in form ) is vertically displaced by a premolar . The four true molars have , as has long been known , no deciduous predecessors . There is thus but one tooth on each side of each jaw in which the phenomenon of diphyodont succession occurs . The period at which this takes place varies in different species of the family . In some forms of Hypsiprymnus , the successional premolar is not cut until after the last true molar is in place and use , -this probably having relation to the extraordinary size of the tooth , and the time consequently required for its development . A special characteristic of this family is the tendency to lose the canine and one or both premolars at a comparatively early period of life . 2 . Phalangistidce.-Several early stages of the dentition of Phalangista vulpina are described and figured . In a young specimen in which no teeth had cut the gum , the crowns of the permanent incisors , canine , and first two molars were found to be calcified , and the germ of the permanent premolar was already formed beneath the milkor deciduous molar , which , as in Macropus , is the only tooth which is shed and replaced by a successor . The change takes place at an earlier period than in the last family . 3 . Peramelidce.-No very early stages of Perameles were examined ; but adolescent specimens of this genus and of Chceropus show that a very minute , compressed , molariform tooth is replaced by the triangular , pointed , third or posterior premolar . No other signs of vertical displacement and succession were observed . 4 . Didelphide . In the American genus Didelphys , the observations are complete from the earliest stage , and show that , as in the Australian Macropodidce and Phalanyistidce , none of the teeth of the permanent series have predecessors except the compressed pointed last premolar , which replaces a tooth having the broad multicuspidate crown of a true molar . This change does not occur until the animal apiproaches the adult age . 5 . Dasyuridte . In a fetal Thylacinus , in which no teeth had cut the gum , the crowns of the permanent incisors , canines , premolars , and anterior true molars were partially calcified , and necessarily much crowded together in the jaw . A very minute rudimentary molar was situated just beneath the alveolar mucous membrane , superficially to the apex of the hindermost premolar , and was evidently its milk-predecessor . 6 . Phascolomyid & e.-This family is placed last because the observations regarding it are less complete than in the case of any of the others . The youngest Wombat available presented no evidence of succession of any of the teeth ; but it is probable that the single premolar is preceded by a milk-molar , at a still earlier period than any examined . From the foregoing observations it may be concluded with tolerable safety that the animals of the Order Marsupialia present a peculiar condition of dental succession , uniform throughout the order , and distinct from that of all other mammals . This peculiarity may be thus briefly expressed . The teeth of Marsupials do not vertically displace and succeed other teeth , with the exception of a single tooth on each side of each jaw . The tooth in which a vertical succession takes place is always the corresponding or homologous tooth , being the hindermost of the premolar series* , which is preceded by a tooth having the characters , more or less strongly expressed , of a true molar . It has been usual to divide the class Maammalia , in regard to the mode of formation and succession of their teeth , into two groups the Monophyodonts , or those that generate a single set of teeth , and the Diphyodonts , or those that generate two sets of teeth ; but even in the most typical diphyodonts the successional process does not extend to the whole of the teeth , always stopping short of those situated most posteriorly in each series . The Marsupials occupy an intermediate position , presenting as it were a rudimentary diphyodont condition , the successional process being confined to a single tooth on each side of each jaw . This position , however , is by no means without analogy among the mammals of the placental series . In the Dugong and the existing Elephants the successional process is limited to the incisor teeth . It is questionable whether the first premolar of those animals of this group which have four premolar teeth , as the Hog , Dog ( mandible ) , &c. , ever has a deciduous predecessor , at all events so far advanced as to have reached the calcified stage . But the closest analogy with the marsupial mode of succession is found among the Rodents . Here the incisors appear to have no deciduous predecessors ; and in the Beaver , Porcupine , and others , which have but four teeth of the molar series , i. e. three true molars and one premolar , the latter is , exactly as in the Marsupials , the only tooth which succeeds a deciduous tooth . The analogy , however , does not hold in those Rodents which have more than one premolar , as the Hare ; for in this case each of these teeth has its deciduous predecessor . In the preceding account I have used the term " permanent " for those teeth which remain in use throughout the animal 's life , or , if they fall out ( as do the rudimentary canines and the premolars of the Macropodidce ) , do not give place to successional teeth ; and I have therefore assumed that the milk or temporary dentition of the typical diphyodont mammals is represented in the Marsupials only by the deciduous molars . It may be held , on the other hand , that the large majority of the teeth of the Marsupials are the homologues of the milk or first teeth of the diphyodonts , and that it is the permanent or second dentition which is so feebly represented by the four successional premolars . This view is supported by many general analogies in animal organization and development , such as the fact that the permanent state of organs of lower animals often represents the immature or transitional condition of the same parts in beings of higher organization . Looking only to the period of development of the different teeth in some of the marsupial genera , we might certainly be disposed to place the successional premolar in a series by itself , although , indeed , all its morphological characters point out its congruity with the row of teeth among which it ultimately takes its place , the reverse being the case with its predecessor . It is , however , almost impossible , after examining the teeth of the young Thylacine described and figured in the paper , to resist the conclusion originally suggested . The unbroken series of incisors , canines , premolars , and anterior true molars of nearly the same phase of development , with posterior molars gradually added as age advances , form a striking contrast to the temporary molar , so rudimental in size , and transient in duration . I can scarcely doubt that the true molars of this animal would be identified by every one as homologous with the true molars of the diphyodonts , which are generally regarded as belonging to the permanent series , although they never have deciduous predecessors . Now , if the homology between the true molars of the Thylacine and those of a Dog , for instance , be granted , and if the anterior teeth ( incisors , canines , and premolars ) of the Thylacine be of the same series as its own true molars , they must also be homologous with the corresponding permanent teeth of the Dog . It may be objected to this argument , that the true molars of the diphyodonts , not being successional teeth , ought to be regarded as members of the first or milkseries ; but , in truth , the fact that they have themselves no predecessors does not make them serially homologous with the predecessors of the other teeth , while their morphological characters , as well as their habitual persistence throughout life , range them with the second or permanent series . We have been so long accustomed to look upon the second set of teeth as an after-development or derivative from the first , that it appears almost paradoxical to suggest that the milkor deciduous teeth may rather be a set superadded to supply the temporary needs of mammals of more complex dental organization . But it should be remembered that , instead of there being any such relation between the permanent and the milk-teeth as that expressed by the terms " progeny " and " parent " ( sometimes applied to them ) , they are both ( if all recent researches into their earlier development can be trusted ) formed side by side from independent portions of the primitive dental groove , and may rather be compared to twin brothers , one of which , destined for early functional activity , proceeds rapidly in its development , while the other makes little progress until the time approaches when it is called upon to take the place of its more precocious locum tenens . Many facts appear to point to the milk-teeth as being the less constant and important of the two sets developed in diphyodont dentition . Among these the most striking is the frequent occurrence of this set in a rudimentary and functionless or , as it were , partially developed state . The milkpremolars of some Rodents ( as the Guinea-pig ) , shed while the animal is in utero , the simple structure and evanescent nature of the milk-teeth of the Bats , Insectivores , and Seals , the diminutive first incisors of the Dugongs and Elephants , all appear to be cases in point . On the other hand , examples of the commencing or sketching out , as it were , of the successors to a well-formed , regular , and functional first set of teeth , are rarely , if ever , met with . Occasional instances of the habitual early decadence , or , perhaps , absence of some of the second or so-called permanent teeth occur in certain animals ; but these are rather examples of the disappearance or suppression of organs of which there is no need in the economy , and chiefly occur in isolated and highly modified members of groups in the other members of which the same phenomenon does not occur , as in Cheiromys among the Lemurs , Trichechus among the Seals , and the recent Elephants ( as regards the premolars ) among the Proboscideans . They form no parallel to the cases mentioned above of the rudimentary formation of an entire series of teeth of the temporary or milk-set . To return to the marsupials:-If this view be correct , I should be quite prepared to find , in phases of development earlier than those yet examined , some traces either of the papillary , follicular , or saccular stages of milkpredecessors to other of the teeth besides those determinate four in which , for some reason at present unexplained , they arrive at a more mature growth* . Such proof as this would alone decide the truth of these specu* It may be remarked that the milk-tooth , which alone is developed in the Marsu lations ; and I have not at present either the requisite leisure or materials for following out so delicate an investigation . I trust that the facts already elicited are sufficiently novel and important to justify my bringing them , as they now stand , before the Society .
112678
3701662
On a Property of Curves Which Fulfil the Condition d\lt;sup\gt;2\lt;/sup\gt;\#x3C6;/dx\lt;sup\gt;2\lt;/sup\gt; + d\lt;sup\gt;2\lt;/sup\gt;\#x3C6;/dy\lt;sup\gt;2\lt;/sup\gt;=0
468
469
1,866
15
Proceedings of the Royal Society of London
W. J. Macquorn Rankine
fla
6.0.4
null
null
proceedings
1,860
1,850
1,800
2
28
721
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112678
null
http://www.jstor.org/stable/112678
null
null
Formulae
71.545523
Fluid Dynamics
12.037218
Mathematics
[ 65.88703918457031, -30.02019691467285 ]
II . " On a Property of Curves which fillfil the condition d2 + 0 . " By W. J. MACQUORN RANKINE , C.E. , LL. D. , F.R.SS . L. & E. Received April 9 , 1867 . 1 . In a paper " On Stream-Lines , " published in the Philosophical Magazine for October 1864 , I stated , and , in a Supplement to the same paper , published in the Philosophical Magazine for January 1865 , I proved the proposition that " all waves in which molecular rotation is null begin to break when the two slopes of the crest meet at right angles . " 2 . I have now to state the purely geometrical proposition of which that mechanical proposition is a consequence . If a plane curve which fulfils the condition d+ =0 cuts itself in a double point , it does so at dx2 dy2 rizht angles . 3 . The following is the demonstration . It is well known that the inclination of any plane curve to the axes at an ordinary point is given by the equation d dx +d dy=0 ; dx die also that at a double point §§ and d both vanish , so that the inclinations dx die of the two branches to the axes are given by the two roots of the quadratic equation d. d2 +2 da . dx die + Jr dy2 = ; dx2 dx die die whence it follows that the product of the two values of die , which are the d2 two values of the tangent of the inclination to the axis of x , is = dx . In d2 dy2 a curve which fulfils the before-mentioned condition , the value of that product is -1 ; and when such is the case with the product of the tangents of two angles , the difference of those angles is a right angle ; therefore the two branches cut each other at right angles . Q.E.D. 4 . The proposition just demonstrated is so simple and so obvious , that pials , corresponds homologically with that which , as a general rule , is most persistent in ; the typical diphyodonts , including Man , viz. the posterior milk-molar , replaced by the posterior permanent premolar . I was at first disposed to think it must have been known and published previously ; and had I not been assured by several eminent mathematicians that it had not been previously published to their knowledge , I should not have ventured to put it forth as new . Supplement to the preceding Paper . Received April 23 , 1867 . Professor Stokes , D.C.L. , has pointed out to me an extension of the preceding theorem , viz. that at every multiple point in a plane curve which fulfils the condition d2 ' + d=0 , the branches make equal angles with dx2 die ' each other ; so that , for example , if n branches cut each other at a multiple point , they make with each other 2n equal angles of - . n The following appears to me to be the simplest demonstration of the extended theorem . At a point where n branches cut each other the following equation is fulfilled by all curves : ( dx + die ) 9O . Let 0 be the angle made by any branch with the axis of x ; then cos 0 d-+ sin 0d = O. ( dx die But in a curve which fulfils the equation d2+ d =0 , we have dx2 dy ' d , _l d die dx whence it follows that in such a curve the equation of a multiple point of n branches is { ( cos 0+ - . sin 0 ) =0 . Choose for the axis of xa tangent to one of the branches at the multiple point . Then it is evident that the preceding equation is satisfied by the 2n values of 0 corresponding to the 2nth roots of unity , that is to say , by =0 , 7r 27r &c. , ( 2n1)7 . 0= 0 , *nnn therefore the n branches make with each other 2n equal angles of - . Q.E.D. n 469
112679
3701662
A Tabular Form of Analysis, to Aid in Tracing the Possible Influence of past and Present upon Future States of Weather
470
474
1,866
15
Proceedings of the Royal Society of London
S. Elliott Hoskins
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0109
null
proceedings
1,860
1,850
1,800
5
120
2,628
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10.1098/rspl.1866.0109
http://www.jstor.org/stable/112679
null
null
Meteorology
44.913982
Agriculture
15.438879
Meteorology
[ 41.36651611328125, 21.152175903320312 ]
III . " A Tabular Form of Analysis , to aid in tracing the Possible IInfluence of Past and Present upon future states of Weather . " By S. ELLIOTT HOSKINS , F.R.S. , &c. Received March 28 , 1867 . The data upon which the present communication is founded are derived from the ' Greenlwich Reports , ' from Mr. Glaisher 's papers in the Philosophical Transactions , and from my own observations at Guernsey . The latter were commenced in the autumn of 1842 , in accordance with the recommendations of the Committee of Physics of the Royal Society , and were taken at the request of Professor Daniell , by whom the irnstruments employed were selected . These instruments , made by Newman , were after a time replaced by others , at the suggestion of Mr. Glaisher , by whom they were compared with the standards at the Royal Observatory . For my own guidance in the first instance , I sought to arrange the results thus obtained in such a marnner as to discover , if possible , whether any month or class of moniths stood to each other in the relation of cause and effect ; in other words , whether the atmospheric conditions of autumn exercised any distinguishable influence upon the fruitful or unfruitful character of ensuing seasolns . In order to attain this object , the priilciple seemed to be that of condensing within narrow limits , by means of intelligible symbols , as many elements of weather , in the popular acceptance of the word , as might be required . But the ordinary curvilinear form of diagram could not be so modified as to answer this purpose , and I therefore availed myself of a plan suggested by Mr. Galton:-that of converting the records of observations into appropriate signs , and placing them compactly in a series of squares . Upon this principle the annexed diagrams* are constructed , comprising those elements of weather which more directly affect vegetation ; viz. heat , cold , dryness , moisture , and their combinations . The same kind of preparatory steps were taken for the compilation of the Greenwich as for the Guernsey diagram , so as to render the results comparable-less , perhaps , for the sake of mere comparison , than for the purpose of testing the value of the latter by means of an accredited standard . The first process consisted in copying out the degrees of monthly mean temperature , the number of rainy days , and the days of wind , from four directions , intermediate to the cardinal points . These several copies being verified , the monthly average of each of the above elements for twenty years , from 1843 to 1862 , was taken . The next step was to obtain the difference between the adopted average and the mean of each month in every year . By prefixing the plus and minus signs to the resulting figures , the excess and defect of each element is shown . The third process was to separate the above-mentiorned series of years into two decennial periods or decades , and then to compute , not only the number of months above and below the average , but also the degrees of temperature . ( See Tables I. , II . , III . , V. and VI . in the Appendix . ) Lastly , the numerals thence derived were converted into . simple and familiar signs , which were then delineated upon a sheet of sectional paper , accurately engraved according to scale . A square space was allotted to each of the months , and they were laid down as abscissas , with the years for ordinates . ( See Diagrams I. and II . ( Archives ) . ) The light squares in the diagramis deniote warmth , the degrees being expressed by a modification of the plus sign , in red inik ; the dark , or shaded squares indicate cold , and the degrees are marked in black ink with the minus sign . Black dots indicate the number of rainy days above the average , and red dots the number below it . The diagonlal linies from the centre of each square show the direction and days of predominant wind , one-sixteenth of an inch being equivalent , to five days beyond the mean ; the red lines are associated withi dryness , and the black with moisture . It may be necessary to explain that , as regards rainfall , frequency , rather than quantity , was selected as a criterion . That is to say , the number of days on which rain fell rather than the number of inches collected by the pluviometer ; for it not unfrequently happens that a few heavy showers yield a greater amount of wa.ter than many days of gentle rain of long , continuance . The combined signs in the above arralngement are intended to represent four different states of weather , viz. warm+dry ; warm+wet ; cold+dry ; and cold+wet . If the sectional paper be large enough to admit of blank spaces being left , the signs of the weather may be delineated therein as each mouth elapses ; and thus the diagram becomes a sort of register , and an ever-ready table of reference . For instance , by rulning the eye along the vertical columns of the Guernsey diagram , to which I must confine myself for the present , the existing state of the weather can easily be compared with that of corresponding months , up to 1843 ; and by following each horizontal line of squares the character of each year may as readily be ascertained . Thus we shall find , on comparing the September of 1865 with that of preceding years , that it was the hottest and the driest of the whole series . On looking along the ordiniate corresponding to 1846 , it will be seen that during , eleven months of that year the temperature was uniformly above the adopted average . On taking a general view of this diagram , after its completioni , a vervy cursory glance sufficed to show me that a striking differenice existed in the distribution of lig , ht and shade . On closer inspection , it became maniifest that the number of light squares in the one decade exactly couniterbalanced the dark squares in the other ; so that the warm months of the first period were in direct ratio to the coldI months of the second . These contrasts , quite unlooked for by me , were all the more surprising , as the data employed had been taken as they came , and not selected for the purpose of supporting any preconceived notion . It seemed to me , therefore , that this kind of diagram , besides serving as a convenient table of reference , was a collection of materials prepared and classified for further analysis . Under this impressiou I proceeded to decompose it , and to rearrange the products in a tabular form*-converting into letters of the alphabet the combine ed signs in the squares , so as to designate the foir states of weather , before mentionied , as follows:-A =war'a ' + dry ; B= warm + wet ; C= cold + dr , and D= cold + wet . These letters were them placed in columns under the heads of mnoniths and years ; the number of timtes in which each letter recurred was noted , and these numerals , which may be termed coeecients of the sums of the letters , were collected in linles and columns , those of the months at the foot , and those of -he years at the sides of a table of atiialsis . See Table IV . When the coefficients of the whole series were thus placed in . juxtaposition , it was satisfactory to find that the general contrasts , noticed in the diagram , were bornie out numerically ; and still more satisfactory to ascertain that there was a close agreemenit betweeni the ratio of the months and that of the degrees of temperature , plus and minus . Months . Degrees . First decade . 78 warm to 42 cold . 1530'5 pltus to 550 2 imiinUs . G er Second decacae . 78 cold to 42 warm . 1530.0 mntus to 000.0 plus . e nacy The columins at th e sides ol the Tables of anilysis , that of Greenwich as well as Guernsey , indicate that there was the it trtrsion of one cold year ( 1845 ) in the warm perioc , and of two warm years ( 1857 and 1859 ) ill the cold period . A similar kind of inltercalation was pointed out by Mr. Howard , in his I Cycle of the Seasons , ' from 1824 to 184 1 , i amely , the intrusioni of one cold year in the warm , and one warm year in the cold cycle . On examinint n the coefficients riore in detail , in the hope of being -able to detect some group of inoiiths which seemed to bear a peculiar relation to the rest , I met with a frequent recurrence of anx exact inverse order between the warm months of the two decades ; and oft a direct ratio between the wet and dry . Durung the first decade , the ratio between wart and cold , in the groups of January , February , March , April , August , Septemnber , October , and December , is invariably 6 to 4 . It is one of greater inequality in the Junes and Novehbers , being 8 to 2 in both cases ; warm MJays are equal to the cold , but warm Julys preponderate in the proportion of 9 to 1 . In the second decade , the rarm Novetlbers are to the cold the exact reverse of whiat tiev were in the first , being 2 to 8 ; and the ratios of Ja* I arn indebted to Dr. Gtuy 's Croonian Lectiires for n insiglt into this method . nuary , February , iarch , and April are also reversed , being 4 to 6 , instead of 6 to 4 . Wbhen onie decade is compared with the other , the last-named months are found to stand in exact inverse order , viz. 6 to 4 in the first , and 4 to 6 in the second . The wet and dry groups ceern , on the whole , to be more evenly balanced than the warm and cold ; but the Novernbers of the second decade are remarkable for dryn-ess . The connexion between the predominant winds and the other states of weather has not as yet been traced systemiatically but the diagram shows great excess of north-east wiid in thespring 01 18552 , and a loog conitin uanee of cold weather sCttiDg in early in the following year . It is also evident that wind from south-eastwas nor prevalent ( uining thie second thanthe first decade . Prom the foregoing comparisoni of the different months , the groulp of Novembers seems to be the most exceptional ; it may therefore be worth wshile to recapitulate the peculiarities that have been nioticed . Lsr . Th-e r'atio between the coefficients of this group in di ; erenit decades is invariably onie of con siderable inequality . 2nld . Two cold Novembers only occur in the warm cycle , and only two w1arm ones in the cold cycle . 3rd . In the second decade the proportion of warm to cold Novembers is 8 to 2 , and of dry and wet 2 to 8 ; but in the warm period warm and wet m11onths were prettily evenly distributed . 4tl . ioviembers of conmparatively low tenmperature , such for instance as those of 1851 , 1853 , 1854 , 1855 , 1856 , 1860 , 1861 , and 1862 , were in eaeb year succeeding those enumerated , followed by Ma is or Junes of a sirmilar character . The following rs me ' shows the relations between the Novembers and the Junes . M-onths . Nove , mbers . Jtnes . Gue r Isey . 1st decade . 8 warmii to 2 colcl . 8 warmrL to 2 cold . 9i 2n decade . 8 cold to 2 warim . 7 cold to 3 warm . DIegrees . Novembers . Jllmes . Iue st n esade 15{7 %plus to 40^2 minus . 17 ' ? 5 phlis to 3'-O m-tinus . luernsey- . 2nd deladl.e . 14 ? ` 0 mi-nus to 23-8 plus . 180 5 minus to 3 ? .1 plus . These contrasts and analogies seemi to ju1stify the surmise that the atmospheric conditions of the former monthis may have exercised some irifluence upon those of the latter . WAThether such be the case generally is not to be determinied until a miiuch longer series of results at Guernsey can be compared . The peculiarities withi respect to the Novembers may he purely accidental , or confined to the period under consideration ; but that they are 2 it jot restricted to locality is proved by the Greeniwich Tables , in which these groups staned out still more prominenitly ( see Table VII . ) ; the ratios between warm and cold being 9 to 1 in the first decade , and 1 to 9 in the second . It is difficult therefore to avoid the conclusion that , during the twenty years in question , the Nove-n-bers were exceptional months at both places ; although at Guernsey they were more frequently followed by unfavourable Junes . The Greenwich diagram ( Diagram II . Archives ) , to which I must now briefly advert , does not exhibit so strikin , a contrast of light and shade as was observable at first sight in the other diagram . B1ut on fri-ther examination it will be found that the warm months of the first decade correspond nearly in number with the cold months of the second , although not so exactly as at Guernsey . Months . Degrees . Greenwch . f Ist decade . 65 warnm to 55 cold . 157 ? -5 plus to 1080.5 imiinuis . Greenwil . * 2nd decade . 62 co]cl to 58 warm . 148 ? 4 minus to 11 6 ? 8 plus . Oni comparing the above abstract with that in a previouis page , it will be perceived that the disparity between the general results , from both places , is not very considerable ; a similarity all the more remarkable , whenl we consider the great difference in position and latitude of the inlland and the insular stations . See Diagram III . It would be superfluous to enter into any further discussion of the various alterniations which the coefficienlts are susceptible of , in a paper which is merely intended to direct attention to the accompanying diagrams and arnalytical tables . My motive for venturing to bring them under notice is a desire to place them in the hands of those better qualified than I am for conducting processes of iniduction ; and as the modified plan I have adopted is based upon long recog , nized principles , which are applicable to the investigation of atmospheric phenomena in any locality , I trust that it may be deemed worthy of consideration .
112680
3701662
Monthly Magnetic Determinations, from June to November 1866 Inclusive, Made at the Observatory at Coimbra
474
481
1,866
15
Proceedings of the Royal Society of London
J. A. De Souza
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0110
null
proceedings
1,860
1,850
1,800
2
22
560
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112680
10.1098/rspl.1866.0110
http://www.jstor.org/stable/112680
null
null
Meteorology
60.461533
Tables
14.087363
Meteorology
[ 48.98661422729492, 11.534582138061523 ]
IV . " ; Monthly Magnetic iDeterminiations , from June to November 1866 inclusive , made at the Observatory at Coimbra , " by Professor J. A. DE SOUZA , Director of the Observatory . Communicated ( with a Note ) by the President . RXeceived Alay 8 , 1867 . [ NOTE.-These observations contain the record of the commencemenit of the absolute mragnetic determinations at thie Coimbra Observatorv , with instruments procured by M. de Souza at Kew , and on the system of observation and reduction adopted at the Kew Observatory . The employment of the photographic continuously self-recording instruments at Coimbra has hitherto been delayed by the works requir:ed for the introduction of gas into the Observatory ; but this has now been accomplished ; and a letter , dated April 20 , 1867 , from the Director states that the plhotographic records were at that date on the point of commencing . The latitude and longitude of the Observatory are 40§ 12'-5 N. , and 80 25 ' W.E. S. ] 06servations of De/ fection , Vibration , and Dip taken at the Coimbraz Observatory , 1866 . The horizontal , vertical , and total forces are calculated to English measure . The vertical and total forces are obtained from the absolute measures of horizontal force and dip . The value of log 7r2 K determined at the Kew Observatory is= 1 64829 at temp. 620 Fahr. The value of log , is =6 30487 . The values of the coefficients q and q ' are respectively 0 000128 , 0 00000030 . The temperature correction was obtained from the formula q(to-38 ) + q ' ( to38)2 . The correction for error of graduation of the deflectioni-bar at 1'0 foot is = -0o00006 , at 13 is =-0'00024 . The time of one vibration has been obtainied from the mean of twenty-four determinations of the time of 100 vibrationis . The angles of deflection are each the mean of two determinations . The difference between the angles of every pair was found always less than 40 " . In deducing from these observations the ratio and product of the magnetic moment m of the magnet , and of the earth 's horizontal magnetic intenisity X , no correction has been required for the rate of the chronometer , or for the initial and terminal semiarcs of vibration , the former having been always less than 2'50 , and the latter less than 70 ' at commencement , and 30 ' at end . But the induction and temperature corrections have always been applied , and the observed time of vibration has been corrected for the effect of torsion of the suspending thread . The torsion for 900 was found no less than 5'*18 , and no greater than 8 ' 67 . In the calculations of the ratio X the third and subsequent terms of the series 1 +.2+ R+ &c. ve been omitted . The valuie of the constant P was fouiid to be = -0 ) 0022317 , by the meani of thirty-one determinations obtained each frozm two pairs of deflection observa.tions at distanices 10 and 13 foot . The horizontal force for each day is the mean of those calculated for each pair of deflections at distances 1P0 and 13 foot .
112681
3701662
On the Internal Distribution of Matter Which Shall Produce a Given Potential at the Surface of a Gravitating Mass
482
486
1,866
15
Proceedings of the Royal Society of London
G. G. Stokes
fla
6.0.4
http://dx.doi.org/10.1098/rspl.1866.0111
null
proceedings
1,860
1,850
1,800
5
51
2,355
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112681
10.1098/rspl.1866.0111
http://www.jstor.org/stable/112681
null
null
Fluid Dynamics
66.465617
Formulae
31.045688
Fluid Dynamics
[ 48.310489654541016, -24.468355178833008 ]
I. " On the Internal Distribution of Matter which shall produce a given Potential at the Surface of a Gravitating Mass . " By G. G. STOKES , M.A. , Sec. R.S. , Lucasian Professor of Mathematics in the University of Cambridge . Received April 18 , 1867 . It is known that if either the potential of the attraction of a mass attracting according to the law of the inverse square of the distance , or the normal component of the attraction , be given all over the surface of the mass , or any surface enclosing it ( which latter case may be included in the former by regarding the internal density as null between the assumed enclosing surface and the actual surface ) , the potential and consequently the attraction at all points external to the surface and at the surface itself is determinate . This proposition leads to results of particular interest when applied to the Earth , as I showed in two papers published in 1849* , where among other things I proved that if the surface be assumed to be , in accordance with observation , of the form of an ellipsoid of revolution , Clairaut 's Theorem follows independently of the adoption of the hypothesis of original fluidity , or even of that of an internal arrangement in nearly spherical strata of equal density . But though the law of the variation of gravity which was originally obtained as a consequence of the hypothesis of primitive fluidity , and was afterwards found by Laplace to hold good , on the condition that the surface be an ellipsoid of revolution as well as a surface of equilibrium , provided only the mass be arranged in nearly spherical strata of equal density , be thus proved to be true whatever be the internal distribution , the question may naturally be asked , Does not the condition that the potential at the surface shall have its actual value require that the internal distribution shall be compatiblewith that of a fluid mass , or at anyrate shall be such that the whole mass shall be arranged in nearly spherical strata of equal density ? Such a question was in fact asked me by an eminent mathematician at the time to which I have alluded . I replied by referring to the well-known property of a sphere , according to which a central mass may be distributed uniformly over its surface without affecting the external attraction , by applying which proposition to a mass such as the Earth we may evidently , without affecting the external attraction , leave a large excentrically situated cavity absolutely vacuous , the matter previously within it having been distributed outside it . It is known further that the mass of a particle may be distributed over any surface whatsoever enclosing the particle without affecting the external attraction , and in this way we see at once that we may leave any internal space we please , however excentrically situated , wholly vacuous ; nor is it necessary in doing so to introduce an infinite density , by distributing the whole mass previously within that space over its surface , since that mass may be conceived to be divided into an infinite number of infinitely small parts , which are respectively distributed over an infinite number of surfaces surrounding the space in question . These considerations , however , though they readily show that the internal distribution may be widely different from any that is compatible with the hypothesis of primitive fluidity , do not lead to the general expression for the internal density . Circumstances have recently recalled my attention to the subject , and I can now indicate the mode of obtaining the general expression required in the case of any given surface . Let the mass be referred to the rectangular axes of x , y , z , and let p be the density , V be the potential of the attraction . Then for any internal point V satisfies , as is well known , the partial differential equation dx2 ++y 4 d2-4rp ... . ( 1 ) or as it may be written for brevity VV=O . This equation may be extended to all space by imagining the body continued infinitely , but having a density which is null outside the limits of the actual body ; and by adopting this convention we need not trouble ourselves about those limits . Conversely , if V be a continuously varying function of x , y , z , which vanishes at an infinite distance , and satisfies the partial differential equation ( 1 ) , V is the potential of the attraction of the mass whose density at the point ( x , y , z ) is p ; or , in other words , vdx'dy'd- ' , ... ... . ( 2 ) where r is the distance between the points ( x , y , z ) and ( x ' , y ' , z ' ) , p ' the density at ( x ' , y ' , z ' ) , and the limits are oo to o , is the complete integral of ( 1 ) subject to the condition that V shall vanish at an infinite distance . This may be proved in different ways ; most directly perhaps by taking the expression for the potential ( U suppose ) which forms the right.hand member of ( 2 ) , substituting for p ' its equivalent -VV ' , V being the same function of x ' , y , z ' that V is of x , y , , and transforming the integral in the manner done by Green* , when we readily find U=V . Suppose now that we have a given closed surface S containing within it all the attracting matter , and that the potential has a given , in general variable , value V0 at the surface . For the portion of space external to S , V is to be determined by the general equation VV=O , subject to the conditions V=Y-V at the surface , and V=O at an infinite distance . We know that the problem of determining V under these circumstances admits of one and but one solution , though it is only for a very limited number of forms of the surface S that the solution can actually be effected . Conceive dV the problem , however , solved , and from the solution let the value of -d v at the surface be found , v being measured outwards along the normal . Now complete V for infinite space by assigning to the space within S any arbitrary but continuous * function we please , subject to the two conditions , 1st , that at the surface it is equal to the given function V ; 2ndly , that it gives for the value ofv at the surface that already got from the solution of the problem referred to in this paragraph . This of course may be done in an infinite number of ways , just as we may in an infinite number of ways join two points in a plane by a continuous curve starting from the two points respectively in given directions , which curve may be either expressed by some algebraical or transcendental equation , or conceived as drawn liberd manu , and thought of independently of any idea of algebraical expression . The function V having been thus assigned to the space internal to S , the equation ( 1 ) gives , according to what we have seen , the most general expression for the density of the internal matter . There is , however , no distinction made in this between positive and negative matter , and if we wish to avoid introducing negative matter we must restrict the function V for the space internal to S to satisfy the imparity d27 d2V d2V d'12 + 0$ . It is easy from the general expression to show , what is already known , that the matter may be distributed in an infinitely thin , and consequently infinitely dense stratum over the surface S , and that such a distribution is determinate . We know that there exists one and but one continuous function appl ing to the space within S which satisfies the ecuation VV=0 , and is equal to VQ at the surface . Call this function V1 . It is to be remarked that the dV dV value of at the surface is not the same as that of d- , V being the exdv dvi ternal potential , though YVand V are there each equal to YV . The argument , it is to be observed , does not assume that the two are different ; it merely avoids assuming that they are the same ; the result will prove that they cannot be the same all over S unless the density , and consequently the potential , be everywhere null , and therefore V0=0 . Now attribute to the interior of Sa function V which is equal to V1 except over a narrow stratum adjacent to S , the thickness of which will in the end be supposed to vanish , within which V is made to deviate from V in such a manner as to render the variaticn of continuous and rapid instead of abrupt . On applying equation ( 1 ) , we see that the density is everywhere null except within this stratum , in which it is very great , and in the limit infinite . For the total quantity of matter contained in any portion of the stratum , we have from ( 1 ) the integration extending over that portion . Let the portion in question be that corresponding to a very small area A of the surface S ; we may suppose it bounded laterally by the ultimately cylindrical surface generated by a normal to S which travels round the perimeter of A. Taking now rectangular coordinates X , p , of which the last is parallel to the normal at one point of A , since V is not changed in form by referring it to a new set of rectangular axes , we have for the mass required 1 _ffffJ d2V ( 1V d2V:rs d d/ +A{L2 ddX"2v }2 Of the differential coefficients within brackets , the last alone becomes infinite when the thickness of the stratum , and consequently the range of integration relatively to X , becomes infinitely small . We have in the limit 'JrT dV dV , j~hV " =d : , / di , both diiferential coefficients having their values belonging to the surface . H ence we have ultimately for the imrass 47r d , v drv THence , if zh be the superficial density , ( lefined as the limit of the mass corresponding to any small portion of the surface divided by the area of that portion , -ht ( i tih/ . ( 3 ) whbichl is the -knownv exprelssion , In assigniln arbitrarily a function V to the interior of S , in order to get the internal density by the application of the formula ( 1 ) , we may if we please discard the second of the conditions which V had to satisfy at the dV , cdv surface , namely , that , '--- ; but in that case to the mass , of finite density , determined by ( 1 ) must be added an infinitely dense and infinitely thin stratum extending over the surface , the finite superficial density of this stratum being given by ( 3 ) . We have seen that the determination of the most general internal arrangement requires the solution of the problem , To determine the potential for space external to S , supposed f free fm attracting matter , in terms of the given potential at the surface ; and the determination of that particular arrangement in which the matter is wholly distributed over the surface , requires further the solution of the same problem for space internal to S. If , however , instead of having merely the potential given at the surface S we had given a particular arrangement of matter within S , and sought the most general rearrangement which should not alter the potential at S , there would have been no preliminary problem to solve , since V , and therefore its differential coefficients , are known -for space generally , and therefore for the surface S , being expressed by triple integrals . Instead of having the attracting matter contained within a closed surface S , and the attraction considered for space external to S , it might have been the reverse , and the same methods would still have been applicable . The problem in this form is more interesting with referelce to electricity than gravitation . II . " On the Integrability of certain Partial Differential Equations proposed by Mr. Airy . " By R. MOON , M.A. , late Fellow of Queen 's College , Cambridge . Communicated by Professor J. J. SYLVEaSTER . Received April 30 , 1867 . ( Abstract . ) The equation -= , +-4-y , ... ( 1 c1y " d/ .v die where a , f. , y are functions of x , includes two equations recently proposed for solution by Mr. Airy , and affords a good illustration of the ordinary incapacity of partial differential equations of the second order for solutions involving arbitrary functions . If the above equation admit of an integral solution containing one or more arbitrary functions , it must be capable of being derived from an equation of the form F(:)v / ( ) =ef ( . , , ) } , e h ... ... . ( 2 )
112682
3701662
On the Integrability of Certain Partial Differential Equations Proposed by Mr. Airy. [Abstract]
486
489
1,866
15
Proceedings of the Royal Society of London
R. Moon
abs
6.0.4
null
null
proceedings
1,860
1,850
1,800
4
42
1,164
http://corpora.clarin-d.uni-saarland.de/surprisal/6.0.3/?id=112682
null
http://www.jstor.org/stable/112682
null
null
Formulae
85.207717
Biography
10.398558
Mathematics
[ 81.385009765625, -38.38547897338867 ]
II . " On the Integrability of certain Partial Differential Equations proposed by Mr. Airy . " By R. MOON , M.A. , late Fellow of Queen 's College , Cambridge . Communicated by Professor J. J. SYLVEaSTER . Received April 30 , 1867 . ( Abstract . ) The equation -= , +-4-y , ... ( 1 c1y " d/ .v die where a , f. , y are functions of x , includes two equations recently proposed for solution by Mr. Airy , and affords a good illustration of the ordinary incapacity of partial differential equations of the second order for solutions involving arbitrary functions . If the above equation admit of an integral solution containing one or more arbitrary functions , it must be capable of being derived from an equation of the form F(:)v / ( ) =ef ( . , , ) } , e h ... ... . ( 2 ) 486 where F and f are definite , and q is arbitrary . From this last we get F'(X ) + F'()_p=q , '(f){f'( ) +f '(z)p } , F'(y ) +F ( z)q='(f){f(y ) +f'(z)q } ; and eliminating o ' between these , we shall arrive at an equation between xyzpq which is the only partial differential equation of the first order free from arbitrary functions which is obtainable from ( 2 ) without assigning to pa definite form . Hence ( 1 ) must be derivable from an equation of the form f(xysp ) = 0 , or of the form 0=q +f(y ) , ... ... . ( 3 ) wheref is definite . Differentiating , we have d2z d2z O-4-f'(y)+f'(z)q+f'(p ) d d ? + f ' ( +f'(p)+ f(Z ) d+ '( dx die +/ '( +/ ) Multiplying the second equation by A ( where A is any function of xyzpq ) and adding , we get ( 1o2 , d2dz + f(p ) +A } ddy +Af'(p ) d+f'(y)+Af'( ) ( 4 ) + ( q+ Ap)f'( ) . If ( 1 ) admits of a solution of the form ( 2 ) , ( 1 ) must be identical with ( 4 ) , or be capable of becoming so by virtue of ( 3 ) . Ience 0=A+f'(p ) , -a2=Af'(p ) , Sp + yT=f'(y ) + Af'( ) +(Ap-f )f'(z ) ... ( 5 ) From the two first we get f'(p)= ? + , A=-T . Hencef must satisfy both the equations f'Cp)h ? ? , }. . ( 6 ) 0 =f ! ( y ) ) ? ~f'( ) -(f ? + ap)f ' ( )(p + J* ) . The first gives us f= F(xyz ) + p , where F is arbitrary . Substituting this value in ( 6 ) , observing that f '(x ) = ''( ) p ( y ) ( f'(z ) we get 0=F'(y ) aF'( -(F + 2)p ) '(z(- " +.+ dO . ( 7 ) But F contains only xyz ; hence , in order that this last equation may hold , the coefficient of p must =0 , i. e. we must have dx(8 ) o=_+2cF'( , )+(3 + ? ... ... ( 8 ) in which case ( 7 ) reduces to 0= F'(y ) aF'(x)--F . F'()-yz ... . . ( 9 ) F must satisfy both ( 8 ) and ( 9 ) . By integration of ( 8 ) we get F=F , ( xy)T + z. Substituting this in ( 9 ) , observing that F'(x)F ' +,2( ) lT d+ F'(y)= ( F ' ) , we get 0 =F'(y ) ? 'F ( x)+ . 10 + 11 ( 23 + ^VpF 2i+ d. y But , since F1 contains x and y only , in order that this may hold we must have the coefficient in it of z= 0 , i. e. 0 d^ . I da 1 " p T , 0d2 ( xa dx ) 2\ ) in which case ( 10 ) becomes =F Fl(y ) a'(x ) +.F , ; a\+ dx FC . whence by integration we get I ipda+ -1-+ida\ ^F2 ( a2 LD ) ( y dx ) where 9 is arbitrary . Hence we get for the first integral of ( 1 ) zOen ( 10 ) is satisfied , I+ -PD da J dv-dx in which h case ( 0 b ecoms2a2 o=q+aP 2 ( )+_ Z+ / . d whea e9 is a whence by ordinary integration we obtain the complete integral of the form , eJ 2u.)-.dx dx We have above a very simple example of a general principle , viz. that in order that a partial differential equation of the second order , or a pair of simultaneous partial differential equations of the first order , may admit of a solution containing arbitrary functions , the coefficients must satisfy a certain equation of condition ; from which it follows that , except in the simplest instances ( in which the terms of the equation of condition vanish ) , there is a moral certainty that such a differential equation or pair of equations which have not been specially selected for the purpose , and whose coefficients do not involve a disposable quantity by which the equation of condition may be satisfied , will not admit of a solution involving arbitrary functions . The equations applicable to the motion of an elastic fluid along the axis of a tube afford a remarkable illustration of the scope of these remarks . Those equations consist of a pair of partial differential equations of the first order involving five variables , viz. y , t , p , v , p ; and it may be shown Opriori , that when derived upon a true theory they must be capable of a solution containing two arbitrary functions ; from which it follows that a third equation will require to be satisfied . For this purpose we have p , the pressure , ready to our hands . From the fact of the existence of the equation of condition not having been suspected by the founders of the theory of fluid-motion , at the same time that it was absolutely necessary for them to assign a form to p , they had recourse for that purpose to an empirical method ; thus , on the one hand , depriving us of the power of satisfying the requirements of the problem , and on the other , abandoning the means for the determination of p which the analysis furnishes . It cannot be matter of surprise that the law of pressure suggested under these circumstances should be entirely erroneous , as ( by two other independent methods , one founded upon purely physical , the other upon purely analytical considerations ) I have elsewhere shown .