New-York tribune., 1870-10-01
SCIENTIFIC NOTES.

Tue PHTHALMOTROPE-This name his
been gwen to machine invented By DIR. Donders Of
Utrecht. for eucdatiDg the moyemens OF the eye-bii-
By OF it the mathematical analysis male by Pf2,
Helmholtz Of the ocular movements may DO pfaCcaiy
demonstrated
HYDRkTF OF CHLORAL-Recent medical jour
mails report fayorsby the OF the hyrate OF choral
for the purpose Of alaying brain excitement snd pro
ducing sleep INDUCES sleep with more certainty than
Dpium and without tie nlu1Ou, effects resulting rom
the Latter h- curative properties, but on account
Of ~ quoting influence 1t has been called tA' hins '
narcotics.
OK THE BREADTH OF SPECTRAL BANDS
Lppich has given ia Poggendorf's AHnder an explain
alton Of the broadening and other variations OF tho
spectral lines Of luminous gases. which he 1scrss 70
changes In temperature Ihe law ae clans 70 l', % ~
lengths which correspond to the borders oi any sec
in the gas but in different the ratio u directly
the square roots OF absolute temperature ana III
Versey as the square roots or their deisities
PHoTOGRAPHIsG THE SUE.-Prot. Winlock
ia no engaged taking pictures Of the sun Of some
what novel plan. He single lens Obeot glass; "
inches diameter. having focal length Of 30 inches,
made by Clark Of crown sllss ana corrected foT sper
ARTIFICIAL star. tuiS
OF the telescope points 10 the North and the image OF he
run run Is tnpow " nor or baokened On one side
cause that done the heat Of the sun distorted
the telescope 30 that when thrown dust
s shaken the plate, frequently Is tpe case I'D Inc
usual way Of working.
AMORPHoUs SILICA FOR FIXING PIGMENTS.-
DR. NJ Reimann describes DtngIers Poigtechne Jour
nal series of experiments made with the view tn apply
amosphous SILICA for absorng che solutions OF fuchine,
anaine blue &C. and 10 use the coiored powder 80 pre-
pared AS pigment various materials. The SILICA Is
prepared by precpitatng solution OF water ls-
cate Of soda potash with acid and collecting wash
ing and drying the preclptate in the ordinary way
Glass arst superhclay acted upon by hydronuoic ACID
and next mOrdanted, "A Ia usual for cotton assumes,
when submitted TO the processes ~ use Tot dyeng NOR
similar cOlOs precisely that hber; the author states
that thio effect IA caused by the amorphous scs con
tanned the glass and made effective by the hydronuono
acid.
Woorz OR INDIAN SrEEL.-Dr. Rammelsbers
gives in Berlin journal the result of his analysis of
steel bar certified to Indian steel by the late
East Indian Company and deposited IN the Museum OF
iron 1t contained the following substances gwen IN
thousandths OF one per cent Caroon' 9'o' s, sllsl,
ol6 phosphorus G 'aPn nn mn S n y ts - s.eemen
since the Messrs Faraday and 5todart W no made
neenI,ar Qualities OF this steel we're due scium and
aluminium, The specific grayty 1I tae specimen used
MIRAGE IN THE BRITISH CHANNEL.-Mr-
Thomas Waring gives In The Meteorological Magazine,
the following description Of mirage OF unusual sple-
dor
.ig. 20 i1rnser ui,a- phenomenon :, striking
latitude. rare that SIN seTSpei TO 'end 700 s' sosoua % ;,
snd the baromeer steady % There bad been sgE g fog
sooa me We otsIs S6rye over The mall iaad u.r I
Section sss %s SsSs Of T % .o ,aa SoSs S & 1n & a
visible round he whole houso The sna, AleTn[ Glrra'' Ter
poiute outlying rocks csppd wih inverted images II ,beu,,
Stone. The ortseh rocE. .Lcb pevo isA vr,
~ ,hes lshsSoases pe1t-i appearance The sht
houses were drawn os INTO colossal % eaa "a Nv ~'S @ ' .
shs sailing KEEL apsai ooso se ar salse .r
Ss. ,sn. ressd ser- beSs Tfs
northern Gaeru.ey the -Od low. rl
found It hard 70 0.T, rSfn'v s,., We s e,Se' .. f
ssooo, '0"s x.r, dyis7 irou ss4 other by aSrou .,s
osDd nesred Guernsey he picture became '' dsnd -
meanwhile the mg, beconns moe wooiea sou e'e A!ei
Herr the ehf were na.aad % an P9n, si S @ @
fascinating gaps b.te oOann, soe ~,
roeL ehs. With %, ds aosns eese.h 'a,a Es als& & CS
than three ssu,s the paaosns Of ~ooen grsday iSa
oaS Or MS hung low IL he nora east NAV s ,t,.
Of g Tss.5s DSf. % sis ss to-, "a % a .Ais " % s ss.is
TIE SCARLET FEvER.-From accounts oi the
havoc made by scarlet fever IN every part oi thS
country we have long regarded It ~ the gfeSt73'
OF our race Uake most cOntaeoUs dlsehs7 - ~ t,h
leaves those who said to have r. & All oy ii
pressions arr conurmed by the foileNn
Tbs British AedloaI Journal, sbich Wal suNs az
thSnseitul persons. ..s - ~ " ss7 oug - ,sei
Bag ~. s's y. sn .ss Ss'iaa uSuSs
data ,,s ssng but -. ,.t In 40 ss ns6.
siSs 1aT: 1ao. a .sros " s'.S.s S' .s's
e,st .aa @ a. s.Is bae asgrssis "a roald
aaassr. 5000 s.'"'. se a, ID ;s ,s. s' s Sh., y
g.sss sss ss De- s..es.. .a.lsa Ssi a4 n, lL s.as.i
0. me so s,ssts ss S... % ss the G M ys .af
e. .s, ,,.s. .s 's. and S.S.SS Snr !, os natalie.
.ps s,. iss ), ..t psr,.sn ." 1rOl'a Goa
not the votaries science 10 make sysemato
and United enft 10 provide trsworthy means DON lo
~ entieD ana cure OF scarlet feverf We have heard
% cares By Of sulphite Of soda,
ic acid and other antisepo preparations Dut there
s.sns ans disaass and there will be until tho
nuss OF aud ts have been made the sn2ect OF
searching aud exhaustive series Of 'eiepfho 'n''