bluuebunny/crossref_metadata_2025 huggingface dataset:
The use of fillers in bituminous road surfacings. A study of filler‐binder systems in relation to filler characteristics
Authors: Rigden P. J.
Published: July 2007

The paper describes a study of the fineness characteristics of. a wide range of fillers used in the production of bituminous road surfacings. The object of this study was to find a simple characteristic of the filler which could be directly related to the behaviour of filler‐binder mixtures, both at low filler concentrations which occur in many types of thin surfacing, and at high filler concentrations which occur in dense surfacings of the “asphalt” type. An investigation is then described into the flow properties of a number of filler‐binder systems containing both tar and bitumen binders, over a range of filler concentration from zero to the greatest amount which gave a cohesive mixture. The filler property found to be most simply related to these flow properties is the value of the fractional volume voids in the tightly‐compacted dry filler. The determination of this value is described and it is shown that from it the “optimum binder content” of any filler may be readily calculated. It is also shown that the relation between viscosity and filler concentration of any filler‐binder system may be most simply interpreted if the concentration of filler is expressed in terms of the degree of packing of the filler as calculated from the fractional volume voids.
Thermally reversible strains in plasticized polyvinyl chloride
Authors: Pollett W. F. O.
Published: July 2007

Torsion tests have been used to investigate thermally reversible strain in plasticized p.v.c. in relation to the conditions under which it is produced. The initial set, on cooling after release of the applied strain, increases with the time, temperature and extent of deformation and rapidity of cooling, but under the experimental conditions was almost wholly recoverable on re‐heating. Cooling Under strain increases the initial set, and recovery then begins at the commencement of re‐heating; otherwise it starts at a higher temperature the slower the cooling after release. Recovery per unit temperature rise reaches a maximum just below the straining temperature at a position depending on straining time and rate of cooling, but not on composition within wide limits. Even opposed strains introduced successively at diminishing temperatures are separately recoverable on re‐heating. A qualitative explanation of the phenomena is proposed which assumes the presence of associations covering a wide range of stabilities.
Latent heat of vaporization, temperature and density of liquids
Authors: Bowden S. T. , Jones W. J.
Published: July 2007

Simple relations are given for the variation of the latent heat of vaporization of non‐associated liquids with the absolute temperature and the density. These relations are applicable over ranges of 50° and 100°, respectively, above the boiling point of the liquid. It is shown that the latent heat of vaporization of water is inversely proportional to the square‐root of the absolute temperature for the range 100°‐150°. A relation is also given for the variation of density of non‐associated liquids with temperature.
Copper acetylides
Authors: Brameld V. F. , Clark M. T. , Seyfang A. P.
Published: July 2007

Following an introduction and a brief review of published work on copper acetylides, investigations into conditions of formation and properties of copper acetylides are described. Parts I and II deal with formation from acid and alkaline, cuprous and cupric solutions. Part III concerns the formation of acetylides on the surfaces of copper and copper alloys under varying conditions. Although acetylides cannot be formed in cupric solutions above a certain acid concentration, they can be formed on the surfaces of copper and brasses immersed in such solutions even if the acidity is greatly increased. Explosive acetylides can be formed not only on copper and high‐copper alloys in ammoniacal acetylene atmospheres, but also on copper and brasses containing 50% copper or more, when these have been contaminated with acids or caustic alkalis. Methods are given for the detection of small amounts of copper acetylide.
Salinogenic or chelate forming dyes as analytical reagents
Authors: Steigmann A.
Published: July 2007

The diazoaminogroup (—N=N·NH—) was found to be silver, mercury and cadmium selective. The sulphonamide group (—SO2·NH—) as present in sulphanilamide and other sulpha drugs is similarly reactive. Para diethylaminobenzeneazo chromotropic acid (“chromotropic blue”) was found to be cerium, calcium, magnesium and under certain conditions copper, nickel and cobalt selective. Copper specific and nickel‐selective, is 5‐(p‐nitrobenzeneazo)‐7‐nitroso‐8‐hydroxyquinoline (“oxin violet”). New reactions of nitroso‐R‐acid and photographic reactions of some of the mentioned chemicals are described.
Time viscosity studies of the system groundnut protein‐caustic soda‐water
Authors: Thomson R. H. K. , Johnston A.
Published: July 2007

The change of viscosity with time in the system groundnut protein‐caustic soda‐water has been studied over a limited range of concentrations. The concentrations selected were those which gave viscous solutions without gelation. The viscosity was plotted continuously against time for each concentration for 15 hours at 20°. The results are presented in graphical form and are in accord with the hypothesis that globulins have spheroidal or coiled molecules which unwind or unfold to long chains on reaction with caustic soda, and if the reaction proceeds far enough, break down to smaller molecules.
The control of the PH of jams
Authors: Hinton C. L.
Published: July 2007

The neutralization curves of the acids of fruits and other jam constituents have been determined over the range of interest in jam making, and from them the curves applicable to commercial jams are computed. On the basis of these curves, formula are derived for calculating the quantities of citric acid, sodium bicarbonate, or sodium citrate to be added to change the pmrH of jams by required amounts.
Production of rare earth and thorium compounds from monazite. Part I
Authors: Pilkington E. S. , Wylie A. W.
Published: July 2007

A process is described for the separation of rare earth elements in monazite into the following products : (a) cerium group hydroxides containing thorium hydroxide, (b) crude thorium oxalate. Quantitative aspects of the various methods used to accomplish the separations have been investigated. The process is suitable for large scale operation.
Notes on maize
Authors: Herzka A.
Published: July 2007

One of the ways in which maize is used is as popcorn. To obtain this the maize is expanded and turned inside out by the application of heat j this process is termed the popping of com (= maize). The work described below has been carried out to ascertain (a) why maize pops, and (b) why popping is limited to certain varieties of maize.
The fischer‐tropsch synthesis with cobalt catalysts
Authors: Craxford S. R.
Published: July 2007

An account is given of the more academic aspects of the research work carried out in Germany and elsewhere during the war years, and on this basis a picture of the catalyst and its method of working is developed. The reacting gases reach the catalyst surface directly in atmospheric pressure synthesis, but by solution in and diffusion through the wax that fills the pores of the catalyst in medium pressure synthesis. The cobalt atoms appear to be isolated and do not form part of a cobalt lattice. Reaction by way of chemisorbed carbon atoms‐surface carbide‐is thought to give an array of inter‐acting methylene groups on the surface, and the composition of the products, which are obtained by desorption from this array, depends on the conditions.
The thermal decomposition of triphenylacetic acid and triphenyl‐acetyl chloride
Authors: Scholefield P. G. , Bowden S. T. , Jones W. J.
Published: July 2007

The thermal decomposition of triphenylacetic acid and the corresponding acid chloride has been examined by direct measurement of the carbon dioxide evolved in the former reaction and of the carbon monoxide evolved in the latter. The evolution of gas is small at the melting point of the compounds, but may he readily measured when the reaction takes place at higher temperature cither in the melt or in solution. Equations arc given for calculating the amount of gas evolved from the liquid for each temperature, and from solutions of triphenylacetic acid in triphenylmethane and of triphenylacetyl chloride in triphenylmethyl chloride, diphenyl and triphenylmethane.
The germicidal effects of free and combined sulphur dioxide
Authors: Ingram M.
Published: July 2007

Yeasts have been exposed to SO2 in nutrient solutions with two concentrations of dextrose; chosen so as to induce the same rate of growth in the yeast, but to combine with quite different proportions of the SO2 added. It was found that the behaviour of the yeast was related to the concentration of “free” (i.e. iodinetitratable) SO2, and not to the amounts “ combined “ or added. In another experiment, a correlation was demonstrated between the rate of growth of yeasts in concentrated orange juice and the concentration of free SO2, but not with the combined or total SO2; in this experiment however, larger quantities of free SO2 were involved than in the first.

It is concluded that in relation to the preservative action of SO2 the quantities added and going into combination are irrelevant, such action being exerted only through the proportion remaining “free.” It is nevertheless clear that there are present in fruit juices factors which reduce the effectiveness even of the “free” SO2.
The determination of chlorine in resins obtained from polyvinyi chloride compositions
Authors: Haslam J. , Soppet W. W.
Published: July 2007

A method is described for the determination of chlorine in resins from polyvinyl chloride compositions. It is based on preliminary isolation of the resin by ether extraction of the sample, followed by fusion of the resin in an electrically fired Parr bomb. The solution of the melt is acidified slightly, and the chloride is then titrated potentiometrically with standard silver nitrate solution.
The determination of phenylbromoacetonitrile
Authors: Kinnear A. M.
Published: July 2007

A method is described for the determination of the. lachrymatory constituent of the technical product known as BBC. The method is based upon the reaction of phenylbromoacetonitrile with excess aniline in presence of a non‐polar solvent, aniline hydrobromide being quantitatively precipitated. A study has been made of the relevant chemistry of BBC with the object of discovering impurities likely to cause interference. A procedure has been developed which eliminates all but traces of interfering substances, and includes correction for any which remain.
A method of following the course of the phenol‐formaldehyde reaction
Authors: Finn S. R. , Rogers L. R.
Published: July 2007

The course of the reaction between phenol and formaldehyde has been followed by observing the temperatures at which the reaction mixture just becomes turbid. The effect of temperature, dilution with water and methyl alcohol, the concentration and nature of the catalyst on the course of the reaction has been observed by this means. The method may also be used to judge any chosen end point of the condensation, where only lightly condensed resins are concerned.
South African fish products. Part XXVII. The composition of the liver oils of the basking shark (cetorhinus maximus, gunner) and the spiny shark (echinorhinus spinosus, gmelin)
Authors: Karnovsky M. L. , Rapson W. S. , Schwartz H. M. , Black M. , Van Rensburg N. J.
Published: July 2007

A detailed quantitative study of the saponifiable and unsaponifiable fractions of the liver oils of the basking shark and the spiny shark has been made. The results are considered in the light of a previously postulated relationship1 between the amount and composition of the unsaponifiable fractions and the nature of the fatty acids present. In addition the unsaponifiable fractions of the oils from the flesh and several organs of the basking shark have been analysed.
The inflammability in suspension of mixtures of combustible and incombustible dusts
Authors: Bowes P. C. , Burgoyne J. H. , Rasbash D. J.
Published: July 2007

An account is given or a new laboratory method of determining the least proportion of incombustible dust which must be added to a combustible dust in order that the mixture, when dispersed in any volume of air will not propagate flame. In common with other small‐scale methods depending on the propagation of flame in cold dust/air suspensions, the method seems to give low results as compared with large‐scale gallery tests. It appears to be suitable for comparative measurements, however, and has been used to study the effect of the character and fineness of the incombustible dust on its ability to suppress flame in flour or cork dust/air suspensions. The relative inflammability of a number of combustible dusts has been assessed in terms of the addition of a standard limestone dust required to achieve flame suppression in each case.
The component acids and glycerides of neat's foot oil
Authors: Hilditch T. P. , Shrivastava R. K.
Published: July 2007

The component acids of a specimen of neat's foot oil consisted of myristic 0·7, palmitic 16·9, stearic 2·7, arachidic 0·1, tetra‐decenoic 1·2, hexadecenoic 9·4, oleic 64·4, octadecadienoic 2·3, octadccatrienoic 0·7, and unsaturated C20‐22 acids 1·6% (wt.). The component glycerides, studied after partial separation by low‐temperature crystallization from acetone, were found to include, inter alia, about 35% palmitodiolein, 23% of hexadecenodiolein, 8% of polyethenoid‐diolein, 7% of olcopalmitostearin and probably not much more than 10% of triolein, with minor amounts of other mixed glycerides. The presence of fairly substantial proportions of hexadecenoic acid in neat's foot oil had not been previously noted. The specific utility of the oil as a lubricant cannot, as at one time supposed, be connected with a high content of triolein. The present work suggests the possibility that hexadecenodiolein, which forms nearly one‐quarter of the oil, and perhaps also the di‐oleoglycerides in which the third acyl group is a polyethenoid member of the C15, C20 (or C22) series, may contribute specifically to its lubricant properties.
The preparation of methylpyridines by catalytic methods
Authors: Cullinane N. M. , Chard S. J. , Meatyard R.
Published: July 2007

The action of methyl alcohol on pyridine in the vapour phase in contact with alumina or aluminium silicates gives methylpyridines, including the commercially valuable β‐picoline. The separation of this base from the other homologues of similar boiling‐point can be effected by taking advantage of the fact that it does not condense with m‐nitrobenzaldehyde to form a stilbazole. Small yields only of β‐picoline are obtained by heating (a) ammonia and (b) urea with glycerol in the presence of the same catalysts.
A new method of photographic evaluation in spectrographic analysis
Authors: Argyle A. , Price W. John
Published: July 2007

A simple nomographical method of evaluation of minor constituents is given which, provided that the density values all fall on the straight line portion of the H & D curve of the emulsion used, is independent of gamma variation. When the nomograph is drawn, not only docs it correct for changes in gamma across one plate, but also from plate to plate of any type, thus obviating the need for repeated standardization.
South African fish products. Part XXIX. The composition of the liver oil of the soupfin shark (galeorhinus canis, rond.)
Authors: Karnovskv M. L. , Lategan A. W. , Rapson W. S. , Schwartz H. M.
Published: July 2007

In the soupfin shark the iodine value of the liver oil of the mature fish tends to increase with increase in the oil content of the liver. Determination of the component fatty acids of a composite sample of liver oil from females in fat condition and another from thin (gravid) females showed that this effect is due to the greater degree of unsaturation of the C16, C18, C20 and C22 acids in the fat fish. The component fatty acids of a composite sample of foetus liver oil were also examined. It is suggested that there may be a transference of highly unsaturated C18, C20 and C22 acids from the female to the foetus during gestation. The unsaponifiable fractions of five soupfin shark liver oils were quantitatively examined. In the mature fish, vitamin A, α‐glyceryl ethers and sterols are major components of the unsaponifiable fraction, whereas in the foetus, sterols predominate. Evidence for the presence of fatty alcohols in the unsaponifiable fraction of the liver oils from both the foetus and the mature fish is presented.
The composition of seed fats of west Indian citrus fruits
Authors: Dunn H. C. , Hilditch T. P. , Riley J. P.
Published: July 2007

The fatty oils which form about 40% of the dried seeds of West Indian grape fruits, oranges and limes have been studied with respect to their component acids and glycerides. The mixed fatty acids of each seed oil arc broadly similar in their content of 23‐25% of palmitic, 5‐10% of stearic, nearly 40% of Unoleic and about 20‐25% of oleic acid, with in addition a few per cent of linolenic acid. Apart from the last‐named acid, there is considerable resemblance between the component acids of the Citrus seed oils and those of cottonseed oil. This resemblance extends also to the constituent mixed glycerides of the oils. The Citrus seed oils are of good quality in the raw condition and are readily refined and deodorized to give oils of high edible quality. The latter, in view of the presence of some linolenic glycerides, would be expected to be more prone to oxidative rancidity than cottonseed oil, but by partial hydrogenation the Citrus seed oils yield soft solid fats which when refined and deodorized could form excellent lard substitutes. The quantities of Citrus seeds available technically, however, may not be sufficiently large to permit the oils to be of practical interest to the edible fat industry.
Studies in selective extraction and adsorption. I. Selective solvents for ethylene chlorohydrin
Authors: Weizmann Ch. , Bergmann E. , Chandley E. F. , Steiner H. , Sulzbacher M. , Zimkin E.
Published: July 2007

The isolation of pure water‐free ethylene chlorohydrin from its approximately 8% aqueous solution can be achieved by extraction with selective solvents. A systematic study of various groups of organic compounds shows that aldehydes, ketones, and esters represent the most suitable solvents. In each group, a definite maximum of efficiency exists. The preparation of a number of solvents is described.
The estimation of impurities in tetryl (2:4:6‐trinitrophenylmethyl‐ nitramine)
Authors: Brownlie I. A. , Cumming W. M.
Published: July 2007

A colorimetric method for the quantitative estimation of 2:3:4: 6‐tetranitrophenylmethylnitramine, in presence of 2 :4 : 6‐trinitrophenylmethylnitraminej/has been devised, and its accuracy has been estimated using as the standard a spectrographic method of estimation. These methods are as accurate as, and more rapid than, existing methods of estimation. The spectrographic method is particularly valuable in detecting the presence of impurities in 2:4: 6‐trinitrophenylmethylnitramine.
The anodic oxidation of coal. Part III. Examination of the water‐soluble acids
Authors: Belcher R.
Published: July 2007

The water‐soluble acids obtained by the oxidation of the Melton‐field vitrain at a copper anode, have been subjected to a detailed examination with the object of isolating recognizable products. Chromatographic methods of separation proved unsuccessful. The two fractions obtained after separation into soluble and insoluble ammonium salts were converted to the methyl esters and distilled in vacuo. Oxalic acid, mellitic acid, hemimellitic acid and iso‐phthalic acid were isolated, but only oxalic acid was obtained in appreciable amounts. The bulk of the water‐soluble acids thus remain uncharacterized. Decarboxylation, however, yielded benzo‐phenone, diphenyl and benzene which arc typical products from the decarboxylation of benzene carboxylic acids. In general, these acids appear to be similar in nature to the acids obtained by alkaline permanganate oxidation of coal, the greater portion of which has never been characterized.
The thermal decomposition of pentaerythritol tetranitrate, nitroglycerin, ethylenediamine dinitrate and ammonium nitrate
Authors: Robertson A. J. B.
Published: July 2007

The decomposition of nitroglycerin and ammonium nitrate follows the unimolecular equation. That of pentaerythritol tetranitrate shows slight autocatalysis and ethylenediamine dinitrate shows considerable autocatalysis. Normal Arrhenius expressions for the decomposition rate were obtained for the two nitrates, but the frequency factor for the two nitric esters is extremely large. With pentaerythritol tetranitrate a significant diminution of the frequency factor in dilute solution was ascribed to reaction chains having a short length dependent on temperature. Analyses of the gaseous products were made including the use of a flow method with pentaerythritol tetranitrate.
Production of a metallurgical coke from the resin of wallaba wood (eperua sp.)
Authors: Farmer R. H. , Campbell W. G.
Published: July 2007

The wood of the wallaba tree (Eperua sp.) of British Guiana contains a high proportion of an alcohol‐soluble resin of a phenolic type. It is shown that this resin can be converted by controlled destructive distillation into a metallurgical coke of high purity and good physical properties. The volatile products of the distillation include a complex mixture of phenols which has useful fungicidal properties, and a combustible gas.
On the determination of traces of organic bases in benzol and the like
Authors: Wiison H. N.
Published: July 2007

A method is described for the determination of traces of basic nitrogen in hydrocarbons and the like by titration with perchloric acid in glacial acetic acid in the complete absence of water. Enough glacial acetic acid is added to the sample to keep perchlorates of bases in solution, and methyl violet is used as indicator.
The reduction of antimony solutions with metallic nickel
Authors: Holness H.
Published: July 2007

Conditions have been established for the most efficient use of nickel in the reduction of hydrochloric acid solutions of antimony. The variation of this reduction with time, temperature, acid concentration, amount of nickel and concentration of antimony has been studied. Using 5·0 g. of fine nickel powder, solutions containing up to 1·5 g. of antimony in 100 ml. of dilute HCl (1 ‐‐‐ 3) were reduced in 20 minutes, provided the solution was undisturbed and was heated on a water bath. Experiments using sheet nickel in place of powder are described and a suggestion offered for some of the phenomena observed.
A reflectance method for determining the “ink absorbency” of paper
Authors: Bowles R. F. , Sllcox Aileen
Published: July 2007

The Vandercook hand proofing press, the PATRA printing shell and a reflectometer have been used together with an ink of fixed composition to measure the ink absorbency of any paper as a function of the surface reflectance of a film of ink printed on the paper. The absorbency characteristics of the paper are referred to the constants: initial penctration, rate of absorption, and residual reflectance.
The kinetics of package life. IV. Diffusivity
Authors: Oswin C. R.
Published: July 2007

A criterion is derived empirically from tabular solutions of the Diffusion Law to show whether the rate of change of the moisture content of a wrapped hygroscopic commodity, stored in an atmosphere with which it is not in equilibrium, is controlled predominantly by the resistance of the superficial wrapper to the passage of water or by the bulk impedance of the commodity. Measurements on some typical small packets indicate that a surface resistance is the predominant factor, even with unwrapped commodities.
On the extinction‐coefficient: particle size relationship for fine mineral powders
Authors: Rose H. E. , French C. C. J.
Published: July 2007

In this work a short account is given of researches into the measurement of the size characteristics of mineral powders by photo‐extinction methods which have led to an experimentally derived curve relating the extinction coefficient for a suspension to the size of particle of the material in suspension, for the size range 0‐50 microns. While it is not claimed that the validity of this curve is rigidly established, it is believed that it is considerably more reliable than any previously suggested and to have an accuracy sufficient for many industrial purposes.
Gas drying by calcium chloride solutions: The mechanism of transfer
Authors: Thurston E. F.
Published: July 2007

Experiments have been carried out in a small laboratory packed tower and in a wetted wall column to determine the respective contributions of the gas and liquid films to the transfer of water vapour from moist air into strong solutions of calcium chloride. Comparative tests were also made on the absorption of ammonia from air‐ammonia mixtures into dilute sulphuric acid in the wetted wall column. The experimental results have shown that in normal conditions gas drying by calcium chloride solutions may be regarded as a case of predominantly gas film limitation. This information may be used in the design of gas or air drying towers using strong calcium chloride solution as desiccant.
A study of some chemical reactions employed in photometric analysis
Authors: Davis H. C. , Bacon A.
Published: July 2007

The paper describes an investigation into a number of the chemical reactions employed in photometric analysis for the determination of silicon, manganese, chromium, nickel, vanadium, titanium, copper, iron and molybdenum. The influence of a large number of variables has been studied in order to establish the optimum solution conditions for the development of stable and reproducible colours irrespective of the class of material in which the clement to be determined may occur.
Fluorination of organic compounds with anhydrous hydrogen fluoride. PART III. Uncatalysed fluorinations
Authors: Brown J. H. , Whalley W. B.
Published: July 2007

Carbon tetrachloride, as‐tetrachloroethane, pentachloroethane and hexachloropropylene have been fluorinated by heating with anhydrous hydrogen fluoride. The reaction mechanism is discussed.
The large scale development of the aerated retting process in great britain
Authors: Gibson M.
Published: July 2007

Aerated retting tanks erected by the Ministry of Supply

At the time of development all flax mills were administered by the Ministry of Supply. As from April 1, 1946, responsibility for the Raw Materials Department and Controls other than in the field of engineering was transferred from the Ministry of Supply to the Board of Trade.

at H.M. Norfolk Flax Establishment and at other flax mills and their method of operation arc described. Practical difficulties of aeration and temperature control are discussed.
A method of selecting foam inhibitors
Authors: Robinson J. V. , Woods W. W.
Published: July 2007

Most foam inhibitors arc insoluble. A criterion is described for selecting foam inhibitors {from insoluble liquids3which form emulsions with the liquid to be defoamed. By determining the surface tensions of the liquid to be defoamed and of the additive saturated with that liquid and the interfacial tension between them, a rupture coefficient may be calculated. A high positive rupture coefficient is characteristic of a liquid with a high foam inhibiting ability for the specified foaming liquid. “A negative rupture coefficient is characteristic of liquids which will not reduce foaming. Fifty‐four experimental cases are cited, for three foaming systems, to which the principle has been applied with high correlation. A mechanism of defoaming is described. Bubble coalescence rather than bubble rupture at the top of the foam is emphasized. It is shown that a spread film of a foam inhibitor on the surface of the foaming liquid may actually stabilize bubbles at the surface, although promoting rapid coalescence.
Some metallic compounds of unsaturated fatty acids: Their preparation and properties with special reference to the influence of the acidic group in autoxidation processes
Authors: Skellon J. M. , Spence J. W.
Published: July 2007

The experimental preparation of certain less common, pure metallic compounds of selected unsaturated fatty acids is described. The metal content of these compounds has been determined, and the probability that certain of these derivatives may be physical complexes, rather than true chemical compounds, is discussed. The general properties of the derivatives arc described, particularly their catalytic influence in autoxidation of unsaturated mono‐ethenoid acids. The influence of the nature and configuration of the acid radical in each autoxidation is discussed.
A new method for determination of small amounts of molybdenum in plants
Authors: Piper C. S. , Beckwith R. S.
Published: July 2007

Molybdenum forms a green precipitate with dithiol (4‐methyl‐1: 2‐dimercaptobenzene) in acid solutions and this precipitate is soluble in amyl acetate, giving an intensely coloured solution. This reaction is the basis for an extractive method for the determination of small amounts of molybdenum, of the order of 0.2 to 25 μg., occurring in plant materials. The sample is digested with nitric, sulphuric and perchloric acids, and copper extracted with dithizone and determined as usual, if so desired. The digest is then acidified and molybdenum, along with certain other metals, extracted by means of cupferron and chloroform. After the destruction of cupferron the molybdenum‐dithiol complex is precipitated, extracted into amyl acetate and its absorption determined in a photoelectric colorimeter. The method is accurate and extremely sensitive. Since it enables the determination of both copper and molybdenum in the same digest, it represents an economy of time and reagents when both determinations are required.
The pyrethrin contents of undried flowers, chrysanthemum cinera‐riaefolium, determined by extraction with petrol ether
Authors: Edwards M. G.
Published: July 2007

A method is described of quantitatively extracting the pyrethrins from undried pyrethrum flowers, using petrol ether only as solvent. The flowers are ground in a rod mill with the solvent and then extracted in three stages. Samples of the same flowers are dried by natural and by the most favourable artificial means, and a third sample in a commercial drier. The total pyrethrins in the undried and the dried flowers are compared on a moisture‐free basis. The same procedure is applied to three strains of Kenya‐grown flowers.
Public health aspect of metallic contaminants in food
Authors: Monier‐Williams G. W.
Published: July 2007

The paper discusses the toxic effects due to the intake of arsenic, lead, copper, zinc, and tin, and mentions some of the findings, recommendations, and proposals of authorities in connexion with public health.
Aluminium and fruit juices
Authors: Gilroy P. E. , Champion F. A.
Published: July 2007

The interaction of fruit juices and aluminium has been investigated to provide a basis for the development of the uses of aluminium in the industry. It has been found that pure aluminium and Al‐Mn and Al‐Mg alloys are eminently suitable for the transport and storage of apple and blackcurrant juices. They are also suitable for citrus juices if the sulphur dioxide preservative is suitably controlled.
The temperature sensitivity of the system plasticizer‐polymer
Authors: Jones H.
Published: July 2007

Generally, in this paper, there are reviewed some of the factors influencing the properties of plastics, and additional evidence is provided through data on the rebound resilience; temperature relationships, for the current ideas on the plasticizer‐polymer interaction. Probably through the inferiority of mechanical tests compared with those of an electrical nature (Wurstlin, loc. cit.), the data are not so precise as to be quantitative but at least are of such a nature as to give further suport to the general theory of plasticizer viscosity and especially the relationship between the temperature dependence of plasticizer viscosity and that of plasticized compounds.
The insoluble matter of coal tar. IV. Coal tar resins
Authors: Green S. J. , Mukherji S. M.
Published: July 2007

The So‐called coal tar resins are defined and their preparation from vertical retort tar and pitch is described. The resins are divided into resinols, resinoic acids, resinenes, and resinamines, about 99% consisting of resinenes. The importance of dxygen in these compounds is discussed. Further fractionation of resinencs by precipitation and chromatography and the analyses of the fractions are reported. It appears that the resinols react during the distillation of tar to give higher molccular wegiht resinous compounds.
The activation of alumina
Authors: Taylor R. J.
Published: July 2007

An investigation has been made of the physical transformations with occur when γ aluminium trihydrate (gibbsite) is dehydrated by heat treatment, and the effect such transformations have on the adsorption activity and porosity of the material. Dehydration proceeds according to the scheme: trihydrate → monohydrate → alumina, no dihydrate being formed. Between 225° and 500° positions of equilibrium are established between the monohydrate and alumina and the adsorption activity is directly related to the degree of conversion to γ alumina. At 500° and higher temperatures, the material is converted wholly to γ alumina. This, unlike the tri‐ and monohydrates cannot be completely defined as it is a transitional product in a heat‐controlled solid reaction, its state being at first highly disordered but rearranging to an orderly state as the reaction proceeds. The adsorption activity of the material is directly related to the state of disorder. The particle size distribution of the material is unaffected by the heat treatment which it receives, hence the porosity of the final product can be controlled by selection of the starting material. Aluminas covering a wide range of activities can be prepared by simple heat treatment of the hydrate.
Inflammability limits of ammonia, nitrous oxide and air
Authors: Jones Elwyn , Kerr James C.
Published: July 2007

With a view to exploring the possibility of eliminating the explosion hazard in the manufacture of sodium azide, the limits of inflammability were de ermined in the upward, horizontal and downward directions for all mixtures of ammonia, nitrous oxide and air at normal Temperature and pressure in 2 in, diameter rubes. The range of inflammability was found to be greatest in mixtures containing no air, being 2·6‐71·9% of ammonia for upward propagation, 5·1‐71·6% for horizontal propagation and 6·8‐71·0% for downward propagation. Addition of air caused contraction of the inflammable range at both ends roughly in proportion to the amount of air added. The limits for mixtures of ammonia and nitrous oxide were also determined (a) in 3 in, diameter tubes to indicate the general effect of cross‐sectional area and (b) at 150° and 250° to show the effect of temperature. An increase in either the tube diameter or the temperature produced a slight widening of the limits. Mixtures of ammonia, nitrous oxide and air appeared to obey Le Chatelier's limit rule except for some discrepancy affecting lower limit mixtures. Other evidence confirmed the abnormal behaviour of nitrous oxide containing small amounts of ammonia. AS these mixtures were liable to explode violently, although apparently below the limit for normal flame propagation, their anomalous behaviour is attributed to the exothermic decomposition of nitrous oxide, probably catalysed by the presence of small amounts of ammonia. This reaction appeared to propagate by a mechanism more akin to detonation than deflagration.
The essential oil of pittosporum eugenoides
Authors: Carter C. L. , Heazlewood W. V.
Published: July 2007

The essential oil of the Pittosporum eugenoides, indigenous to New Zealand has been examined, and has been shown to be remarkable for the unusually high content (60°) of liquid paraffin which has been identified at n‐nonane.
A new method of high accuracy for the calibration of reference standard hydrometers
Authors: Cuckow F. W.
Published: July 2007

In this method, standard hydrometers are weighed first in air and then when immersed to the level of the graduation mark in question in xylene of determined density. The density of a liquid which would cause the hydrometer to float with this mark in the plane of the level surface of the liquid is calculated, essentially by linear extrapolation, from these weights and the associated densities of air and xylene. Further weighings with different degrees of immersion enable calibrations to be made at a number of points on the hydrometer scale in quick succession, the working liquid remaining nominally unchanged in density and temperature throughout. By comparison, the basic method of working, employing a freely floating hydrometer, calls for a liquid of different density for each point to be calibrated. Calibrations are made exactly at graduation marks.

The rate of working of the present method is at least four times higher than that of the basic method and an intercomparison of calibrations effected by the two methods shows that there is no detectable loss of accuracy. An open scale hydrometer, which can be read to 0·00000I g./ml., is described for observing the density of the xylene. A nomogram is described for computing the surface tension factors of hydrometers in terms of their weight.
The determination of combined carbon in cast iron by means of the spekker photo‐electric absorptiometer
Authors: Harrison T. S.
Published: July 2007

The determination of combined carbon in cast iron may be completed absorptiometrically since Beer's Law is obeyed. As the intensity of colour produced by a given sample varies with conditions, e.g., acid concentration and time of heating the solution, a standard must be included in each batch of determinations. The optimum conditions for colour development are noted. Colour stability is good.
The component fatty acids and glycerides of dhupa fat
Authors: Balxca M. N. , Meara M. L.
Published: July 2007

The Component fatty acids and glycerides of Dhupa fat have been determined by a combination of the low‐temperature crystallization, lead salt separation, and spectrophotometric techniques. The major Component fatty acids of a number of specimens range from palmitic 10‐13, steam 39‐45, oleic 37‐48% (wt.) with minor amounts of myristic, arachidic, hexadecenoic, linoleic and linolenic acids. Comparison of Dhupa fatty acids with those of the seed fats of other members of the same botanical family indicates a general similarity in stearic and oleic acid contents, palmitic acid being more variable. Component glycerides arc similar with respect to the total amounts of mono‐unsaturated and di‐unsaturated glycerides present, but differences arc observed in some of the individual mixed glycerides, notably oleopalmitostearin and oleudipalmitins in the palmito‐glyceride contents. Dhupa fat, like other seed fats of the Dipterocarpaceae conforms very closely to the rule of even distribution.
The chemist in the flour mill
Authors: Herd Dr. C. W.
Published: July 2007

A lecture given to students explaining the position of a Chemist in a Flour Mill, his relationship with the managerial and operating staff, purchasing departments and sales departments. In addition to the laboratory work, first hand experience must be obtaincd of the milling processes and of the consumer trades. In addition to the normal chemical examination of products, physical (rheological) methods are used for measuring dough characteristics. Vitamins and trace elements become routine practice in a flour mill laboratory, and the routine running of the mill flow can be checked by laboratory tests and experimental milling. Thorough research into the milling processes is advocated.
Sodium nitrite as an inhibitor against the attack of sea water on steel. Part I. The influence of sodium nitrite on the area and intensity of attack
Authors: Wyllie By D. , Cheesman G. C. N.
Published: July 2007

The prevention by sodium nitrite of the attack of sea water on steel has been studied in two ways.

(a) Observation of the extent and nature of corrosion of mild steel specimens partially immersed in sea water containing nitrite.

(b) Measurement of the corrosion currents using a divided cell.

The appearance of a widespread brown discolouration on the steel at the higher nitrate concentrations is discussed and a catalytic mechanism is suggested for the inhibiting action of nitrite.

The effect of mixing phosphates and nitrite is reported.
Determination of coating weights on electrolytic tinplate
Authors: Liebmann H. , Price J. W. , Thompson S. H.
Published: July 2007

Commercial electrolytic flow‐brightened tinplate of nominal 8 oz. per basis box coating weight is shown to contain a tin‐iron alloy at the interface of the tin and the steel base. The extent of this alloy layer has been determined and a suitable correction is suggested for coating weight determinations on this material by loss of weight in antimony chloride‐hydrochloric acid.

This correction is an approximate one, and its value may be influenced by the nature ot the coating process.
Seasonal variation in chemical composition of some of the littoral seaweeds common to scotland. Part II. Fucus serratus. Fucus Vesiculosus. Fucus spiralis and pelvetia canaliculata
Authors: Black W. A. P.
Published: July 2007

In previous communications,1,2,3 the seasonal variation over a period of two years in the ash, iodine, crude protein, mannitol, laminarin and alginic acid contents of the Laminariaceae common to Scotland, has been reported, while in. a later paper,4 the variations in the above constituents were given for the common littoral seaweed Ascophyllum nodosum. The work has now been extended to include the other common littoral algae, namely, Fucus serratus, Fucus vesiculosus, Fucus spiralis and Pelvetia canaliculata and the results have been correlated with the depth of immersion of these algae.
Some data on palestine olives and olive oil
Authors: Puffeles M.
Published: July 2007

(1) Field experiments have shown that varying manurial treatment combined with proper irrigation does not increase the oil and protein content of Palestine olives up to the standard of other Mediterranean brands.

(2) Careful picking, selecting, washing and pressing of the olives under hygienic conditions produces an oil of low acidity.

(3) Dark colouring may be avoided by employing a suitable pressing process whereby the crushing of olives and maceration of cells containing the colouring matter is prevented. A lower yield is thus obtained, which may, however, be increased by employing a corresponding higher pressure.

(4) Rancidity can be avoided by storage of the oil in air‐tight containers filled to capacity and kept in a dark, cool place.
The preparation of diphenylchloroarsine and diphenylcyan oarsine from phenylhydrazine
Authors: Barker R. L. , Booth E. , Jones W. E. , Woodward F. N.
Published: July 2007

Diphenylchloroarsine is readily obtainable in good yield, together with small quantities of phyenyldichloroarsine and triphenylarsine, by oxidation of phenylhydrazine with arsenic acid in presence of a suitable catalyst, followed by treatment with hydrochloric acid. Diphenylcyanoarsine can be prepared in excellent yield either by treatment of the chloro‐compound with potassium cyanide or the intermediate diphenylarsenoxide with hydrocyanic acid.
The preparation of n‐methyldiethanolamine and Nmethyl‐2:2′‐ dichlorodiethylamine
Authors: Abrams J. T. , Barker R. L. , Jones W. E. , Val‐Lender H. W. , Woodward F. N.
Published: July 2007

Optimum conditions have been determined for the preparation of N‐methyldiethanolamine, without serious contamination by higher homologues, by condensation of ethylene oxide with aqueous methylamine: 1The conversion of the diol into N‐methyl‐2: 2′‐dichlorodiethylamine has also been investigated.
The chemistry of bacterial cell division
Authors: Webb M.
Published: July 2007

A brief review of cytological studies of bacterial cell division is followed by a description of preliminary investigations of the chemical nature of factors which, in complex media, influence the division process. In these, magnesium is shown to be essential for the normal cell division of both Gram positive and Gram negative rod‐shaped eubacteria, but in significantly different amounts.

In simple synthetic media, magnesium is also essential for the synthesis of bacterial protoplasm, and in the complete absence of this ion, eubacteria fail to grow. The magnesium requirements of Gram positive organisms are about ten times as great as the requirements of Gram negatives. This difference is attributed to the fact that the former also incorporate magnesium into their structure.

The significance of these findings and the observed differences in cell division of the cocci and rod‐shaped organisms arc discussed.
The weissenberg effect in sweetened condensed milk
Authors: Reiner M. , Blair G. W. Scott , Hawley H. B.
Published: July 2007

When a vertical rod is rotated in certain over‐aged samples of sweetened condensed milk, the milk climbs up the rod. When a disc is rotated near the bottom of the beaker containing the sample, the liquid is drawn radially towards the centre.

It is suggested that these phenomena, commonly called “Weissen‐berg Effects,” are caused, in the case of condensed milk, by an uncoiling of globular protein molecules as a result of denaturation.

Samples showing Weissenberg effects arc sometimes also thixotropic.
Water‐soluble cellulose ethers as emulsifying agents
Authors: Morrison R. I. , Campbell B.
Published: July 2007

The emulsifying powers of various water‐soluble cellulose ethers for mineral and vegetable oils are compared. The advantages of mixtures of sodium carboxymethyl cellulose with other water‐soluble cellulose ethers in producing improved emulsions with reduced foam are shown. Consideration is given to the relative interfacial tensions of methyl ethyl cellulose and sodium carboxymethyl cellulose and to the effects of temperature and hydrogen ion concentration on emulsions prepared from them.
The low‐temperature vacuum drying process as applied to green peas. Part II
Authors: Ede A. J.
Published: July 2007

The effects of vapour pressure, rate of heating, and thickness of layer on the temperature and ultimate quality of peas dried in vacuo on a heated tray have been studied experimentally. Higher temperatures and rates of heating than were formerly deemed advisable hive given good results.
The propagation of exothermic reactions in solid systems, part II. Heats of reaction and rates of burning
Authors: Spice J. E. , Staveley L. A. K.
Published: July 2007

Measurements have been made of the linear rate of the self‐propagating reaction and of the heat of this reaction in compressed binary solid mixtures of an oxidizing and a reducing agent. The thermochemical results have been used to draw conclusions about the chemistry of the reactions involved and about the maximum temperatures reached during burning. The dependence of the rate of reaction on the heat it evolves is discussed, and an explanation given of the fact that the rate usually reaches its maximum at a higher (and never at a lower) percentage of reducing agent than that at which the heat of burning has its greatest value.