bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies in coal tar bases. I. Separation of β‐ and γ picolines and 2:6‐lutidine
Authors: Coulson E. A. , Jones J. Idris 
Published: July 2007

AbstractTar base fractions commonly described as “commercial β‐picoline” are mixtures containing β‐ and γ‐picoline and 2 : 6‐lutidine in variable, if usually roughly equal proportions. Many methods for the separation of one or more of the individual components have been proposed yet few are suitable for commercial exploitation. In the present paper it is shown that by azeotropic fractional distillation the three bases may be readily separated in purities of 95‐98% and with little loss, if acetic or propionic acids are used as azeotropic‐formers, and it is possible to recover for re‐use the acids from the separate base‐acid azeotropes with the aid of a suitable hydrocarbon entrainer.It is also shown that the hydrochlorides of the bases differ very markedly in physical properties and can be easily separated.Pure specimens of the three bases were obtained by fractional freezing of 95‐88% pure materials : 2 : 6‐lutidine, b.p. 144°, f.p. −5·97°; β‐picoline b.p. 1447middot;0°, f.p. −177middot;77°; γ‐picoline b.p. 145·37°, f.p. + 47middot;3°.
Determination of plastic and brittle states of “pool” bitumens
Authors: Lethersich W. 
Published: July 2007

AbstractThis paper deals with the determination of the plastic and brittle states of bitumens by means of three mechanical tests, viz., tensile strength, ductility and impact.Brittleness is defined us failure due to the hydrostatic component of stress whereas plastic failure is duo to the shear component. This definition leads to suitable tests for brittleness of materials.The ductility teat is applicable to the determination of the strain which the material can conveniently accommodate, whereas the tensile strength test is directly applicable to the matter under consideration, since brittleness deepends on rate of loading and this factor is controlled in this form of test.Impact tests show that all the bitumens tested are brittle when rapidly loaded; the most satisfactory criterion here is the impact energy or what may be determined the brittle strength.
Dehydration of magnesium chloride
Authors: Gaskin J. G. N. 
Published: July 2007

AbstractAn examination of the vapours evolved during the heating of magnesium chloride in the presence of ammonium chloride has shown that hydrolysis of the magnesium chloride is not prevented by the presence of the ammonium chloride. The production of anhydrous magnesium chloride is shown to be due to a second reaction occurring at a somewhat higher temperature between the basic product of the hydrolysis and the amonium monium chloride. Anhydrous magnesium chloride may be prepared from a basic chloride, the hydroxide or the oxide of magnesium by heating with ammonium chloride.
A comparison of methyl bromide and hydrogen cyanide for the fumigation of empty bags in barges
Authors: Brown W. Burns , Lewis S. E. 
Published: July 2007

AbstractDuring two trial famigations of empty bags in barges with methyl bromide, the penetration of this gas was studied by the measurement of gas concentrations. In the second trial, the loaded barge was also treated with hydrogen cyanide, so that a strict comparison could be made between the performances of the two fumigants. The rates of airing were also compared. The data demonstrate the grater suitability of methyl bromide for the fumigation of empty bags in barges.
South African fish products. Part XXI. Recovery of vitamin A in the unsaponifiable matter of fish liver oils
Authors: Black M. M. , Lamchen M. , Rapson W. S. , Schwartz H. M. , Van Rensburg N. J. 
Published: July 2007

AbstractThe percentage recovery of Vitamin A in the unsaponiflable matters from commercial South African hake, soupfin shark, dogfish, kabeljou and geelbek liver oils has been determined for a large number of samples and characteristic values for each type of oil have been established. Hake liver oils were exceptional in giving recoveries not significantly different from 100%, while recoveries from the other types of oils averaged from 93‐95%, and wore unaltered when the oils wore diluted with vegetable oils such as an employed in margarineo compositions. No explanation of the different recoveries if given, but possible causes are discussed.
The spontaneous combustion of hay. II. The composition of the acidity
Authors: Firth J. B. , Stuckey R. E. 
Published: July 2007

AbstractPrevious work by the authors showed that an acidity developed in hay which had undergone spontaneous combustion. Further examination of such hay indicated that the acidity was composed mainly of non‐volatile acids; this fraction contained lactic, malic, and succinic acids, while acotic and formic acids were present in the volatile acidity. Methods of analysis are given.
South African fish products. Part XXIII. Variations in the oil and vitamin A contents of the liver of the cape hake (Merluccius capensis, cast.)
Authors: Roux E. R. , Molteno C. J. 
Published: July 2007

AbstractFactory data collected at Cape Town and Port Elizabeth are used to demonstrate variations in the oil and vitamin A contents of the liver of the Cape hake. In addition to seasonal changes related to the sexual cycle, there are marked fluctuations from year to year, probably connected with variations in the food supply, which ultimately are related to oceanographic factors, such as sea temperatures, Migratory phenomena have an important bearing on the average size and physiological condition of the fish caught, and size of fish also markedly influences the oil and vitamin A content of the Users.
The nicotinic acid content of coffee
Authors: Hughes E. B. , Smith R. F. 
Published: July 2007

AbstractFrom 16 to 44 μg./g. of nicotinic acid were found in samples of raw coffee beans. Nicotinic acid in produced during the roasting of coffee by the decomposition of trigonelline present in the raw beans. The production of nicotinic acid is dependent on the extent of roasting, a dark roast coffee containing more than a light roast coffee. Normal samples of roasted coffee contained from 95 to 263 μg./g. of nicotinic acid. The nicotinic acid content of coffee is not dependent on the variety of bean. The nicotinic acid is almost completely extracted in the preparation of the beverage for drinking, the amount in a cup of white coffee (200 ml, half 10% coffee decoction and half milk) being between 1 and 2 mg. The pyridine in coffee also originates from the decomposition of trigonelline.
The determination of the moisture content of cereals by measurement of specific inductive capacity
Authors: Groves L. G. , King J. 
Published: July 2007

AbstractThe determination of the moisture content of a material by the measurement of its specific inductive capacity is now well established, and several commercial instruments are available using this principle, generally in conjunction with electrical conductivity. An instrument easily constructed in the laboratory is described in this paper, which it is hoped will enable the principle to be more widely used. The method employed in the determination of the moisture content of various cereals is described, together with the degree of accuracy to be expected and the limitations of the method.
The estimation of sulphur compounds in crude and refined benzoles. Part I
Authors: Claxton G. , Hoffert W. H. 
Published: July 2007

AbstractUntil recently the sulphur compounds in crude benzoles were generally considered to be chiefly carbon disulphide and thiophene, although the presence of other compounds such as sulphides, disulphides and mercaptans had been reported. With the exception of carbon disulphide, methods of estimation had not been accurately worked out and knowledge concerning the exact quantities of other sulphur compounds was scanty. Examination of a large number of crude benzoles in these laboratories had shown that normal high‐temperature benzoles contain approximately half their sulphur content as carbon disulphide. It has been customary to regard the remainder as thiophene and its derivatives, an assumption that is justified to some extent since other sulphur compounds, such as sulphides, behave in the same way as thiopheno during refining by sulphuric acid. For example, although a large number of makes and types of acid‐washed benzoic have been tested, it has always been found that the remaining sulphur, other than as carbon disulphide, was the same for a particular yield of benzole irrespective of the concentration and quantity of sulphuric acid used to obtain this yield.
The estimation of small quantities of total sulphur in benzoles
Authors: French K. H. V. , Claxton G. 
Published: July 2007

AbstractThe standard S.T.P.T.C* method of estimating total sulphur was designed primarily for determining sulphur in commercial products, in particular motor benzoic, of which tlio sulphur content is between 0·1 and 0·4% w/w. In connection with the estimation of individual sulphur compounds in benzolo a method is needed for quantities of sulphur of the order of 0·01% w/w. Such a method of analysis would also be, of extreme value for determining the sulphur in products such as pure benzole, now being required with low sulphur contents for synthetic processes.
Determination of the boiling‐points of liquids of low vapour pressure
Authors: Burrows G. 
Published: July 2007

AbstractA boiling‐point apparatus is described and an account is given of its use for determining the boiling‐points at reduced pressures of‐ various liquids of low vapour pressure. The theoretical relationship between temperature and vapour pressure is discussed and the vapour pressures of various liquids at room temperature are derived from the data obtained. Comparisons arc made with other published figures relating to the boiling‐points and vapour pressures of various liquids used in high‐vacuum technique.
Recent developments in the microbiology of retting. Part I.—the microbial flora in different systems of retting
Authors: Allen L. A. 
Published: July 2007

AbstractThe general bacterial flora was found to be similar in the different processes of flax‐retting investigated. Coliform bacteria, streptococci, and spore‐forming anaerobes consistently appeared in largo numbers. Continuous aeration of tbe rotting liquor with diffused air during the course of a ret encouraged the growth of aerobic and facultativo bacteria, but did not greatly ailed the number of anaerobes. Continuous circulation of retting liquor through n percolating filter removed a large proportion of bacteria from the liquor, but loft hirgoly undisturbed those growing in or near the flax straw.
The determination of the pyrethrins in pyrethrum concentrates in mineral oil
Authors: Martin I. T. , Brightwell S. T. P. 
Published: July 2007

AbstractA method is described for the determination of pyrethrin I in pyrethrum concentrates in light mid heavy mineral oils. The method is based that of Wileoxon as modified by Holaday and utilises the separation of chrysanthemum monocarboxylic acid and the reduction of Denier reagent. Modifications of the Wilcoxon‐Holaday method concerned with the initial removal of uncombined acids, the removal of the oil and the separation of the monocarboxylic acid have been introduced. The determination of the monocarboxylic acid by the reduction of Denier reagent gives results for pyrethrum I slightly in excess of those given by a modified Soil method involving separation of the monocarboxylic acid by steam distillation. pyrethrum II may be determined in oil solutions made from petroleum ether extracts of pyrethrum lowers by an application of the Soil method. Further work is required on the determination of pyrethrum II in oil solutions made from acctouo extracts of the flowers.
Insecticides: Chemical constitution and toxicity
Authors: Martin Hubert 
Published: July 2007

AbstractOf the several ways of studying the relationships between molecular structure and toxicity, the analytical method, when effects of modification and dissection of the molecule are followed, is applicable to insecticides of insignificant vapour pressure at ordinary temperatures. The effect of modification of the molecular structures of nicotine, rotenone, and of the pyrethrin‐synergists allied to sesamin on their insecticidal properties is discussed. The importance of physical properties affecting the distribution of the insecticide between the biophase in which it acts and the phase in which it is applied is illustrated by the case of the aliphatic thiocyanates. The reasons why DDT is insecticidal are discussed and it is shown that the possibility of ready dehydrochlorination is requisite for inseetieidaal properties in this series, an idea now extended to other chlorinated hydrocarbons.
Liquid‐vapour equilibrium data for the systems: Methyl methacry‐late‐methanol and methyl metha‐crylate‐methacrylic acid
Authors: Woods D. E. 
Published: July 2007

AbstractLiquid‐vapour equilibrium data for methyl methacrylate‐methanol and methyl methacrylate‐methacrylic acid mixtures have been determined using a modified Rosanoff apparatus at 200 mm. and 760 mm. Hg pressure. It has been found that methyl methaerylate forms constant‐boiling binary mixtures both with methanol and with water. Some physical properties of pure methyl methaerylate and mixtures with water, methanol and methacrylic acid have been determined.
An electrometric indicator to replace starch in iodine titrations of sulphurous acid in fruit juices
Authors: Ingram M. 
Published: July 2007

AbstractIt has been shown that a bright platinum electrode, used in conjunction with a very simple reference electrode and electrometer, is .an effective substitute for starch in iodometric titrations of fruit juices. The error in the determination of the end‐point by this means is some five times smaller than with starch, and end‐points un be observed equally well in highly coloured juices such as blackcurrant where starch cannot be used at all. The improvement in accuracy results partly from the greater sensitivity of the electrometric indicator, and partly because it gives a continuous indication of the approach of the end‐point so that delay in approaching the end‐point can be reduced to a minimum. In addition, factors of personal judgement are eliminated, and the determinations do not depend on the prevailing conditions of lighting.
Inhibition of catalysed thermal decomposition of DDT
Authors: Gunther Francis A. , Tow Lois R. 
Published: July 2007

AbstractIn the laboratory, picolinic acid and salicylal‐amino‐guanidine have been found to inhibit the iron catalysed thermal (110–120° for twenty‐four hours) decomposition of technical grade DDT very effectively at concentrations as low as 2% of the inhibitor. Under similar conditions the technical grade DDT decomposed (dehydro‐halogenated) quantitatively.
Starches and starch fractions. Part I. The determination of dextrose and maltose by the ferri‐cyanide‐carbonate reagent, with special reference to the effect of inorganic salts
Authors: Lampitt L. H. , Fuller C. H. F. , Goldenberc N. , Green G. H. 
Published: July 2007

AbstractThe oxidative power of the ferricyanide‐carbonate reagent towards dextrose and maltose is decreased by the presence of sodium chloride and sodium acetate, in quantities such as would be present after the hydrolysis of starch by hydrochloric acid or by β‐amylase in the presence of an acetic acid‐sodium acetate buffer. The oxidative power of the reagent is lowered by exposure to diffuse daylight and possibly also by prolonged storage in the dark.
The fractionation of binary mixtures in packed columns
Authors: Storrow J. Anderson , Willson B. D. 
Published: July 2007

AbstractThe dependence of the Height of B Transfer Unit upon the column operating characteristics and the physical properties of the mixtures distilled has been examined in experiments on two small packed columns in which carbon tetrachloride‐benzene and methyl‐cyclohexane‐toluene mixtures were distilled. Correlation of the experimental data by means of a dimensionless equation:– was not complete due to a vapour composition effect similar to that previously observed in experiments on wetted‐wall columns.
The preparation of hydrobromic acid by the reduction of bromine with sulphur
Authors: Bloch R. , Farkas L. , Goldschmiot P. , Littman H. Z. , Schachter O. 
Published: July 2007

AbstractThe reduction of bromine with sulphur to hydrobromic add in the presence of water can be carried out in one step above 70°. An aqueous solution containing about 45% of hydrobromic acid and 8% of sulphuric acid is obtained. The process is not only suitable for the preparation of hydrobromic acid in the laboratory, but has also been adapted to large‐scale industrial production. In this case, the dissipation of the heat of reaction was solved by using ice, instead of water, in a suitable apparatus.
Pectin studies. Part I. Method of purification
Authors: Lampitt L. H. , Money R. W. , Judge B. E. , Urie A. 
Published: July 2007

AbstractComparative rests were carried out on the purification of crude pectin extracts by (a) dialysis, (b) precipitation by alcohol, and (c) ionic exchange. The results showed that dialysis followed by precipitation gave the highest calcium pectate value and complete removal of sugars, free acids and free ash. Ionic exchange gave a pectin of considerably lower residual ash content, but the additional reduction was at the expense of the inorganic ions combined with the pectin and is thus of doubtful desirability, except for particular purposes.
Starches and starch fractions. Part III. The intensity of the colour of starch‐iodine‐iodide solutions as an index of the amylose‐amylo‐pectin ratio
Authors: Lampitt L. H. , Fuller C. H. F. , Goldenberg N. 
Published: July 2007

AbstractThe quantitative determination of the % of amylose and amylo‐pectin in starches and starch fractions is best carried out using a low starch: iodine ratio. The use of a high starch: iodine ratio is undesirable, since it may not reveal differences in the amylose : amylo‐pectin ratio, but, even under these unfavourable conditions, any significant differences in colour intensity are still indicative of differences in the amylose : amylopectin ratio.
Improved preparation of 2:4:6‐trinitrobenzoic acid
Authors: Brown D. J. 
Published: July 2007

AbstractThe preparation of 2 :4 : 6‐trinitrobenzoic acid by the oxidation of 2:4:6‐trinitrotoluene (TNT) in nitric acid solution with sodium chlorate, by the method of Lüttgen,1 has been rightly condemned by Clarke and Hartman2 on the grounds of control difficulty. However, it has been found that ‐with suitable modification this method produces trinitrobenzoic acid with the minimum of trouble and in 85—90% yield (cf. 60—70% by chromic acid oxidation).
Dextrins in flour and yeast raised bread
Authors: Cunliffe W. 
Published: July 2007

AbstractThe dextrin figure test originally devised by Kent‐Jones and Amos as an indication of possible trouble due to sticky numb in Irish soda bread has been studied in relation to yeast bread flou∼s. Observations are also rccorded on the effect of p∼ on the dextrin content of bread contaming excess barley malt a‐amylase in the presence of calcium arbonate.
Low frequency induction heating as applied to small scale chemical plant
Authors: Thacker G. O. , Hands C. H. G. 
Published: July 2007

AbstractThe principles of low frequency induction heating are briefly described and experiments on three small vessels arc recorded. Attention is drawn to the differences in behaviour of mild steel and cast iron. The data obtained are correlated with information given in the literature to assist in the design of other heaters. An example is given of a typical application.
Factors influencing the rate of nitration of 2:4 dinitrotoluene in a 2‐phase system
Authors: Bennett G. M. , Brand J. C. D. , Dine J. C. , Fysh D. , McClelland E. W. , James D. M. , Saunders T. C. , Wiseman L. A. , Williams Gwyn 
Published: July 2007

AbstractA study has been made of the two‐phase nitration of dinitrotoluene to trinitrotoluene in order to determine directly the influence of variations in the quantities and conditions on the rate of nitration. Small scale batch operations were made with standardized conditions and the extent of nitration found from the density of the product at 90°. The results arc discussed from the point of view of the authors' theory of nitration with mixed acids,' according to which the active nitrating agent is the NO2+ ion into which the nitric acid is converted by that portion of the sulphuric acid which is in molecular excess over the water present. Iris shown that potassium and nitrosyl bisulphates retard the reaction by pressing back the reversible formation of the NO2+ ion. Nitrous acid has a still larger inhibitory effect and its accumulation together with the water present muses not only a retardation, but sometimes the complete arrest of the reaction before the materials are exhausted.
The automatic control of the spectrographic exposure
Authors: Gentry C. H. R. , Newson D. , Rushman D. F. 
Published: July 2007

AbstractAn electronic circuit is described by which the following cycle of operations automatically occurs on initiation; the pre‐spark starts, the spectrograph shutter opens after a fixed time, the plate remains exposed for the required period, then the shutter closes just prior to switching off the spark and finally the apparatus is reset. By choosing suitable values of the components, a multi‐position selector switch enables a choice of pre‐spark and the exposure times to be made. It is claimed that this device eliminates some of the tedium of routine spectrograph analysis, saves the operator's time and eliminates some of the personal error.
A method of preparing guanidinium and substituted guanidinium salts
Authors: Macgregor J. H. 
Published: July 2007

AbstractThe preparation of guanidinium and substituted guanidinium salts is described. The method consists of boiling, in a suitable solvent, the corresponding alkali metal salt and an inorganic guanidinium salt, e.g., the hydrochloride or sulphate.
New analytical reactions with anionic and cationic wetting agents
Authors: Steigmann A. 
Published: July 2007

AbstractThe orthosilicates and metaphosphates of cetyltrimethyl‐ammonium bromide (“Cetavlon”)or of “Sapamine KW 200%,” absorb acid dyes and acid spot test reagents and therefore provide analytical “trace catchers.” “Cetavlon” also precipitates mercury, gold and platinum, or, rather, their anionic complexes (chloro‐aurates and platinates) from slightly acid or neutral solutions of the metal chlorides. Spot test papers with sapamine iodide are very selective for platinum and palladium and more sensitive than those with 2‐thiolbenziminazole. The oxidation of aromatic amines is greatly influenced by anionic wetting agents.
The determination of the surface area of powders by means of low‐temperature adsorption isotherms
Authors: Bugge P. E. , Kerlogue R. H. 
Published: July 2007

AbstractA simple routine procedure for the determination of the surface area of 'powders by means of low‐temperature adsorption isotherms is described with full experimental and and mathematical detail. A method of interpretation has been formulated permitting the elimination of the “deadspace” determination for routine procedure where the substance is known to give an S‐shaped isotherm.