bluuebunny/crossref_metadata_2025 huggingface dataset:
An electrometric indicator to replace starch in iodine titrations of sulphurous acid in fruit juices
Authors: Ingram M.
Published: July 2007

It 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

In 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

The 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

The 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

The 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

Comparative 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

The 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

The 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

The 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

The 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

A 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

An 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

The 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

The 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

A 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.
The ketonization of higher fatty acids with some observations on
Authors: Curtis R. G. , Dobson A. G. , Hatt H. H.
Published: July 2007

A number of metallic oxides and carbonates may be used as catalysts for the preparation of dialkyl ketones from higher fatty acids in the liquid phase. All cause violent frothing which can be controlled by adding the fatty acid gradually to the catalyst at the reaction temperature. The various metallic oxide and carbonate catalysts are compared and magnesium oxide is selected as most suited for the commercial preparation of ketones. The most suitable reaction temperature range is 330—360°. The crude ketone is greasy, but its properties arc greatly improved by pressing. During the reaction carbon dioxide is evolved in an amount equal to 94% of that required for complete ketonisation. Small amounts of carbon monoxide and other gases arc also formed. The progress of the reaction has been followed by measurement of the rate of liberation of carbon dioxide and the results arc shown to agree with the supposition that a keto‐acid arises as an intermediate in the formation of ketones. Interruption of the reaction and estimation of the unchanged acid present, together with a knowledge of the amount of carbon dioxide then liberated, allows the amount of keto‐acid present in the reaction mixture to be calculated. This is found to be constant during the early stages of the reaction, but increases greatly when the reaction becomes violent. It is suggested that formation of the salt of the keto‐acid is the rate‐determining reaction and that this reaction is catalysed by the metallic oxide used.
The preparation of mixed benzyl pyridine isomers on a pilot plant scale
Authors: Hands C. H. G. , Whitt F. R.
Published: July 2007

A semi‐technical method of preparing a mixture of 2 and 4‐benzyl pyridines at the rate of several cwt. per week utilizing the reaction between benzyl chloride and pyridine is described Satisfactory control of the reaction on the 1 cwt. batch size was obtained by the use of circulating hot oil as the reaction vessel heating medium.
A simple method for the preparation of hydrobromic acid
Authors: Goldschmidt F. , Dishon B. R.
Published: July 2007

The reaction of one g.‐atom sulphur, six g.‐atoms bromine and an excess of water has been studied. The reaction takes place in at least two steps, the first being the formation of sulphur mono‐bromide, the second the reaction of this compound with bromine and water. The reaction results in the formation of hydrobromic acid and sulphuric acid. Hydrobromic acid has a retarding influence on the formation of sulphur monobromide but accelerates the reaction of sulphur monobromide with bromine and water. A method for the preparation of hydrobromic acid was worked out based on these observations.
The methylation of meso‐inositol
Authors: McGowan J. C.
Published: July 2007

meso‐Inositol hexamethyl ether and the acetate of a meso‐inesitol pentamethyl ether have been prepared. These compounds show much less insecticidal activity than “Gammexane” (γ‐1,2,3,4,5,6‐hexachlorocydohexane) to which they arc probably structurally related.
Stoichiometric extraction of mixed acids
Authors: Brancker A. V.
Published: July 2007

The separation of the components of a mixture of acids, the dissociation constants of which exhibit small differences, is a problem of some difficulty. In those cases such as penicillin acids which arc soluble in water and a water immiscible solvent, a mixture of acids is extracted from the aqueous phase, and re‐extracted from the resultant solvent medium by alkali, to give an aqueous solution of alkali salts of a mixture of acids. In the process of determining the pH of the aqueous phase during the re‐extraction with alkali of penicillin acids from the solvent phase, 7 inflexion points were observed in the titration curve corresponding to 7 possible acids and, on the basis of this observation, a method was evolved for the separation of these acids by successive additions of alkali in amounts approximately stoichiometrically equivalent to the quantities of acids present. To make the method of general applicability a case of 4 mixed acids has been theoretically investigated, wherein the titration curve, calculated for the solvent‐aqueous alkali system, shows 4 distinct points of inflexion which would permit of the separation of 4 such acids by stoichiometric extraction.
An apparatus for the detection and estimation of small amounts of chloride
Authors: Scott B. A.
Published: July 2007

An apparatus for the detection and estimation of low concentrations of chloride by means of a cell‐comprising silver chloride and lead sulphate electrodes is described. The method is quick and convenient and the accuracy is of the order of ± 10% down to 1 p.p.m. or less. It is particularly suitable for the determination of small amounts of chloride in boiler water since other anions commonly present do not interfere.
The action of natural waters on lead
Authors: Miles G.
Published: July 2007

The analyses of a series of natural waters are given, together with the results of a standard test for initial action on lead. Correlation between the calcium carbonate saturation index, the organic content and the degree of initial action on lead of these waters is attempted.
The reaction of sulphur and sulphur compounds with olefinic substances. Part V. Rubber vulcanization
Authors: Bloomfield G. F.
Published: July 2007

Data presented for a range of vulcanized rubbers prepared under different conditions show that while olefinic unsaturation becomes reduced by vulcanization in the proportion of one double bond for each sulphur atom combined with a C5H‐unit, the original H/C ratio of 8/5 is not altered. The loss of unsaturation is somewhat modified when zinc oxide or certain accelerators are also present. Oxygen has a slight inhibiting effect on vulcanization; hydrogen sulphide and mercaptans markedly catalyse the vulcanization reaction without, apparently, affecting the efficiency of the sulphur cross‐linking reaction.

In confirmation of the results of Hull, Olsen, and France1, a small proportion of zinc oxide or a soluble zinc soap promotes a reaction between sulphur and mercapto groups whereby di‐ and poly‐sulphides arc formed with liberation of hydrogen sulphide. The same type of activity is shown by some of the nitrogenous accelerators commonly used in rubber vulcanization. Substantial conversion of mercapto groups into polysulphidc linkages is therefore to be expected when vulcanization is conducted in the presence of these auxiliary substances.
Experiments on the corrosion resistance of porous bronze compacts produced by powder metallurgy
Authors: Hallett M. M.
Published: July 2007

Tests have been made on the corrosion resistance of porous bronze compacts, produced by powder metallurgy, to a range of acids, alkalis, and salts, under aerated conditions, and in some cases under stagnant conditions, in comparison with the resistance of solid bronze under the same conditions. The corrosion resistance of the two types of material did not differ greatly in many cases, but in caustic soda and in concentrated sulphuric acid, major differences appeared, which were studied in greater detail.
The partition of hydrogen chloride between water and benzene
Authors: Such J. E. , Tomlinson R. H.
Published: July 2007

A simple partition method using benzene has been found of practical value in determining the partial vapour pressure of HC1 over aqueous solutions containing also a second solute, the latter being insoluble in benzene, in regions of composition corresponding to the maximum concentration of HC1 in effluent gases permitted by factory regulations. The partition of hydrogen chloride between. water and benzene has been measured at 30° over a wide range of concentrations and over a lesser range at 40°. The data are correlated with other known partition data for this system and with published measurements of hydrogen chloride gas phase concentrations over benzene solutions at 20, 25, 30 and 40°. Over the molality range 7·2 × 10‐6 to 2·73 × 10‐1in benzene, the activity coefficient of hydrogen chloride in benzene has been shown to be unity, and to be unaffected by the presence of the water also in partition equilibrium. It is shown to be a theoretical possibility that combination of HCl with H2O in the benzene might cause the ratio of molality of HCl in benzene (M′t) to activity of HCl in water (aHCl) to increase at dilutions greater than those investigated. The temperature dependence of the partition constant is represented over the temperature range 20‐40° by the equation The difference of partial molar heat content of HCl in the two solvents at infinite dilution calculated from the equation is 13, 600 calorics per g. mol. Correspondingly the heat of solution of gaseous HCl in benzene at infinite dilution is 4660 calories per g. mol.
The prevention of dust explosions caused by high explosive bombs in flour mills
Authors: Burgoyne J. H. , Rasbash D. J.
Published: July 2007

The heavy loss of flour mills under enemy attack from the air was shown to be largely attributable to extensive fires resulting from dust explosions initiated by high‐explosive bombs, and a scheme of protection was worked out by Professor G. I. Finch in the capacity of Scientific Adviser to the Fire Research Division of the Research and Experiments Department, Ministry of Home Security. According to this scheme, propagation of the secondary dust explosion was to be prevented by packets of incombustible dust so placed in the mill buildings as to be broken open, and their contents dispersed by the high‐explosive simultaneously with the liberation of combustible dust (flour, etc.) from damaged plant. Refinements to the original scheme were made as a result of the experimental work described.

Flame propagation tests showed that a mixture of 90% powdered limestone with 10% sodium bicarbonate would be a suitable incombustible dust for the purpose; the small addition of bicarbonate greatly enhancing the 'flame‐suppressing power of the mineral dust. Investigations into the agglomerating, caking and segregating characteristics of this and related mixtures, mainly in relation to mixture composition and particle size, were carried out, and indications are given of the way in which these factors may be adjusted to give the best all‐round specification for the mixture. An experimental installation in a flour mill is described.
Synthesis of benzaldehyde, a possible route to toluene
Authors: Hardy D. V. N.
Published: July 2007

The synthesis of benzaldehyde from benzene and carbon monoxide under pressure has been examined with a view its use for the production of toluene. With reference to the aluminium chloride used, the yield of benzaldehyde may reach 85%, but it was found impossible to recover the chloride. Attempts to find an alternative catalyst were unsuccessful. The factors governing the synthesis have been studied and it has been shown that the rate of reaction may be accelerated by adding not only benzaldehyde but also furfural and diethyl ether. The reaction is also accelerated by hydrogen chloride and by small amounts of water, but use of the latter leads to a smaller yield. The mechanism of the reaction is discussed.
Methods for the routine estimation of mannitol, alginic acid, and combined fucose in seaweeds
Authors: Cameron M. C. , Ross A. G. , Percival E. G. V.
Published: July 2007

Methods are described for the routine estimation in ground seaweed samples of mannitol by periodate oxidation, of alginic acid by isolation and the displacement of acetic acid from calcium acetate, of laminarin by hydrolysis to glucose and its estimation with the Shaffer‐Somogyi reagent, and of fucose (after hydrolysis) by periodatc oxidation and estimation of the liberated acetaldehyde.
Correction for gamma changes due to variations in exposure and development with reference to spectrographs analysis (two line‐pair method)
Authors: Sanders C.
Published: July 2007

The procedure to be described has been found to be useful in the spectrographs determination of composition by the method in which the log, ratio of deflection is plotted against % content (or log. % content), no intensity calibration being carried out. Essentially the procedure consists of using two line pairs for each determination, one on the positive and the other on the negative side of log. ratio 0·000 Where the log. ratio is reasonably near zero it is, of course, unnecessary to read two line pairs. By placing a straight edge through the log. ratio points on the corresponding composition curves and reading off the composition corresponding to the log. ratio 0·000 on this straight line a weighted average is obtained which corrects for plate response, thus giving a better accuracy than that obtained by the use of individual line pairs and log. ratios uncorrected for intensity by plate characteristic curve technique.
A phototurbidimetric method for the estimation of so3 in the presence of so2
Authors: Corbett P. F.
Published: July 2007

The factors influencing the turbidimetric estimation of sulphur dioxide in the presence of sulphur dioxide have been investigated, and a procedure is recommended for using the method in the analysis of boiler plant flue gases.
The catalytic ethylation of benzene with ethanol in the gaseous phase
Authors: Cullinane N. M. , Chard S. J. , Meatyard R.
Published: July 2007

Mixtures in varying proportions of benzene and ethyl alcohol were led over catalysts of the alumina‐silica and alumina type at different temperatures. The best yields of ethylbenzene (about 25%, based on the tenzene consumed) were obtained with the former catalysts, the optimum temperature being) 350°.

Ethylbenzene is an important intermediate for the production of styrene, which is widely used for conversion into synthetic rubber and resins. Recently a large number of catalytic methods for the ethylation of benzene have been published, especially in the U.S.A.
Contribution to the direct synthesis of phenylochlrosilanes
Authors: Riccoboni L. , Zotta M.
Published: July 2007

The preparation of alkyl‐ or aryl‐chlorosilanes, extensively studied during the last forty years, is carried out mostly by allowing SiCl4 to act cither on Grignard reagents1 or on alkyl‐zinc or mercury‐compounds.2 The. Fittig‐Wurtz method for the preparation of tetra‐substituted deri‐vates was first utilized by Polis3 and later by Kipping and Lloyd.4 Schumb, Akermann and Saffer found it practical to preparathe sodium organic derivative separately and then to treat‐it with the silicon halide. The action of Grignard reagents on ethyl silicate has been studied particularly by Russian chemists5.
A method for the determination of the apparent density of dry powders
Authors: Ault W. B.
Published: July 2007

A description is given of a method of determining the apparent density of dry powders which has proved of great use over a period of 45 years. While it was originally developed for precipitated calcium carbonate it can be applied to powders generally. It has been used to distinguish between various grades of powder and its repeatability is good for this class of test as long as specified precautions arc taken.
The corrosion of metals in atmospheres containing sulphur dioxide. Part I
Authors: Tolley G.
Published: July 2007

Results are presented for the corrosion of mild steel, aluminium sprayed and aluminized steel by air containing from 2%‐6% SO2, at temperatures of 300°‐700°. The influence of gas velocity, temperature, and concentration of SO2 has been found. Corrosion time curves up to 40 hours' exposure are given for 0.2% and 4% SO2‐air mixtures at 600°. Small concentrations of water vapour in the gas decrease corrosion of mild steel, but further additions increase corrosion. The results show that the catalytic formation of sulphur trioxide on the surface of the metals is of great importance in determining the rate of corrosion.
The action of metals of benzaldehyde
Authors: Whitt F. R.
Published: July 2007

The resuls of experiments involving the refluxing of benzaldehyde with powdered zinc or iron showed that various reactions took place to produce phyenyl group containing compounds of less oxygen content than benzaldehyde.
Microbiological problems in the manufacture of sugar from beet. II. Losses due to fermentation during the diffusion process
Authors: Allen L. A. , Cooper A. H. , Maxwell M. C. C.
Published: July 2007

During the process of diffusion the gas which collects at the top of a diffuser contains a decreasing proportion of carbon dioxide and an increasing proportion of hydorgen. Observations on the respiration of sliced beet suggest that this factor may be largerly responsible for carbon dioxide which appears at the beginning of diffusion, but that the rising remperature in the3 battery soon inhibits further plant respiration. Periodic opening of the release cocks, which occurs during operation of the battery, then trends to replace the gases originally present by those released from the juice. These include the products of fermentation, which consist of carbon dioxide and hydrogen.

The thermophilic bacterial flora of the diffusing juice consist maninly of lactobacilli and gas ‐forming anaerobes. These appear to be largely responbible for production of gas, formation of invert sugar, and the appearance in the juiice of small quantities of lactic, butyric, and acetic acids. The temperature relations of the strains of these organisms tested in the laboratory suggest that their activities would be inhibited if the temperature of the battery were consistently maintained above 70°
The insoluble matter of coal tar. V. Coal tar resins
Authors: Green S. J. , Mukherji S. M.
Published: July 2007

Further work on resinenes is reported including hydrolysis, bromination, thermal decomposition, dehydrogenation, hydrogenation, and alk line permanganate oxidation. The resinenes give neutral and phenolic products on hydrolysis. Dehydrogenation with selenium gives neutral and phenolic products. Oxidation gives a benzenoid residue including benzene hexacarboxylic acid in addition to more complex water soluble acids. The significance of these results is discussed.
An improved method for the generation of insecticidal smokes
Authors: Heath C. D.
Published: July 2007

The development of an improved pyrotechnic composition for the generation of insecticidal smokes is described. This composition has the advantage over previous compositions that it will burn without flame when placed loosely in an open tin. At the same time, the efficiency of the composition, about 90%, is as high as can be expected for this method of generating smokes.
Chromatography in an explosives laboratory
Authors: Ovenston T. C. J.
Published: July 2007

This paper describes some of the features of the Tswett chromatographic technique suited for application to the examination and study of propellants and high explosives. Particular reference is made to an adsorbent consisting of fine silica gel admixed with a filter and. Adsorption series are given for some high explosives and propellant ingredients and characteristic streak tests are described. Finally, a survey is made of a variety of chromatographic applications to problems ranging from analysis and age assessement of propellants to investigations into the causes of the occasional unforeseen colouring of freshly manufactured fishless cordite.
Drying of granulated materials. Part I. Drying of a single granule
Authors: Van Krevelen D. W. , Hoftijzer P. J.
Published: July 2007

Granules of wet marl, suspended from the beam of a torsion balance, were dried in a current of dry air. Two rate periods were observed; during the first the rate of drying remains constant, during the second it decreases. With the aid of the conception of Ceaglske and Hougen on moisture distribution in granular materials equations for the rate of drying during the second stage could be derived which arc proved to be in agreement with the experiments. Besides these theoretical equations dimensionless empirical expressions were derived for the two drying stages which enable the rate of drying of single granules under arbitrary conditions to be calculated.

Granules of nitrochalk fertilizer, when dried in the same apparatus, showed quite a different behaviour. At first the rate of drying decreased rapidly and soon reached a constant value. This constant rate was over a thousand times smaller than the rate of drying in the case where mass transfer through the gas film is rate determining. The rapid decrease of the drying me at the start could be ascribed to n filling of the pores by solid ammonium nitrate. As soon as the rate became constant drying took place exclusively by diffusion of water vapour through a thin crystal film which had an average thickness of 10‐3 to 10‐5 cm. In this period the rate of drying was only influenced by temperature and by size and structure of the granule.
The waterproofing of soil by resinous materials
Authors: Clare K. E.
Published: July 2007

The stability of cohesive soils is determined largely by their moisture content, and methods of waterproofing or “stabilizing” soils have an important application in the field of road construction. This paper describes study made at the Road Research Laboratory of a method of waterproofing such soils by the addition of small quantities of two natural resinous match, “Vinsol” resin and rosin. The study consisted of an investigation of the properties of soil containing resin, and of the mechanism whereby the waterproofing action is obtained. It was found that a maximum waterproofing effect is obtained with concentrations of resin of the order of I% by weight of the soil, that the effect may take some time to develop, and that the presence of resin affects the compaction properties of the soil. The waterproofing obtained is only operative when the soil has an acidic reaction, but it is shown that a resinous emulsion can be used to waterproof chalky soil. The Kozeny equation for the rate of capillary absorption of water by soil has been used in assessing the reduction in the rate of absorption caused by the addition of “Vinsol” resin to soil. It is considered improbable that the addition of resin reduces the rate of absorption, either by blocking the major soil pores, or by adsorption on the surfaces of the soil particles. It is shown that a reduction in surface tension, as measured by the force exerted on a stirrup dipping into water, is also not a determining factor. It is considered that the most probable mechanism is one in which molecular films of resin spread out at the air water interfaces in the moist soil. These films resist the entrance of further water owing to the tendency to reduce the total area of the interface, and the compressive strength of the film becomes the determining factor once the film is spread, by reducing the effective surface tension of the soil water. Pressure/ area relationships for films of the resinous materials investigated are presented, showing that the reduction in surface tension obtained due to the compressive strength of the films is of the required order.
A furnace for use in combustion studies
Authors: Chamberlain G. H. N.
Published: July 2007

The furnace described below, is one which has given satisfactory service, during the past two years, in studies on the vapour phase oxidation of ethers and hydrocarbons, the results of which have been published elsewhere.
Drying of granulated materials. Part II. Drying of granules in rotary driers
Authors: Van Krevelen D. W. , Hofitjzer P. J.
Published: July 2007

The product of residence time (t), number of revolutions of the dryer per unit of time (n), ratio of diameter to length of the dryer.

(d/l) and the tangent of the angle of inclination (tan α) appears to be constant for every dryer; given by: tnd tan α/l.

The constant c depends on the construction of the dryer and is nearly inversely proportional to the number of steps into which die diameter of the dryer is divided by the lifter construction. The drying rate of granules which contain no soluble salts in a rotary dryer is smaller than in freely suspended state at the same Reynolds number of flow.

The ratio qudrying rate in a torary dryer/drying rate of freely suspended granules increases.

With the number of revolutions. n. Approximately. q = 1/4 to 1/5 when n = 10 r.p.m. and q ∼ n0.5. The experiments do nit allow quantitative conclusions to be drawn on the rate of drying in the second period. The rate of drying of nitrochalk granules in a rotary dryer proved to be the same as for freely suspended granules at the same temperature.
Application of fumigants to ships and warehouses. VII. Fumigation of dried fruit with methyl bromide in chambers
Authors: Page A. B. P. , Lubatti O. F.
Published: July 2007

These are the second and third series of experiments designed to provide safe and efficient fumigation of dried fruit with methyl bromide. Loss due to leakage and absorption in the fabric of the chamber is reduced if bituminous felt sides arc replaced by brick walls surfaced with fine sand and cement and a waterproofing agent. Distribution is uniform with close stacking when an efficient method of circulation is used. With forced circulation air‐tightness of the chamber is essential. Under the conditions described, one hour's airing is sufficient to permit unloading.
The production of 96% sulphuric acid on a chamber plant
Authors: Cormack S. B. , Stubbs L.
Published: July 2007

In this paper an account is given of a tower on a chamber acid plant which has been designed and operated in order to produce 96% sulphuric acid. So far as the authors are aware, no such tower has been reported in the literature and it may well be that the one now‐described is unique. In any event the design and operation of such a tower demonstrates a method of employing this section of a chamber plant in order to obtain a very high efficiency of heat utilization and to give a grade of sulphuric acid which it has hitherto been considered only possible to supply from contact plants or by independent concentration units. It was felt that some details of this work would be of particular interest to those associated with industrial and engineering chemistry, and it is especially appropriate that the first general publication of this information should be to the Society Of Chemical Industry in Glasgow, since the tower to be described was built and operated at St. Rollox Works, Glasgow.

It may be recalled at this stage, that the early plants for the production of sulphuric acid from sulphur dioxide, oxygen and water in the presence of nitrous gases consisted simply of chambers into which trays of burning sulphur and saltpetre were pushed. The first great improvement was the introduction of the Gay Lussac tower to absorb the nitrous gases in sulphuric acid, but the nitrous gases were recovered from the sulphuric acid and the acid was concentrated in a system independent of the chamber plant, until Glover introduced a tower at the front of the chambers to recover the “nitre” from the Gay Lussac tower acid and to concentrate a mixture of the “nitrous vitriol” so obtained and the acid from the chambers. It always seems, however, to have been generally considered undesirable, and certainly very difficult, to concentrate the acid to much more than 150° Tw. (82%) in the Glover tower, although it was recognized that additional heat was available by the attempts which were made to operate concentrating pans on top of the pyrites and brimstone burners.
The practical problems of corrosion. Part XII. The influence of corrosion on the thermal deposition of calcium carbonate
Authors: Wanklyn J. N. , Evans U. R.
Published: July 2007

Steel specimens partly immersed in calcium bicarbonate solution develop a white band of calcium carbonate, the cathodic product, along the water‐line. When subsequently the surface is more deeply immersed in fresh bicarbonate solution, and heat conveyed to the liquid through the steel, the distribution of the calcium carbonate thrown out by thermal decomposition is almost unrelated to that of the calcium carbonate produced in the previous corrosion stage. Under the experimental conditions, the corrosion product contained both calcite and aragonite, and the thermal deposit only aragonite.
The effect of ventilation in moisture testing ovens
Authors: Iles W. G. , Sharman C. F.
Published: July 2007

During a study of the effect of ventilation rate on the loss of weight obtained in a standard moisture testing oven, apparently anomalous results have brought to light a “steaming effect” which can seriously vitiate moisture determinations upon biological material if ventilation with dry air is inadequate. Reference is made to an industrial oven developed as a result of this work.
A convenient method for storing and dispensing purified sodium
Authors: Dostrovskv I. , Llewellyn D. H.
Published: July 2007

A convenient method of storing and dispensing purified sodium is described which is particularly suitable for adding sodium to samples of isotopically enriched water, and for the preparation of carbonate‐free alkaline solutions in water and alcohol.
The practical, problems of corrosion. Part XIII. The painting of wet steel surfaces
Authors: Mayne J. E. O. , Evans U. R.
Published: July 2007

In 1936, Britton and one of the authors,1 in a review of the outdoor exposure rests organized from Cambridge, expressed the view that “An invisible film of condensed moisture is prejudicial to nearly all types of paints; therefore painting should not be commenced too early in the day.” In an earlier statement,2 reference was made to the danger of “extra moisture entrapped when the painting was early.” On the other hand, certain other experiments had suggested that, when paint was applied to a steel surface carrying large visible drops of water, the water was generally not entrapped below the coat, hut was either expelled or emulsified; indeed, when a deliberate attempt was made to shut in water below paint, it was found difficult to do this, except at re‐entrant angles.

In 1940, fresh experiments were started, designed (I) to compare the behaviour of paint‐coats applied to deliberately wetted surfaces with that of similar coats applied to dry steel, and (2) to ascertain whether any troubles encountered in painting wet steel could be overcome by use of emulsion paints‐‐‐such as were being developed about that time in the laboratory.
The mercuric chloride catalysed condensation of arsenious chloride with acetylene
Authors: Jones W. E. , Rosser R. J. , Woodward F. N.
Published: July 2007

Lewisite I, relatively free from lewisites II and III, is readily obtained by passing acetylence into a mixture of arsenious chloride and a solution of mercuric chloride in either 18% hydrochloric acid or saturated sodium 'chloride solution. In the latter case, the arsenious chloride is diluted with carbon terrachloride. Under optimum conditions the yield is 80‐85% calculated on the arsenious chloride consumed. In both cases β‐chlorovinylmercuric chloride m.p. 129°, is an intermediate and this is most readily obtained by passing acetylene into a solution of mercuric chloride in aqucous sodium chloride containing a little hydrochloric acid.
High efficiency laboratory fractionation. III. A small analytical
Authors: Dixon O. G.
Published: July 2007

A small still, made from heat‐resisting glass, for the fractionation of about 20 ml. of liquid, is described.

It comprises a fractionating column 6 in. long and I in. bore packed with in. gauze rings and sealed to a boiler which is fined wih an external resistance heater. The column, when tested ushg a mixture of normal heptane‐methyl Eyclohcxanc, has a performance equivatent to about 12 theoretical plates at a vaspour veiocity of 0.8 ft. per second, the dynamic liquid hold‐up is approximately I ml. and the static hold‐up is 0.1 ml. The sull may be used at atmospheric pressure to fractionate material boiling up. to 250°c. and, because of the low pressure drop, it is very suitable also for fractionation at reduced pressure.
The laboratory preparation of p‐aminosalicylic acid from phenyl‐acetic acid
Authors: McGhie J. F. , Morton C. , Reynolds B. L. , Spence J. W.
Published: July 2007

In the course of related preparative work on p‐aminosalicylic acid derivatives, it was brought to our notice by certain workers on the bacteriological side that samples of the acid itself, obtained by them from different sources and used by them, did not always appear to be uniform, either physically, or in their in vitro bacteriology. It was decided therefore to explore the possibilities of a convenient laboratory synthesis which would yield consistent p‐aminosalicylic acid in working quantities, and involve only ordinary bench equipment.
Physics of the low‐temperature vacuum drying process. Part I
Authors: Ede A. J.
Published: July 2007

An account is given of some of the more purely physical aspects of the process of drying sensitive materials in vacuo at a low temperature. A relation is established on theoretical and experimental grounds, between the mean air pressure in the desiccator, the rate of drying, and the difference between the vapour pressures at the evaporator and condenser. Considerations arising from the shape and size of the desiccator, evaporator and condenser ate discussed.

The process whereby sensitive materials are dried in the frozen state in a moderately high vacuum is now well established and has been used on a commercial scale for the preparation of dried blood plasma and penicillin.1,2,3,4 In view of its high cost it has not been applied to foodstuffs to any considerable extent, although the results are in most cases superior to those of any other method of drying, and rival those of quick‐freezing.5,6,7 However, good results have been obtained with foodstuffs at higher temperatures and pressures than those usually considered necessary; this paper describes some experiments and observations on the process under such conditions which are independent of the material being dried; a second paper will describe the results obtained with green peas.

The process, as it will be considered here, consists essentially in the sublimation of the ice contained in the frozen material (the “evaporator”) and its condensation as a layer of ice upon a cold surface (the “condenser”); it takes place in a vessel known as the “desiccator,”, the pressure in which is wry considerably reduced. The rate of drying is controlled almost entirely by the rate at which the evaporator is heated, since apart from losses due to radiation and conduction, which arc very small until the concluding stage is reached, all the heat applied must be used as latent heat of sublimation.

In order that the final product shall be of satisfactory quality, an upper limit must be fixed to the temperature of the material at each stage of the process. Since the principal factor influencing the temperature of the evaporator is the vapour pressure around it, one requirement of a satisfactory plant is that the desired rate of drying may take place with a sufficiently low vapour pressure at the evaporator.
The essential oil of Pittosporum tenuifolium
Authors: Calder A. J. , Carter C. I.
Published: July 2007

The Pittosporaceae is one of the smaller plant families and the typical genus Pittosporum includes most of the species, some seventy of which arc distributed in New Zealand, Australia, East Indies and Asia. It has been reported that various species of this genus have aromatic odours due to the essential oils they contain, bur apparently there is published information concerning only four of them, P. resiniferum,1 P. eugeniodes,2 P. undulatum,3 and P. Pentandrum.4 The essential oils of the first two contain n‐heptane and n‐nonane respectively, the her to the extent of 60%. It seemed of interest to ascertain whether the oils of this genus might be divided into two classes, one giving normal plant constituents and the other features by the presence of paraffins and hydrogenated terpenes. To this end, a comparison of the New Zealand species is being undertaken and the oil of P. renuifolium is the second to be chemically examined.
African drying oils. IV. Component sunflower seed oil. acids of some linoleic‐rich oils
Authors: Barker C. , Crossley A. , Hilditch T. P.
Published: July 2007

The fatty oils from ten specimens of African sunflower seed from widely different areas, and an Argentine sunflower seed oil have been studied. The iodine values of the oils raged from 113–136, their linoleic acid contents from 44% to 72% and their oleic acid contents from 43% to 14%. Sunflower seed oils in which linoleic acid forms about 70% or more of the total fatty acids are excellent non‐yellowing drying oils. Although the results reported in this paper are insufficient to define whether the wide variations in the proportions of linoleic and oleic acids arc due to environmental or varietal causes, there is reason to consider that the environment of the sunflower plant exerts a much greater influence on the composition of the oil than differences in the variety of seed grown.
The technical preparation of dimidium bromide: A new phenanthridine synthesis
Authors: Barber H. J. , Bretherick L. , Eldridge E. M. , Holt S. J. , Wragg W. R.
Published: July 2007

In the course of process development for the trypanocidal drug dimidium bromide, a study has been made of the Morgan‐Walls phosphoryl chloride cyclintion of 4:4′‐dinitro‐z‐bewmidodi‐phenyl to the corresponding pheananthridine. The reaction involves the readily isolated intermediate iminochloride which undergoes facile cyclization only in presence of certain inorganic halide catalysts. The analogy to the Friedel‐Crafts reaction is discussed.

A novel synthesis of the same phenanthridine by direct interaction of 4 :4′‐dinitro‐2‐aminodiphenyl and benzotrichloride is reported. This reaction entails the intermediate formation successively of an amidine and the iminochloride, and also requires catalysis by metal halides. It has been developed to a much simplified process giving excellent over‐all yields.

A new type of derivative of dimidium is also described. This is 2: 7‐diamino‐9‐butoxy‐9‐phenyl‐10‐methyl‐9:10‐dihydrophenanthridine (‘butoxide’); it is valuable in the preparation of dimidium salts.