摘要:

AbstractA method is described for the determination of the rate at which compounds of the toxic metals, copper and mercury, leach into sea water from anti‐fouling compositions. The method is suitable for stations where sea water is not directly accessible. Colorimetric procedures for the determination of copper and mercury in sea water arc described, and such aspects as the state in which the toxic metals arc dissolved, and the stability of the leachates, are dealt with. The practical implications of the functioning of anti‐fouling compositions, and the maintenance of a sufficiently high leaching rate arc discussed, special reference being made to the work of U.S. investigators at the Woods Hole Marine Biological Laborator

ISSN:0368-4075    

DOI:10.1002/jctb.5000651101

出版商:John Wiley&Sons, Ltd    

年代:1946

数据来源: WILEY

摘要:

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 yi

ISSN:0368-4075    

DOI:10.1002/jctb.5000651102

出版商:John Wiley&Sons, Ltd    

年代:1946

数据来源: WILEY

摘要:

AbstractBased on the experiments described in Part I, methods of analysis of sulphur compounds that have been found successful are described in detail, followed by a scheme of analysis for a complete examination of the sulphur compounds in a crude or refined benzole. For the sake of convenience, the methods of analysis are given in the order in which they appear in the complete scheme.

ISSN:0368-4075    

DOI:10.1002/jctb.5000651103

出版商:John Wiley&Sons, Ltd    

年代:1946

数据来源: WILEY

摘要:

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 process

ISSN:0368-4075    

DOI:10.1002/jctb.5000651104

出版商:John Wiley&Sons, Ltd    

年代:1946

数据来源: WILEY

摘要:

AbstractThe work described in this paper for rendering marine waters potable was undertaken early in 11/42. Sea water contains approximately 35 grams per litre of total solids, the chief Halts being sodium chloride, magnesium chloride, magnesium sulphate and potassium sulphate. This high eon‐cent rat ion of salts causes the water to be undrinkable, for the water cannot pass from the solution through the semi‐permeable membranes into the bloodstream, where the concentration of sodium chloride is only between 7 to 8 grains per li

ISSN:0368-4075    

DOI:10.1002/jctb.5000651105

出版商:John Wiley&Sons, Ltd    

年代:1946

数据来源: WILEY

摘要:

AbstractIn an attempt to use the equipment available for the determination of the exchangeable cations in soils, u statistical analysis has been made of the errors in the spectrochemical results obtained by means of an air‐acetylene flame and a large quartz, spectrograph. Even with an elementary technique, an average standard error of less than 4% was obtained. Factors contributing to the total error, such as the error of a microphotometer reading, fluctuations of the flame, and variations of the photographic emulsion, have been studied; two types of plate, sensitised and non‐sensitised, have been examined, It has been shown that most of the total error was due to variations in the photographic plates, and the significance of this in relation to the placement of the standard spectrograms on a plate is discussed. It has been found that, in general, a large quartz spectrograph is not suitable for use with an air‐acetylene Hume because the very low light‐collecting power of the instrument necessitates very long exposures or the use of solutions of impracticably high concentrations, or sometim

ISSN:0368-4075    

DOI:10.1002/jctb.5000651106

出版商:John Wiley&Sons, Ltd    

年代:1946

数据来源: WILEY

摘要:

AbstractThe thermal decomposition of pure D.D.T. at various temperatures has been examined by direct measurement of the hydrogen chloride evolved in the reaction. The evolution of gas is only very slight at the melting point of the compound, but it is rapid in the neighbourhood of 200°. Expressions are given for calculating the amount of gas evolved under these conditions. The phase equilibria of D.D.T. with 1: 1‐dichloro‐2:2‐di‐(4‐chlorophenyl) ethylene, naphthalene and 4 :4′‐diehlorobenzo‐phenone respectively, have been examined. The influence of D.D.T. on the miseibility of phenol and water has also been investigated, and it is shown that the substance can be estimated by measuring the rise in the critical solu

ISSN:0368-4075    

DOI:10.1002/jctb.5000651107

出版商:John Wiley&Sons, Ltd    

年代:1946

数据来源: WILEY

摘要:

AbstractThe insecticidal powers of forty‐one compounds analogous to DDT (αα‐bis‐(γ‐chlorphenyl)‐βββ‐trichlorethane) have been examined by tests with human lice and bed bugs. Wherever possible, the substances were dissolved in refined mineral oil and sprayed directly at the insects. Compounds insoluble in oil were tested as dry powders or aqueous solutions. Some of the compounds examined showed insectieidal powers of the same type as DDT, the most toxic compounds being those whoso molecules most resembled DDT. All the effective compounds were to some extent oil‐soluble but only a small degree of this property appears to be essential. Two theories concerning the mode of action of DDT are discussed but they do not receive support fr

ISSN:0368-4075    

DOI:10.1002/jctb.5000651108

出版商:John Wiley&Sons, Ltd    

年代:1946

数据来源: WILEY

摘要:

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

ISSN:0368-4075    

DOI:10.1002/jctb.5000651109

出版商:John Wiley&Sons, Ltd    

年代:1946

数据来源: WILEY

摘要:

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 st

ISSN:0368-4075    

DOI:10.1002/jctb.5000651110

出版商:John Wiley&Sons, Ltd    

年代:1946

数据来源: WILEY