NATURE 



381 



THURSDAY, JANUARY 17, 1918. 



UANVALS FOR THE CHEMICAL 

 LABORATORY. 



(1) Standard Methods of Chemical Analysis. 

 Edited by Wilfred W. Scott and others. Pp. 

 xxxi + 864. (New York: D. Van Nostrand 

 Company ; London : Crosby Lockwood and 

 Son, 1917.) Price 305. net. 



(2) The Theory and Use of Indicators: An 

 Account of the Chemical Equilibria of Acids, 

 Alkalies, and Indicators in Aqueous Solution, 

 with Applications. By Dr. E. B. R. Prideaux. 

 Pp. vii + 375. (London: Constable and Co., 

 Ltd., 191 7.) Price 125. 6d. net. 



(3) Technical Handbook of Oils, Fats, and 

 Waxes. By P. J. Fryer and F. E. Weston. 

 VoL i.. Chemical and Generah Pp. viii + 279. 

 (Cambridgfe Technical Series.) (Cambridge: 

 At the Univ'ersity Press, 191 7.) Price 9.?. net. 



(i) p^'^ the analyst whose work embraces a 

 ^ wide rang-e of problems it is comforting 

 to have at hand a book which can be trusted to 

 indicate forthwith the best, or at least the usual, 

 methods of solving such problems. It obviates an 

 undue expenditure of time on the searching of 

 files and indexes, and facilitates the comparing of 

 one process with another, which is usually a neces- 

 sary preliminary to attacking the task in hand, if 

 that task is a new one. 



To a large extent the volume under notice is a 

 work which would be classed as a "laboratory 

 comfort " of the kind indicated. It is a very good 

 selection of " standard methods." The " chemical 

 analysis," however, for which these standard 

 methods are given is largely confined to inorganic 

 substances. True, there is a part devoted to 

 special subjects, which includes sections on the 

 analysis of some organic products, such as oils, 

 fats, waxes, and coals ; but in the main the work 

 is concerned with inorganic analysis. 



Beginning with "aluminium " and ending with 

 "zirconium," the elements are taken in order, and 

 under each heading are given, first, the chief 

 physical data, namely, the atomic weight, specific 

 gravity, melting point, boiling point, and the 

 oxides formed by the element. Next, the charac- 

 teristic chemical reactions for identifying the sub- 

 stance are given, and then follows a selection of 

 methods for its quantitative determination. These 

 include gravimetric, volumetric, and electrolytic 

 processes, of which a judicious choice has been 

 made. Any preliminary treatment required by the 

 substance is described under directions for the 

 "preparation and solution " of the sample and its 

 separation from interfering substances. 



Many of the newer processes are included, such 

 as the estimation of nickel by means of alpha- 

 benzildioxime and by dimethylglyoxime, and the 

 determination of sulphates with benzidine hvdro- 

 chloride. A method for the determination of car- 

 bon in steel by direct combustion is given, by 

 which, it is claimed, accurate results can be ob- 

 tained in ten minutes : the improvement lies in 

 NO. 2';i6, VOL. lOol 



supplying a rapid current of oxygen, instfeadof a 

 slow one as formerly. A welcome feature of the 

 -work is the inclusion of the principal " rare " 

 elements amongst those dealt with. In- the special 

 part the analysis of alloys, cements, coal, gas, 

 paint, and water, and the assaying of gold aad 

 silver are described, as well as the examination of 

 oils, etc., already mentioned. 



In general, the treatment of the subject-matter 

 Is lucid and concise; " lengthy exposition, theo- 

 retical dissertation, and experimental data," the 

 authors say, have been purposely avoided. Only 

 a few press errors Jiave been noticed, but two 

 distinguished names in chemistry have lost their 

 final " e," and appear as " Scheel " (p. 30) and 

 " Thorp " (p. 458). The lx»ok will be found very 

 useful as a convenient summary of modern ana- 

 lytical methods within the limits indicated. 



(2) Dr. Prideaux's book is mainly one for the 

 advanced student and the investigator. Its pur- 

 pose is to present a connected survey of the sub- 

 ject of chemical " indicators," i.e. the substances 

 used for showing by their changes of colour the 

 occurrence or progress of certain chemical re- 

 actions. Much has happened in this region of 

 chemical inquiry since the time when the Romans 

 used red wine as an indicator in testing the " hard- 

 ness " of drinking water. Even down to a rela- 

 tively short time ago the number of indicators in 

 general use was but small, e.g. litmus, logwood, 

 cochineal; and a few other substances. With the 

 development of synthetic organic chemistry, how- 

 ever, many more indicators have been brought 

 into use — nitro-derivatives, phthalein compounds, 

 aminophenol-methane products, and so on. More 

 important still, the mechanism of the changes 

 whereby the colours of these compounds are pro- 

 duced or altered has been carefully investigated, 

 both chemically, from the point of view of mole- 

 cular structure, and physically, from that of elec- 

 trolytic equilibrium in the solution. The author 

 gives an account of the results, and of present 

 views on the subject, including the allied matters 

 of light absorption and theories of colour. Many 

 references are supplied, and workers in this field 

 of research will find the book of considerable 

 utility. For general use its value would be en- 

 hanced by the inclusion of an elementary intro- 

 ductory chapter. 



(3) Messrs. Fryer and Weston's work is in- 

 tended to be a conspectus of the chemistry and 

 general scientific principles involved in the manu- 

 facture of oils, fats, and waxes. This industry is 

 essentially a chemical one, and a knowledge of the 

 fundamental principles of chemistry, both theo- 

 retical and practical, is indispensable for a really 

 intelligent conception of the nature of the pro- 

 cesses involved. The authors' experience is that, 

 whilst technical men in the industry generally have 

 a wide knowledge of the practical issues of the sub- 

 ject, this knowledge exists side by side with much 

 ignorance of the basic principles underlying such 

 issues. They, therefore, endeavour to explain, as 

 simplv as the theme permits, the theoretical basis 

 on which the technical processes rest. No doubt 



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