REVIEWS 491 



and an effort has been made to meet these as they normally arise. The 

 text is divided into twenty-six chapters which, considering the small size of 

 the book, contain in all quite a considerable amount of information. The 

 subject-matter, which is everywhere clearly set forth, follows the conventional 

 arrangement according to which aliphatic and aromatic compounds are 

 segregated in different parts of the book ; but for the convenience of com- 

 parison, the end of each of the earlier chapters gives a reference to a subsequent 

 chapter in which the corresponding group of aromatic compounds is dealt 

 with ; this is quite a good idea, and facilitates the use of the book for those 

 who prefer to study aliphatic and aromatic compounds together. 



P. H. 



The Physical Chemistry of the Metals. By Rudolph Schenck, Professor of 

 Physical Chemistry in the Technischen Hochschule in Aachen. Trans- 

 lated and annotated by Reginald Scott Dean. [Pp. viii + 239 with 

 114 Figures.] (New York : John Wiley & Sons ; London : Chapman & 

 Hall, 1919. Price 175. 6d. net.) 



This textbook, the outcome of a series of lectures by Prof. Schenck to the 

 engineers of the Rhenish industrial district, covers an extremely wide field, 

 ranging from the physical properties of the metals to the complex chemical 

 reactions occurring in the blast furnace, and the roasting of ores. The wide 

 scope of the work renders impossible the full development of all aspects of the 

 subject within the limit of 240 pages. 



A valuable feature of the book is to be found in the numerous tables of 

 physical constants of the metals and their alloys. The vapour pressures, 

 solidification curves and the structure of alloys are dealt with at some length, 

 and these properties are discussed with abundant references to particular 

 examples and widely illustrated by diagrams. Considerable attention is 

 paid to the electronic theory of the conductivity of metals, while on the other 

 hand the treatment from the point of view of the phase-rule is somewhat 

 fragmentary. 



The alloys of iron with carbon and of copper and other metals with 

 their oxides and sulphides are surveyed, and many excellent micropho- 

 tographs are given, illustrating the changes in the structure of steel on heat 

 treatment. The chemical equilibria of oxidation and reduction reactions, 

 occurring in the manufacture of metals from their ores, are treated exhaustively, 

 and some previously unpublished data bearing on these problems are included. 

 The theory of blast furnace reactions, which is presented, lays great stress on 

 the effects of the composition of the gas phase on the heterogeneous equilibria 

 between the oxides of iron, cementite, iron and the oxides of carbon. The 

 " roasting reactions " occurring when copper and lead sulphides are heated in 

 oxygen are treated similarly. 



This interesting survey of the physical chemistry of the metals should 

 prove especially useful to metallurgists and technical chemists. 



Margarine. By William Clayton, M.Sc. Monographs on Industrial Chem- 

 istry. [Pp. xi -j- 187, with 24 illustrations.] (London : Longmans, 

 Green & Co. Price 14s. net.) 



Since the Franco-Prussian War created the demand for a fat that should 

 be a satisfactory substitute for butter, great advances have been made, so 

 that to-day, as a result of the Great War, we find Margarine established as 

 a common, almost universal, article of diet. To produce an article which 

 should be a chemical approximation to butter would seem to have been no 

 very difficult matter, but to produce an article equivalent in taste and 

 nutritive value, in texture and stability, is an achievement not to be won 

 in a day. The problem, at first one for the chemist, now demands the 



