7 o6 SCIENCE PROGRESS 



competitor would be Abegg's Handbuch, and indeed, in all fairness, as it seems to 

 the reviewer the general scheme of the present work has been influenced — and 

 rightly influenced— to a certain extent by that admirable publication. But Abegg's 

 book has not yet been completed, and parts of it already require revision. The 

 present work, if brought out promptly, should take the premier place as far as 

 English-speaking people are concerned. 



The general plan of the present textbook is the fairly obvious one of division 

 according to the groups of the Periodic Table. Vol. I. deals with Group O, the 

 inert gases, and likewise includes in its first part an introduction of some 300 pages 

 dealing with the physico-chemical aspect of inorganic chemistry in general. This 

 introduction has on the whole been well written. Chapters Land II. deal with 

 stoichiometrical relationships and general properties. Chapter III. is devoted 

 to molecular weights and their determination for vapours, dissolved substances, 

 and pure liquids. In the writer's opinion the results obtained from drop-pipette 

 measurements, in view of the work of Kohlrausch and Lohnstein, scarcely deserve 

 even the short account given, and much the same may be said of Walden's 

 capillary relationships. Chapter V., on chemical change, is a useful epitome of 

 such subjects as types of reaction, thermo-chemistry, chemical affinity, equilibrium 

 and chemical kinetics — but why, oh why, is the term " heat-tone " (Warmetonung) 

 employed here and elsewhere ; it even finds its way into the index ! Part of 

 Chap. VI. is devoted to a short account of the electrolytic dissociation theory 

 which is in every way admirable. 



In dealing with complex salts in solution one misses a reference to Jacques' 

 book, but probably this appeared too late to mention. One very good feature is 

 the account of an accurate atomic weight determination (in Chap. VII.), illustrated 

 by the work of Richards on Lithium and Guye on Nitrogen. In the section 

 on specific heat we have a brief account of Einstein's application of Planck's 

 quantum theory to the problem, which serves to indicate the general up-to- 

 dateness of the work as a whole, though possibly a good deal more might 

 have been said on this particular point. For example, a reference might have 

 been made to Boltzmann's deduction of the Dulong-Petit law, as it was this 

 work which, by its very incompleteness, paved the way for the application of 

 the quantum idea to the problem. Chap. VIII. gives a good account of the 

 principle of the periodic table, its imperfections as well as advantages. In this con- 

 nection mention might well have been made of the work of Biltz, who has shown 

 that the periodicity in properties can be related (approximately at least) to the 

 periodicity of a more fundamental quantity, namely, the characteristic vibration 

 frequency of the atoms upon which " properties " to a large extent depend. 



The most serious omission in the whole of the introduction is the absence 

 of any discussion of electromotive force, and its bearing upon the quantitative 

 measurement of chemical affinity. As the other volumes appear we shall 

 certainly expect some information upon the electrometric properties of the 

 various metals, decomposition potentials, affinity and its variation with tempera- 

 ture, pressure, and concentration, oxidation and reduction processes, molecular 

 weight determinations by means of e.m.f., hydrolysis and electrolytic dissociation 

 by the same means. There is only a passing reference to electromotive force 

 as a means of determining transition points, and since it was considered necessary 

 to have an introduction at all, one is at a loss to know why this very important 

 mode of investigation has been omitted from the discussion. It would have 

 been a good thing too if the introduction had paved the way for the application 

 of such thermodynamical principles as Nernst's heat theorem, which we shall 



