160 Scientific Intelligence. 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry. 



1. A System of Physical Chemistry ; by William C. McC. 

 Lewis. In Three Volumes; Vol. Ill, Second Edition. Quan- 

 tum Theory. 8vo, pp. 207. London. 1919. (Longmans, Green 

 & Company. Price $2.50 net.) 



In the last thirty years, there has been an enormous increase 

 in the quantitative data of physical chemistry. Along with this 

 increase, have come attempts, many remarkably successful, to 

 account for the facts observed. Van ? t Hoff's and Arrhenius' 

 theories of dilute solutions and Nernst's heat theorem are well- 

 known illustrations in point. Planck's quantum theory is a 

 modified system of statistical mechanics which was proposed 

 originally to account for some of the facts of radiation. The 

 theory has more recently found application in other ways, such 

 as in the explanation of the heat content of substances and the 

 variation of heat content with temperature. 



Professor Lewis, in his book, presents very well indeed what 

 has been accomplished by applying the quantum theory and he 

 reviews much of the literature on the subject, which is not yet 

 so extensive as to make this impracticable. The theory and its 

 application are not simple but the book can be recommended to 

 students who wish to enter this field. h. w. f. 



2. An Introduction to the Physics and Chemistry of Colloids; 

 by Emil Hatschek. 12mo, pp. 116. Philadelphia, 1919 (P. 

 Blakiston's Son & Co. Price $1.50 net). — This is the third 

 edition of a useful little book of British origin, giving a very 

 satisfactory outline of the fundamental facts, theories, and 

 methods of investigation of this increasingly important branch 

 of chemistry. It is a book that can be highly recommended to 

 students of chemistry who wish to familiarize themselves with 

 the points of view, the technical terms and the important practi- 

 cal applications of the subject. h. l. w. 



3. Colloidal Chemistry ; by Jerome Alexander. 12mo. pp. 

 90. New York, 1919 (D. VanNostrand Company. Price $1.00 

 net). — This little book by an American author gives a very 

 satisfactory introduction to the subject. The author states that 

 he has attempted to compress within very limited space the most 

 important general properties of colloids and some of the prac- 

 tical applications of colloidal chemistry, and it is his hope that 

 it will be helpful in extending the sphere of interest in this 

 fascinating twilight zone between physics and chemistry. There 

 is no doubt that the book is an excellent one for its purpose and 

 attention may be called particularly to the fact that more than 

 one-half of its contents is devoted to a very interesting discus- 

 sion of the practical applications of colloidal chemical principles. 



h. l. w. 



