J. J. THOMSON. The Electron in Chemistry. Translated from the English by P. A. Kablukov and N. A. Zheleznova. Contemporary Problems of Natural Science, Book 36. State Publishing House, Moscow—Leningrad, 1927, pp. VI–156. Price 1 ruble 70 kopecks.

The book contains five lectures, delivered in 1923 at the Franklin Institute in Philadelphia, in which the author sets forth, chiefly in a vivid manner, his own views. In contrast to the generally accepted dynamic model of the atom, J. J. Thomson proceeds from a static model. “When an atom contains so many electrons, the orbits described by them are very complex, and the picture of numerous orbits presented to our imagination would be so motley and confused that it could not help us in forming a clear conception of the mechanism of chemical processes.” A system consisting of a positive nucleus and electrons at rest around it, however, cannot be stable if the forces acting between the electric charges of the constituent parts of the atom obey Coulomb’s law. Therefore the author postulates that, for distances of the order of \(10^{-8}\) cm, a more complex law holds, according to which attraction changes into repulsion as the distance decreases, as

V. N. KONDRAT’EV, N. N. SEMENOV, Yu. B. KHARITON. Electron Chemistry. Edited and with a preface by Acad. A. F. Ioffe. Contemporary Problems of Natural Science, book 39. State Publishing House, Moscow—Leningrad, 1927, pp. VI + 160. Price 1 rub. 75 kopecks.

A characteristic feature of the development of theoretical chemistry over the last ten years, which has led to such significant results, is the ever-growing cooperation between physics and chemistry. At the present time a considerable number of physicists are engaged with questions of the structure of the atom and the molecule—one of the fundamental problems of chemistry—while numerous chemists are making ever greater use of purely physical methods. The union took place on the basis of the electron theory and Bohr’s atom; from this arose a new chemistry, based—in contrast to the old one—not only on Avogadro’s rule and thermodynamics. One of the difficulties here was that the two sides did not always speak a language intelligible to one another. A great advance in this respect was the historic congress of the German Bunsen Society for Applied Physical Chemistry in 1920, devoted to questions of the structure of matter and chemical affinity, at which the principal reports were given by physicists. Subsequently there also appeared a number of handbooks on physical chemistry (Eucken, Eggert, and others) that devoted attention to the methods and results of contemporary atomic physics.

For the further penetration of the new ideas into the milieu of chemists, it was important to bring together, from a single point of view, the large body of experimental material accumulated in recent years. This is the task the authors of the book under review set themselves, taking as the basis for such a unification the properties of Bohr’s atom. The book is written in an accessible language and without a complicated mathematical apparatus. Among the literature, the latest works published up to September 1926 have been taken into account. Chapters I and II present the necessary data on the atom and the quantum laws. There follow in Chapters III and IV an exposition of the new views on valence, the nature of chemical forces, and the structure of molecules. The theory of the formation of Born’s polar molecules and the application of cyclic processes are described in detail. The question of the experimental verification of the numerical values of lattice energies, however, is not illuminated sufficiently fully. As for contem—