BIBLIOGRAPHY

Lehrbuch der Thermostatik das heisst des thermischen Gleichgewichtes materieller Systeme. Nach Vorlesungen von Dr. J. D. v. d. Waals bearbeitet von Dr. Ph. Kohnstamm. I Th. Allgemeine Thermostatik, zugleich dritte Auflage des Lehrbuch der Thermodynamik derselben Verfasser. Leipzig, Verlag J. A. Barth, 1927, Pp. XVI + 390.

Van der Waals—Kohnstamm. A Textbook of Thermostatics.

The third edition of the “Thermodynamics” of van der Waals—Kohnstamm, published under the new title “Thermostatics,” is of immense interest. The first two editions, already, which differed hardly at all from one another, introduced into the literature on thermodynamics much that was new and valuable. In the earlier editions the material was divided between two volumes in such a way that the first volume contained the general principles of thermodynamics, one-component systems, and the theory of capillarity; the second volume contained the general theory of multicomponent systems, the equilibrium of systems subject to external forces, and the theory of binary mixtures. The second volume was three times as large as the first and, together with a very detailed exposition of the special thermodynamics of binary mixtures, included a number of valuable chapters on general thermodynamics.

The new edition differs advantageously from the earlier editions in many respects. First of all, the title has been changed: since the whole book is devoted to the study of equilibrium systems, the book is called thermostatics; furthermore, the first volume now includes all the chapters concerning the general principles of thermodynamics for both one-component and multicomponent systems, while the second volume is left with the special thermostatics of binary mixtures (systems of class 1, in which no chemical reactions occur); the special character of the second volume is further intensified by the fact that in it binary mixtures are treated not only from the general thermodynamic point of view (as, for example, in Duhem), but also with the aid of the equation of state for mixtures given by van der Waals.

In its present form the first volume of “Thermostatics” is a completely independent and finished course and should find a considerably larger circle of readers than the second volume.

Among the distinctive features of the “Thermostatics” of van der Waals and Kohnstamm we shall point out the following. First of all, it is, of course, not a textbook.

even a prepared reader must ponder for a long time over a number of pages of this course: the book is written far from easily; moreover, throughout it very difficult questions of the thermodynamics of chemical processes are considered, at once deeply and briefly. In order to assess this book, the reader must know what the thermodynamics of the given question suffers from, where and what difficulties were encountered: otherwise it will seem to the reader tedious and unclear why the authors of the course dwell on the given question.

From the history of physical chemistry it is known that in his time Roozeboom encountered difficulty in the experimental study of binary systems (at the present time explained by the well-known law of independence of the volume of a system from pressure in monovariant systems) and turned for help to van der Waals; the latter directed Roozeboom to Gibbs’s works in this field, but since deciphering Gibbs’s theoretical works proved beyond Roozeboom’s powers, van der Waals was the first in Europe who had to interpret Gibbs for the purposes of applying his ideas to experiment. A profound study of Gibbs left its imprint on all van der Waals’s thermodynamic works, and his “Thermodynamics” (now “Thermostatics”) is the most direct exposition of the thermodynamics of physico-chemical systems from the standpoint of Gibbs’s doctrine. Very important are the chapters devoted to Gibbs’s postulate on equilibrium and its various formulations, in connection with the excellent exposition of the doctrine of characteristic functions; especially interesting and profound is the chapter on the application of this principle to systems in which chemical reactions are possible.

A major feature of “Thermostatics” is the critique and substantiation of the “phase rule,” carried out for the first time in thermodynamic literature; the paragraphs devoted to defining the concepts of “phase” and “component” are of profound interest. It is known that the phase rule is the only broad generalization in the thermodynamics of multicomponent heterogeneous systems, but a whole series of difficulties encountered in practice by the phase rule raised sharply the question whether it is a law or merely a tautology. Van der Waals and Kohnstamm prove, and successfully at that, that the phase rule is a law. In the latest edition a further new step has been taken, namely Kohnstamm shows that the phase rule can be derived without thermodynamics from molecular-kinetic considerations.

New in the 3rd edition is a chapter specially devoted to the axiomatics of the second principle; however, questions of this axiomatics also permeate other chapters. Kohnstamm’s views in this area are a reflection not only of the published works of Carathéodory, Lande, T. Ehrenfest-Afanassjewa, and others, but also the result of personal conversations with the last of the authors named. During the printing of “Thermostatics” there appeared Planck’s article, in which he shows that Carathéodory’s principle cannot be considered complete and

a proper replacement for W. Thomson’s principle, since Carathéodory’s principle does not take into account the statistical character of the second law of thermodynamics; further, Planck shows how the valuable feature found in Carathéodory’s method (the substantiation of the second law without the aid of cyclic processes and ideal gases) can be given in another way. Konstamm, however, believes that the difference in the views of Carathéodory (and his supporters) and Planck cannot affect questions of equilibrium in macroscopic systems.

Let us note one more new chapter in the 3rd edition of Thermostatics, devoted to Nernst’s theorem and to the principle of the unattainability of absolute zero. Altogether only 9 pages are allotted to these questions, and they are not so much expounded as debated; one senses Konstamm’s cool and restrained attitude toward these new points in thermodynamics.

The last two sections of the book, on equilibrium in systems under the action of external forces and on the thermodynamic theory of capillarity, have undergone no substantial changes in the new edition.

There is no doubt that van der Waals and Konstamm’s Thermostatics is a very substantial work, which no specialist can pass by; but, of course, it is not a textbook for beginners.

A. Rakovskii.