Acad. P. P. Lazarev. Physicochemical Foundations of Higher Nervous Activity. Moscow, 1922. From the series Scientific Review, No. 1, 63 pp.

The present brochure is an attempt to set forth, in a generally accessible form, the totality of the newest investigations on the question of the mechanism of nervous activity. Among these investigations, a central place is occupied by the new ionic theory of nervous excitation created by the author. The foundations of this theory were laid by two major scholars of our time, the physical chemist W. Nernst and the biologist

J. Loeb, but only P. P. Lazarev succeeded, relying on certain considerations of a general character expressed by the first of the named scholars and on a number of facts and regular relations found purely empirically thanks to the work of the second, in constructing a finished theory of nervous processes connected with the broad application of the methods of mathematical analysis. In this respect the author is a follower of Helmholtz, and in the very essence of the matter his investigations represent a direct and necessary continuation of the grand edifice erected by the great physicist-physiologist in two monumental works devoted to auditory and visual sensations.

It must be acknowledged that Acad. Lazarev has very successfully coped with the difficult task of giving, in a small popular brochure, as clear an idea as possible of one of the deepest problems of contemporary natural science, for the understanding of which equally extensive and serious knowledge of physiology, physics, chemistry, and mathematics is needed.

In the first chapter the author dwells precisely on the question of the necessity of applying the methods of physico-mathematical investigation to biological phenomena. In doing so, he bases his interpretation of phenomena of a psychophysiological character on the following two propositions: 1. In living organisms there are observed no such forces and no such processes as could not be observed outside the organism (the postulate of Du Bois-Reymond), and 2. Under materially equal states of the corresponding parts of the brain, of the nervous system, and in general of the tissues being stimulated, the sensations or excitations accompanying them are identical.

In the second chapter the author treats the conditions of excitability of tissues and formulates mathematically the general law of excitation indicated by Loeb, deriving it from the experimentally based proposition that excitation must arise every time the number of ions in the medium of the living substance changes.

In Chapter III the ionic theory is consistently applied to visual, auditory, gustatory, and olfactory stimuli; in Chapter IV the same theory is applied to the propagation of excitation along nerves and to the activity of the nerve centers; in Chapter V—to the interpretation of reflexes and to the understanding of the activity of the nervous system as a whole.

In conclusion the author expresses several highly interesting considerations of a general character, some of which go far beyond the specifically psychophysiological sphere.

The author’s thought, expressed by him at the very end of the booklet, deserves special attention: “The study of social phenomena in connection with geophysical and cosmic phenomena must shed some light on the general law governing the mass actions of people, and make possible a scientific grounding for the study of the laws of human society.”

The profoundly absorbing interest of the questions touched upon by the author fully justifies the thought which, apparently, guided him in compiling this popular brochure: to disseminate the basic principles of the new teaching among the widest possible circles of educated people, in particular natural scientists and physicians, so that at least some small part of them might find in themselves sufficient strength and desire to overcome the difficulties connected with mastering physico-mathematical knowledge and, by their own personal labor, to increase the circle of persons engaged in the present-

at the present time, under the direction of Acad. Lazarev, on the development of one of the greatest and most profound scientific problems that Russian science has ever set itself.

L. Chugaev.