P. P. Lazarev. Current Problems in Biological Physics. Moscow, 1920.

Academician Lazarev works in the field of biological physics. His works are directly connected with the works of Helmholtz, Nernst, Loeb, and other European scholars who set themselves the task of applying physicochemical methods to biology. This new comparative field of physics—biological physics—is beginning to attract more and more attention. Physicochemical methodology, the only one that permits a quantitative accounting of the phenomena under study, was discredited and impeded in its broad application to biology and physiology, on the one hand, by the excessively hasty and superficial modeling of biological phenomena (Leduc and others), and on the other—quite possibly—by the crisis of the molecular-kinetic theory of matter at the beginning of the twentieth century (see, for example, Boltzmann).

It seemed that vital phenomena were so complex that they could not be fitted into the framework of the molecular-kinetic theories to which people wished to reduce the universum.

At the present time it has become possible to approach these phenomena from the standpoint of molecular-kinetic constructions (Smoluchowski and others), and also to apply broadly the method of principles, the method of thermodynamic analysis. And this has been achieved by the joint efforts of physicists, chemists, physiologists, and biologists. Not to speak of Helmholtz, who, like a giant of thought, stood in his time almost alone in his fundamental investigations in physiological optics and acoustics, it must be noted that the works of the biologist Loeb and the physical chemist Nernst opened a new era in biological physics, placing it on the firm foundation of quantitative accounting and of definite physicochemical modeling of phenomena.

At the present time there are whole journals devoted to biological physics (e.g. Zeitschrift für Biochemie und Biophysik).

As early as 1907–1908 and later (Zh. R. F.-Kh. O.), Lazarev published the results of his work on the photochemistry of vision—this process was investigated by him quite fully, and the influence of the brightness of light, the parallelism between absorbed and active energy, and the course of the process in time were clarified.

But it turned out that the differential relations underlying Lazarev’s theory of vision can also be extended to other physiological processes (auditory and gustatory stimuli). A general outline of these investigations, carried out by Lazarev at the institute under his direction, and an indication of possible new problems connected with them is given in “Current Problems of Biological Physics.”

The medium in which excitation proceeds consists of a protein solution and a solution of salts. Under the action of irritating agents the concentration of the ions of the salts changes. If the concentration passes a certain limit, chemical changes occur in the proteins. According to the ionic theory, the primary changes in the proteins are the beginning of the process of excitation.

At the threshold of stimulation there must be a certain relation between the concentrations of the active ions

\[ f(c_1,\ c'_1,\ c''_1,\ldots,\ c_2,\ c'_2,\ c''_2,\ldots)=0, \]

which, in the first approximation and with the use of the fact—found experimentally by Loeb—of the existence of antagonist ions, becomes

\[ \frac{c_1}{c_2}=\mathrm{const} \]

for the case of two kinds of antagonists.

The considerations set forth here are applied to the explanation of processes of stimulation by current (Nernst’s square-root law), and to visual, auditory, and taste sensations.

Lazarev has also studied the question of the propagation of excitation. It turned out that the chemical phenomena alone, diffusion, cannot explain the very great velocities observed.

As one of the immediate tasks Lazarev sets the further investigation of this question in connection with the study of the unequal conductivity of the plasma and the axial cylinder of the nerve.

Lazarev strives to approach the study also of such complex phenomena as the activity of the nerve centers. From the point of view of constructing a physicochemical theory, this question is complicated; the methodology for a physical approach has not yet been developed. Therefore the considerations of P. P. Lazarev are to a significant degree hypothetical, and not everyone agrees with many of them (for example, the mechanism of suggestion—see issue 3, vol. I of the Proceedings of the Physical Institute under the Moscow Scientific Institute, 1920), but the author

“Current Problems” has the right to note not only what has already been done and completed, but also what is still being developed and is being planned for the future. In conclusion it should be noted that biological physics embraces an extremely broad field of phenomena, and the author of “Current Problems” was of necessity compelled, on the one hand, to give the exposition an individual coloration, and, on the other, to narrow the range of phenomena considered.

For example, an extremely interesting and important field of biological physics for physiology and biology has not been touched upon, the foundations of which were laid by Van’t Hoff, who as early as 1896 gave his well-known law on the influence of temperature on purely chemical and physiological processes. True, the main direction of Van’t Hoff’s work (diffusion, osmosis) may, perhaps against his will, have directed biological thought toward a diffusional interpretation of many processes, e.g. processes of absorption, which is not always correct, as Fischer had already shown experimentally, and which can also be substantiated theoretically.1

B. Ilyin.

1. In connection with Lazarev’s works see, for example, Kries, ZS. f. Elektrochemie, 18, p. 465 (1912); Trendelenburg, Ergebnisse der Physiologie 1914, p. 16; V. Henri, Archives des Sciences, physys 1918; Loeb, Proc. Nat. Acad. of Sciences, 1915; Przibram, Experimentelle Zoologie, vol. IV, 1913. ↩