NIKOLAI ALEKSEEVICH
UMOV

FROM THE HISTORY OF PHYSICS

NIKOLAI ALEKSEEVICH UMOV

(1846–1915)

E. V. Shpolsky

Among Russian physicists of the recent past, the figure of Nikolai Alekseevich Umov is one of the most vivid and attractive. An outstanding physicist—theorist and experimenter, a scientist of rarely high culture, a brilliant lecturer, and a public figure of broad scope, he unfailingly drew people to himself by his crystalline purity.

N. A. Umov was born on January 23, 1846, in Simbirsk (now Ulyanovsk). His grandfather on his father’s side, Pavel Mikhailovich Naumov, was a nobleman and a wealthy landowner. The children of P. M. Naumov by a serf peasant woman, who did not wish to marry him so as not to quarrel with her relatives, received the surname Umov. One of them—Aleksei Pavlovich—was the father of N. A. His mother—née Susokolova—was of merchant origin. Apparently, the children inherited little from the former fortune of P. M. Naumov. In any case, the family of N. A. Umov was of modest means. His father, A. P. Umov, was educated at the medical faculty of Kazan University and served all his life. Medicine, however, was only A. P. Umov’s profession, not his favorite pursuit. The chief passion, which he preserved to the end of his life, was systematics and the biology of butterflies. He assembled a most valuable collection, comprising several tens of thousands of specimens; after his death the collection was divided between two universities—Moscow and Odessa, where two of his sons served as professors*).

The early years of Nikolai Alekseevich’s life passed in an atmosphere typical of not wealthy noble families: in childhood—a home education under the guidance of governesses, with compulsory study of foreign languages; then the governesses are replaced by teachers, among whom N. A. remembered with particular gratitude F. A. Ivanov, who first instilled in him a love of mathematics. Finally, there came

*) N. A. Umov’s brother, V. A. Umov, was a professor of civil law at Moscow University. He died young.

the time came to enter the gymnasium. However, N. A.’s father did not want his children to finish the Simbirsk gymnasium and moved with his family to Moscow. At the age of 12, N. A. entered the 3rd class of the 1st Moscow Gymnasium. Here he had the good fortune to be a pupil of one of the most outstanding Russian teacher-physicists—Yakov Ignat’evich Veinberg. Here is what N. A. later wrote about his teaching:¹ “He instilled love and faith in science; simple, clear, and engaging conversations from the field of natural science had an indelible influence on the children and youths who listened to him with tense attention. I was a pupil of the 3rd class when Yakov Ignat’evich taught us mathematics, and later, in the higher classes, physics. I do not remember a lesson to which he would have related only formally; I do not remember a dull lesson.”

In 1863 Umov finished the gymnasium and entered Moscow University, in the Faculty of Physics and Mathematics. At Moscow University N. A. Umov received an excellent mathematical education. Among the professors under whom N. A. studied, one should note the mathematicians N. V. Bugaev, A. Yu. Davidov, and V. Ya. Tsinger. Astronomy was represented by F. A. Bredikhin, mechanics by F. A. Sludskii. The position of physics was less favorable. The professor of physics was N. A. Lyubimov. He was, undoubtedly, a good teacher and a very active writer. Through numerous public lectures and lecture courses, accompanied by effective demonstrations, he did much to popularize physics. He authored a good physics textbook for secondary school, interesting for its historical excursions. His large, unfortunately unfinished, History of Physics (3 volumes appeared; the last ends with the epoch of Galileo) is still of interest; he also authored a monograph on Descartes (434 pages), containing a translation of the Discourse on Method “with explanations.” However, N. A. Lyubimov was not a physicist-researcher* and in the second half of his activity devoted himself almost entirely to journalism, and moreover of an extremely reactionary tendency. Here is what N. A. Umov writes about his physics teacher: “The pedagogical activity of N. A. (Lyubimov) at Moscow University undoubtedly represented a significant step forward. In organizing the teaching of physics, it was necessary to begin almost with the alphabet, and bringing it to the perfection which it attained in the hands of N. A. required great efforts and uncommon abilities. N. A.’s labor was a great acquisition

* In his recollections of N. A. Lyubimov, N. A. Umov writes about Lyubimov’s master’s dissertation², “The Fundamental Law of Electrodynamics and Its Applications to the Theory of Magnetic Phenomena”: “We do not find in it an independent scientific contribution, but we have before us, in the words of the author himself, in a careful restoration of the course of discoveries of Ampère—the first experiment in the study of the logic of discoveries in their history.” Of Lyubimov’s doctoral dissertation, Umov writes in the same place only the following: “This experimental investigation was carried out by him in the university physics cabinet in wintertime, and N. A. (Lyubimov) sometimes had to spend the night next to the room where these experiments were being performed.”

NIKOLAI ALEKSEEVICH UMOV

in the history of the Department of Physics of Moscow University, but this was only along the way. The reason for the fascination experienced by N. A. at lectures in Paris*) lay, of course, not in the brilliance of the experiments that were performed, but in the fact that the lecturers were Regnault, Claude Bernard, Flourens, Desains, who were not merely intermediaries between science and the audience, but served the movement and development of knowledge. The tasks of a university department did not take hold of the whole of N. A.’s activity. On the new path his work acquired an ever more publicistic tone, drawing him into fields far removed from the immediate tasks of a professor of physics.

Only in the last year of his time as a University student (in 1866) did Umov attend a course of mathematical electrostatics, then delivered by a still young instructor, but already an outstanding physicist, A. G. Stoletov. This course was written down by Umov and published in lithographed form. According to P. P. Lazarev, Stoletov’s influence on Umov’s development was very great.

An undoubted influence on N. A. was exerted by his professors of mathematics, especially N. V. Bugaev. A chance circumstance brought Umov into close contact with Bugaev. In his student years N. A. displayed many-sided activity. He not only, together with his comrades, organized a student mathematical circle, but also took an active part in the student “Self-Education Club,” in which the chief figure was A. I. Chuprov—then a student of the Faculty of Law, later a well-known professor of political economy at Moscow University. A. I. Chuprov drew up a memorandum on the necessity of a broad organization of popular education. This memorandum was lithographed and circulated in the lecture halls. In addition, some students undertook to deliver it to professors, in order to prompt them to active work in this direction. N. A. Umov undertook to distribute Chuprov’s memorandum among the professors of the Faculty of Physics and Mathematics, but he met with a sympathetic response only from N. V. Bugaev. Having thus become acquainted with Umov, Bugaev drew attention to the talented student and exerted a great influence on his scientific development. It was precisely on Bugaev’s advice that N. A. set about studying the works of the outstanding representatives of mathematical physics—Lamé, Clebsch, Clausius. This study left its mark on N. A. Umov’s first works, which were wholly devoted to mathematical physics.

In 1867, i.e., at the age of 21, N. A. graduated from Moscow University with the title of candidate.**) On September 9, 1867, the Council of Moscow University resolved to leave N. A. at the university for 2 years “for improvement in the sciences,” with a stipend of 400 rubles a year, beginning in April 1868. In the interval of time

*) At the beginning of his career N. A. Lyubimov was on a two-year assignment abroad and in Paris attended the lectures of a number of scholars listed later by N. A. Umov, and also worked in Regnault’s laboratory (approx. Ed. Board).

**) This title was given to those who had completed the University with distinction; it has nothing in common with the present degree of candidate.

between 1867 and 1870 N. A., alongside preparing for the master’s examination, taught physics at the 2nd Women’s Gymnasium and lectured at the so-called “Lubyanka Women’s Courses”). In 1870 N. A. published in the Mathematical Collection his first scientific work, “Laws of Oscillations in an Infinite Medium of Constant Elasticity” (Mathematical Collection, vol. 5, pp. 189 and 252, 1870). In this work N. A. skillfully uses the method of curvilinear coordinates, which was the result of his study of the works of Lamé, who developed this method. In the same year, 1870, N. A. passed the master’s examination in physics, which required very diligent work). Despite this, and despite the fact that during preparation for the examinations N. A. was compelled, for earnings, to teach in a secondary school, already in the following year, 1871, he brilliantly defended his master’s dissertation), which was entitled “Theory of Thermomechanical Phenomena in Solid Elastic Bodies.” This work, like N. A.’s first work, was mathematical in character (on it see the review by Prof. F. N. Shvedov cited below). In the same year, 1871, even before the defense of his master’s dissertation, N. A. was elected by Odessa University as “acting docent in the department of physics.” In the “Proceedings of the Meetings of the Imperial Novorossiisk University” (Notes of the Imperial Novorossiisk University, vol. 8, p. 263, 1872) we read:

“On November 22 they heard: ... The submission of the same faculty: ‘Professor Shvedov proposed to the faculty that Candidate of Mathematical Sciences N. A. Umov, who had passed at Moscow University the examination for the degree of master, be elected acting docent in the department of physics. As a result of the balloting held on October 18, all seven votes participating in it proved to be affirmative. Therefore the Faculty of Physics and Mathematics has the honor to request the Council to elect Mr. Umov acting docent in the department of physics. The original submission of Professor Shvedov is attached herewith.’”

*) The “Lubyanka” Women’s Courses, founded in 1869, had the aim of supplementing the insufficient preparation for university education provided by the women’s gymnasia of that time. After the establishment in Moscow of the Higher Women’s Courses of Prof. V. I. Guerrier, the Lubyanka Courses were transformed (in 1882) into a faculty of physics and mathematics with a university curriculum.

**) “Passing the master’s examinations,” writes P. P. Lazarev, “at that time represented a very difficult task at Moscow University. For preparation in the special subjects an enormous number was recommended not only of major courses devoted to both experimental and theoretical physics, but also the broadest journal literature in English, German, and French. An examination lasting many hours, requiring the applicant to answer for not only general concepts and ideas about the subject, but also knowledge of a number of details and mathematical derivations, which had to be kept in mind.”³

***) The exact date of the disputation has not been preserved. N. A.’s confirmation in the degree of master by the Council of Moscow University took place on April 15, 1872, on the basis of which A. I. Bachinskii concludes that the defense took place at the end of 1871.

NIKOLAI ALEKSEEVICH UMOV

Prof. Shvedov’s submission, mentioned in this excerpt from the minutes, is very interesting. It reads: “At one of the preceding meetings of the faculty it was recognized as necessary to have one more instructor in physics, in view of the breadth of this subject and its importance for all branches of natural science. At the same time the dean of the faculty announced the request of Mr. Umov, candidate of the physico-mathematical sciences of Moscow University and master’s student in physics, who wished to stand for election to the position of instructor, who had placed in the Mathematical Collection an article on mathematical physics and had received excellent written reviews from many members of Moscow University. When asked on this occasion for my opinion, I stated that although Mr. Umov’s article does demonstrate his acquaintance with one of the branches of mathematical physics, nevertheless it is important for the faculty that an instructor in such a new and not yet established science as mathematical physics should be able to take a critical attitude toward its problems, which for the most part have not been finally resolved; this is why I asked the faculty to postpone the voting until Mr. Umov should give me an opportunity to judge to what extent he is capable of dealing with the raw material of science. At the present time Mr. Umov has resolved my doubts in the most satisfactory way, and moreover in his own favor, by sending me a detailed account of his new work, his master’s dissertation, submitted to the faculty of Moscow University and approved by it. The aim of this work is to connect the theory of elasticity with the mechanical theory of heat. Not confining himself to the investigation of special cases of identical temperature and identical normal pressures and tensions throughout the body, which had already been studied by Thomson, Clausius, and Zeuner, Mr. Umov approached the question from as general a point of view as possible: when the temperature is distributed non-uniformly throughout the body, and the latter experiences different pressures and tensions in different parts. In this case the question becomes especially complicated, since, owing to thermal conductivity, the temperature of the different points of the body changes with time, and Mr. Umov would have had to deal at once with two theories—elasticity and thermal conductivity—founded on different principles, had he not arrived at the fortunate idea of connecting these theories by one common principle. For this purpose he used the well-known principle of the conservation of energy. As a criterion of the soundness and generality of Mr. Umov’s investigations there may serve the circumstance that from his equations there follow, as special cases: the second law of the mechanical theory of heat, the equations of equilibrium of solid elastic bodies, and the equation of thermal conductivity. On the basis of such merits of this work, I have come to the conviction that our faculty, in the person of Mr. Umov, can acquire not only an instructor capable of transmitting results obtained by others, but also a specialist capable of advancing science. I therefore have the honor most respectfully to request the faculty to subject Mr. Umov to balloting for the correcting position of docent in mathematical physics and, in the event of his election, to petition the council for his confirmation.”

At the beginning of 1872 N. A. was appointed a staff docent, in 1875 an extraordinary professor, and in 1880, i.e. at the age of 34, an ordinary professor of Odessa University. From the moment of his appearance in Odessa, Umov made the most favorable impression on everyone. I. M. Sechenov, who in those years was a professor at Odessa University, notes in his autobiographical notes: “There arrived from Moscow to the chair of mathematical physics a very young man, N. A. Umov, who made a great impression with his introductory lecture.”

The situation at Odessa University was peculiar. Among its professors there were a number of outstanding scholars. It is enough to name the already-mentioned I. M. Sechenov, I. I. Mechnikov, and A. O. Kovalevsky. However, the general atmosphere at the University was unfavorable. I. I. Mechnikov^5 characterizes this situation as follows: “Odessa University, from the very time of its foundation, was distinguished by a special abundance of unpleasant squabbles. As an institution still new at that time, it did not merge with the city. The professors, mostly natives of other universities, were newcomers in Odessa and did not participate, with extremely rare exceptions, either in municipal administration, or in banks and similar enterprises. Moreover, there were no other higher educational institutions in Odessa in which university professors could have held positions. In view of this, their activity was concentrated exclusively in the University. All the time free from lecturing the professors spent in the ‘lecture hall,’ where mainly the bones of comrades were picked over, ‘parties’ were created, strengthened, and destroyed. Elections of new professors and officials (deans, secretaries, etc.) formed the most frequent topic of conversation. Personal sympathies and antipathies played a very important role in this. Especially noticeable was the antagonism between professors of local origin, i.e. Little Russians, and Muscovites. The scholarly evaluation of candidates was for the most part subordinated to personal feelings.”

With the arrival of N. A. in Odessa a close circle was formed, at the center of which were N. A., I. M. Sechenov, and I. I. Mechnikov. Here is what I. M. Sechenov^7 writes about this circle: “In the following (1882) year there began to take shape that truly friendly circle because of which I love Odessa to this day... For a friendly circle of working men a family home is as necessary as a warm, cozy corner for the weary... Such a connecting link—the salon of the circle—became the Umovs’ apartment. The host, in addition to refined amiability, proved to be an inveterate lover of good eating; the hostess represented the element of cordiality; I had the significance of an uncle not yet quite grown old, and the soul of the circle was I. I. Mechnikov... Our circle constituted a party in the University only in the following sense: we sought neither deanships nor rectorships, did not try to attach our relatives to the University, and went neither with complaints nor with requests to the trustee, which quite a few in the University occupied themselves with... We lived quietly.... in the morning”

for work in the laboratory, and in the evening for the most part in our salon for friendly conversation, and so on.”

The first two years of N. A.’s work in Odessa were extraordinarily fruitful. During 1873–1874 he published, in Russian and in German, works that were all devoted to the development of the most important idea of the motion of energy. In the first works of this cycle N. A. makes concrete the concept of potential energy, considering it as the kinetic energy of certain media “imperceptible to us.” This point of view, also supported by H. Hertz and J. J. Thomson, corresponded to the spirit of Umov’s general philosophical worldview (see below, p. 141). From this hypothesis concerning the nature of potential energy he draws the following conclusion: if all energy in general is kinetic energy, then it is always possible to indicate the place where it is located. This place is the place of the particle that carries the kinetic energy. But in that case it is natural to raise the question of the motion of energy.

In his subsequent works Umov no longer binds himself to the special hypothesis concerning the nature of potential energy, but is guided exclusively by the principle of conservation of energy. Having formulated the concept of the density of energy at a given point and of the velocity of its motion, he writes the differential equations for the motion of energy in an elastic solid body and in a liquid. For the case of a wave field in an elastic medium he arrives at the conclusion that there exists a flux of energy propagating along the ray. Thus, in Umov’s works as early as 1873 there were already clearly formulated the fundamental premises which ten years later were successfully used by Poynting in his theorem on the flux of energy in the electromagnetic field.

At the present time these ideas have entered textbooks and are common knowledge. In the seventies of the last century, however, they were not only entirely new, but also seemed highly controversial to many. It should not be forgotten that the very idea of the field had not yet at that time entered into common use among physicists. Faraday was poorly understood, and Maxwell’s Treatise on Electricity and Magnetism appeared in 1873. Still greater difficulties were associated with the perception of the idea of the possibility of the motion of energy, since energy was regarded only as a certain mathematical function and was not ascribed a substantial character. This explains the fact that when Umov collected his remarkable works and presented them in 1874 as a doctoral dissertation at Moscow University, this dissertation met with violent objections from official and unofficial opponents, despite the fact that one of the official opponents was such an outstanding physicist as A. G. Stoletov. Umov’s biographer, A. I. Bachinsky,^7 describes N. A.’s doctoral disputation as follows: “The official opponents were Professors Stoletov and Sludsky (the mechanic E. Sh.); Professor Tsinger appeared as unofficial opponent. The opponents hotly criticized the author’s basic ideas; the disputation lasted about six hours and was very passionate. A well-known phenomenon was repeated: a major

idea, once born from the head of its author, to make its way in the surrounding conservative milieu. N. A. long retained an unpleasant memory of the course of his doctoral disputation. On the other hand, it undoubtedly later gave him much satisfaction to see how his principal and most disputed ideas became generally recognized and “current.”

At present N. A. Umov’s priority in the question of the motion of energy is generally recognized in the scientific literature. Thus, for example, in the fundamental Encyklopädie der mathematischen Wissenschaften the following is said on this subject[^8]: “N. Umov, already in 1874, solved in a completely general way the problem of the motion of energy in liquid and elastic media. However, focused attention was drawn to this view only after Poynting, on the basis of Maxwell’s equations, represented the flux of electromagnetic energy by a very simple law.”

Having returned to Odessa after the defense of his doctoral dissertation, N. A. continued to work intensively. However, he no longer returned to the problem of the motion of energy. It is very probable that this was due to the sharp opposition, on the part of persons authoritative for N. A., which his first work encountered. To give an idea of the range of N. A.’s interests at that time, we shall cite the titles of some of his published works: “On fictitious interactions between bodies immersed in an elastic medium,” “On the stationary motion of electricity in conducting surfaces of arbitrary form,” “The geometrical meaning of Fresnel’s integrals.” In this last work not only is an elegant geometrical interpretation of Fresnel’s integrals given, but an apparatus for their mechanical calculation is also described.

In addition to the listed and some other theoretical works, in Odessa N. A. also carried out a number of works of an experimental character.

The conditions for experimental work were extremely unfavorable. The physics cabinet of Odessa University was poor, and the small funds allocated for the work were at the disposal of Shvedov, with whom N. A.’s relations were far from smooth. Therefore Umov was forced to choose such problems for which one could manage with the simplest or even homemade apparatus. These experimental works of N. A. were devoted to questions of the solubility of salts and the diffusion of solutions. In the course of the work N. A. devised a number of simple and ingenious devices for studying diffusion.

Umov’s pedagogical activity in Odessa was very many-sided. He lectured on all branches of theoretical physics. Part of his courses was published. Such is his Course of Mathematical Physics, I. Introduction. Odessa, 1878 (contains the theory of vectors and the theory of potential); further: “From Lectures on Mathematical Physics” (I. Theory

infinitely small oscillations near a position of stable equilibrium. II. Oscillations of a system with one degree of freedom. Resonance and absorption), Odessa, 1883. The remaining courses were lithographed. In addition to lectures on theoretical physics, N. A. taught a course in measurement physics and organized a laboratory for students’ practical work, which at that time was a major innovation.

In 1893, after working in Odessa for 22 years, Umov parted with it and returned to Moscow. Here he at first taught (together with P. N. Lebedev) a course for medical students, and in 1896, after the death of A. G. Stoletov, he received the principal chair and the directorship of the physics cabinet. Among N. A.’s scientific works belonging to the Moscow period, one should note his important work on terrestrial magnetism (“Construction of a Geometric Image of Gauss’s Potential as a Method for Investigating the Laws of Terrestrial Magnetism”), highly valued by specialists in geomagnetism, and a series of experimental works concerning an interesting phenomenon discovered by him, which is observed in the diffuse reflection of light from colored surfaces. As is known, polarized light, upon diffuse reflection, is partially depolarized. Umov discovered that if the scattering surface is colored (colored paper or textile fabric), then for wavelengths corresponding to the absorption maximum of the dye the depolarization is smallest, while for wavelengths corresponding to the transmission maximum the depolarization is greatest. Conversely, when unpolarized light is reflected, the resulting partial polarization has its greatest magnitude at the absorption maximum. Making use of this phenomenon, Umov constructed a special instrument—a spectropolarimeter—which he successfully applied to the study of the reflection spectra of solid dyes and colored surfaces. Umov’s method proved to be considerably more sensitive than ordinary spectrophotometric methods.

N. A. took shape as a scholar in the epoch of the flowering of classical physics. New theories, which required a radical breaking of established conceptions, appeared toward the end of his life. At an advanced age such a break, as is well known, is psychologically very difficult. But N. A. understood the great significance of the new theories and strove to make his own contribution to their comprehension. In a note devoted to the theory of relativity, he gave a derivation of the Lorentz transformations from the condition of invariance of the wave equation; in another note, devoted to the quantum theory, he attempted to reconcile the unusual results of this theory with classical conceptions.

As a professor, N. A. did much to raise the level of physics teaching at Moscow University. A great achievement of his was the organization of the construction of the physical institute.

In 1897, in the article “A Few Thoughts Concerning Higher Technical Education,” N. A. wrote1: “Let us turn, for example, to one of the oldest Russian universities—Moscow University. It would seem that here, in this center of Russian enlightenment, we ought to have encoun-

...to establish an exemplary physics institute. Lectures in physics at Moscow University were attended by 900 people. There was also a physics institute—a shack in the courtyard of the old building, barely accommodating 40 working students. Anyone who had visited the physics institutes of Europe involuntarily felt a blush of shame when he looked at the physics institute of the first of the Russian universities.” N. A. wrote articles in newspapers and detailed memoranda, drawing attention to the urgent need to organize a large physics institute at Moscow University.

The main task which N. A. pursued in this was to create an institution that would make it possible not only to raise the teaching of physics to its proper level, but would also be adapted for scientific work.

“The political significance of a nation,” he wrote in an article on the future physics institute, “can be lasting on the condition that its cultural level corresponds to its political rise. In our time, weapons and courage are not the only factors ensuring success in the struggle of peoples for their development and existence... Museum, cabinet—these are the terms characterizing the former view: study; institute—this is the new view: study and create. Having obtained substantial appropriations for construction, N. A., together with P. N. Lebedev (at that time still a young scholar) and A. P. Sokolov, worked out in detail the design of the Physics Institute on the model of the best European institutes. The implementation of this plan, however, required the expenditure of great energy. “Observations over the construction and disputes about it took much time and strength from N. A.,” he later wrote in his autobiography. In the summer of 1903 the construction was completed, and in the autumn lectures began in that large physics auditorium which to the present day is one of the very best (if not the best) physics lecture halls in our country; and the solid four-story building of the Physics Institute even now, along with teaching laboratories and auditoriums, accommodates a large scientific-research institute.

If in Odessa N. A. devoted his energies almost exclusively to scientific work and teaching, then, having returned to Moscow, he developed broad scientific and public activity.

Elected in 1897 president of the oldest Russian learned society—the Moscow Society of Naturalists—N. A. took care to expand the activity of this society, himself read a large number of reports in it, and drew into its work a number of young physicists and chemists.

N. A. also took an ardent part in developing and improving the teaching of physics in the secondary school. He was one of the founders of the Pedagogical Society at Moscow University and served as chairman of the Section of Teachers of the Physico-Chemical Sciences. In connection with this interest in the secondary school he wrote a number of articles,

defending the need to expand the role of natural science as a counterbalance to classical education. N. A. returned to activity among teachers of physics at the very end of his life. When in 1912 the “Moscow Society for the Study and Dissemination of the Physical Sciences,” whose aims were chiefly pedagogical, was founded in Moscow, the Society elected N. A. as its first chairman. In 1913 he delivered a major address, “The Evolution of the Physical Sciences and Its Ideological Significance,” at the First All-Russian Congress of Teachers of Physics, Chemistry, and Cosmography. This address “was received with enthusiasm by the numerous listeners, who had gathered from all corners of Russia and filled the hall to overflowing” (A. I. Bachinsky, Essay on the Life and Works of N. A. Umov).

One must also mention yet another major cultural undertaking headed by N. A. In 1902, Privatdozent of Moscow University G. K. Rakhmanov (a meteorologist), a man of means, organized the publication of the popular-science journal Scientific Word. N. A. Umov was invited to be its managing editor. He brought the greatest scholars into close participation in this journal—I. M. Sechenov, I. I. Mechnikov, K. A. Timiryazev, V. O. Klyuchevsky, S. N. Trubetskoy, M. O. Gershenzon, and many others. This journal was so brilliant that it occupied an outstanding place not only in Russian but also in world literature. Suffice it to mention that it was here that K. A. Timiryazev’s famous Croonian Lecture “The Cosmic Role of the Plant,” Mechnikov’s “Studies on the Nature of Man,” Sechenov’s “Elements of Thought,” V. O. Klyuchevsky’s articles on Russian history, and much else were first printed. N. A. himself published here a number of brilliant articles of a broad scientific-philosophical character (“The Evolution of the Atom,” “Misunderstandings in the Understanding of Nature,” etc.). Unfortunately, this journal did not exist for long and in 1906, because of financial difficulties, closed down.

In 1911 Moscow University suffered a catastrophe. As a protest against the unlawful dismissal by the Minister of Public Education L. A. Kasso of the rector, the assistant rector, and the prorector, a large number of professors and privatdozents left the university*). N. A. Umov left as well. As a result he had to endure material privations, difficult for a man of advanced age. He moved from his comfortable apartment at the university to a modest private apartment, and his financial situation in general became difficult. A considerable part of his time at the end of his life he devoted to work in the so-called “Society for Promoting the Successes of the Experimental Sciences and Their Practical Applications named after Kh. S. Ledentsov” (abbreviated “Ledentsov Society”), of which he was deputy chairman. This Society had been organized with funds left by the testa—

*) For more detail on this history of the destruction of Moscow University by the tsarist Minister of Public Education, see the article by T. P. Kravets, “The Creative Path of Academician P. P. Lazarev,” UFN, vol. 27, issue 1, p. 16, 1945.

...to X. S. Ledentsov, and its task was to give material assistance to inventions and to scientific-research work. In this respect it played a positive role. Thus, for example, after P. N. Lebedev left the university, the “Ledentsov Society” allocated him considerable funds for the continuation of the work of himself and his pupils. The same society provided funds to I. P. Pavlov for a laboratory for the study of conditioned reflexes.* It also gave funds to numerous inventors.

N. A. Umov played a most important role in this society. He was one of its chief ideological leaders, who determined the very character and direction of the society’s work; he performed the difficult work of evaluating a whole stream of invention projects submitted to the “Society”; he invested great labor in the organization and running of the journal published by this society (“The Chronicle of the Society for Promoting the Advances of the Experimental Sciences and Their Practical Applications named after X. S. Ledentsov”).*

Leaving the university was hard for Umov not only because of material difficulties. Having become accustomed, over nearly five decades of university activity, to teaching and to work in the laboratory, after leaving the university he felt out of place, despite his extensive work in the “Society of Naturalists,” in the “Ledentsov Society,” and in the “Society for the Study and Dissemination of the Physical Sciences.” To continue his investigations of the phenomenon he had discovered, “chromatic depolarization,” Umov made use of the friendly assistance of Prof. Petrov, who directed the dye laboratory at the Moscow Higher Technical School. With the aid of his instrument—a spectropolarimeter, which had been built by the well-known optical firm Fuess—he carried out a large number of measurements of the polarization spectra of dyes, making use of the valuable collection of samples available in Prof. Petrov’s laboratory.

In 1914 N. A. showed signs of a serious illness, apparently a stomach ulcer. Being by nature a man of robust health, he paid little attention to the ominous symptoms, and at the slightest improvement began working intensely, returning home late from various meetings and from the laboratory and not observing the regimen prescribed for him. By the end of the year, however, his health had deteriorated so much that N. A. was forced to take to his bed. The last two months of his life were a rapid fading away. On January 2, 1915, he was no more.

As a person N. A. was extraordinarily attractive. Soft and delicate by nature, he was unshakably firm when the matter concerned moral principles. His whole imposing figure breathed nobility and spiritual beauty. Here is what I. I. Mechnikov wrote about him in his memoirs: “There could be no question of, for the sake of

*) N. A. Umov’s activity in the “Ledentsov Society” is described in greatest detail by A. I. Bachinsky in a brochure published by the society.

...that for some practical purpose this pure person would retreat from his convictions. That is why N. A. very soon won the love of his closest comrades and the respect even of his opponents. In Sechenov’s circle he acquired the reputation of an idealist, “far removed from everything earthly.”

Like many other outstanding Russian scholars, Umov often appeared with speeches, reports, and articles on general scientific topics. These speeches of his, carefully collected by his closest pupil and friend, Prof. A. I. Bachinsky, were republished in 1916 as the third volume of the Collected Works of N. A. Umov. Unfortunately, the publication of N. A.’s works, begun with this third volume, ended with it as well. There is no doubt that these speeches and articles, brilliant in form and profoundly interesting in content, were a significant contribution to the spiritual culture of our country. Many of them have retained their interest to the present day. In 1888, in the speech “In Memory of Clerk Maxwell,” written for delivery at the ceremony of Odessa University but not delivered, since the ceremony did not take place because of student unrest, N. A. expressed a number of bold ideas for that time. Thus, for example, he asserts that “the chemical atom is a microcosm” and that molecules are “not fabricated objects,” since they are “not identical in their mass or in their structure.”

Umov’s speech “A Physico-Mechanical Model of Living Matter,” delivered on December 20, 1901, at the general meeting of the XI Congress of Russian Natural Scientists and Physicians,[^14] made a great impression. It is interesting that this speech was delivered immediately after the speech of the histologist Prof. S. M. Lukyanov (later Chief Procurator of the Holy Synod), who spoke in defense of vitalism. Umov’s point of view is diametrically opposed; he begins his speech with the assertion: “Vitalistic theories are untimely: the epoch we are living through must serve not to separate, but to bring together the tasks concerning the organized and the unorganized in nature.” This speech by N. A. was subjected to attacks in the reactionary newspaper Novoe Vremya by a certain Ellpe (L. Popov). In his (unpublished) reply, N. A. points out that Lukyanov’s point of view is reduced in essence to the assertion that life is not only something natural, but also supernatural; but in that case the scientific investigation of the processes of life becomes altogether meaningless.

In his speeches and articles of general content Umov did not remain an impartial rapporteur or simply a popularizer of new ideas in physics, but always defined his own relation to the physical theories he expounded. It is interesting to trace the evolution of his physical worldview. In his first speeches Umov constantly returns to his beloved philosopher—Descartes—and notes with satisfaction those aspects of physical theories which he con...

Cartesian. In his speech “The Significance of Descartes in the History of the Physical Sciences,” delivered at the Moscow Psychological Society on October 12, 1896, on the occasion of the tercentenary of Descartes’ birth, Umov points out that the significance of this philosopher lies above all in the creation of a scientific system. In Umov’s opinion, “the plan of Descartes’ physical teachings retains its force even to the present day, and its framework has not yet been filled with scientific content.” Further, Umov notes Descartes’ importance in banishing Aristotelian doctrines “of internal forms, souls, or purposive strivings of dead matter... He [Descartes] expels from nature the entire legacy of scholasticism: hidden qualities, substantial forms, appetites, inclinations, and other concepts borrowed from the spiritual life of man.” And further: “The characteristic feature of Descartes’ doctrine—the expulsion from the science of nature of hidden properties and the indication of the possibility of explaining physical phenomena by motion—conditioned its vitality, and the scientific trend guided by Descartes’ principles is called Cartesian or kinetic.” Umov sees the essence of Descartes’ physical method in the fact that “every property of nature that cannot be brought under the categories of space and motion is excluded from the category of causes and transferred to the category of problems.” Having indicated that the Cartesian interpretation of force in mechanics must consist in the fact that “force, i.e., the cause that changes the motion of a body, is the motion of matter invisible to us surrounding the body,” Umov draws attention to the fact that precisely in this way this problem is solved in certain contemporary theories—in the works of H. Hertz and J. J. Thomson, who, in order to explain potential energy, admitted “hidden masses and hidden motions.” Throwing a bridge from Descartes to the physical theories of the nineteenth century, Umov sees in Hertz’s system of mechanics, with its banishment of forces, and in Helmholtz’s theory of cyclic motions, the direct development of Descartes’ ideas. However, already in the speech “Questions of Knowledge in the Field of the Physical Sciences”[^15] (1894) he notes with alarm that the clear picture of the elastic theory of light gives way in the second half of the nineteenth century to a more abstract electromagnetic theory, where a distinct mechanical conception of light vibrations is lost. “Instead of explanation there remain only formulas, drawn on an infinite parchment stretching through the whole universe!” Having pointed out a number of other troubling signs of the “deviation of contemporary views from Cartesian views,” Umov asks at the end of the speech: “Are we not standing, at the end of a half-century of continuous growth of natural science, at the limits of what is attainable?” And he immediately gives a reassuring answer to this question, indicating that the contemporary state of the picture of the world is one of the stages in the struggle of two opposing tendencies—the Cartesian, i.e., mechanical, and the Newtonian, i.e., dynamic—a struggle that also took place in the eighteenth century, “when a retreat along the entire line of Cartesian doctrines was heard.”

Six years later, in 1900, in his speech “The Contemporary State of Physical Theories,” Umov states with greater definiteness the po-

NIKOLAI ALEKSEEVICH UMOV

a revolution that took place in the worldview of physicists at the end of the nineteenth century. By the middle of that century the orderly and majestic edifice of classical physics had been erected. “Resting on the foundations laid by Galileo and Newton, classical physics constructed a mental image of phenomena accessible to our senses by decomposing finite phenomena into infinitely small physical elements.” Although this “decomposition” was carried out in the first half of the nineteenth century predominantly “by mathematical speculation,” the system of classical physics was distinguished by a remarkable capacity to adapt easily “to new acquisitions of experimental science.” Thus, for example, when heat was banished from science, the law of conservation of energy, kinetic gas theory, and its consequences were easily incorporated into the classical system. “It seemed to us who had accepted this system,” writes Umov, “that we held in our hands the key to understanding the physical world.” But toward the end of the nineteenth century this confidence was replaced by doubts; “scientists had to live through all the stages of dismantling the orderly edifice and to witness its reconstruction.” Umov notes that this new development of physics proceeded in the direction of rejecting the method of “physical decomposition,” that is, what he had earlier called the “Cartesian or kinetic worldview.” A powerful blow to this worldview was dealt by the successes of thermodynamics, which found a method for investigating phenomena occurring in “finite bodies” without delving into the question of their structure, but instead characterizing physical states by macroscopic parameters. An even more decisive blow to the worldview of mid-nineteenth-century physics was dealt by Maxwell’s electrodynamics, which likewise had a macroscopic character. Hertz’s discovery of electromagnetic waves was a triumph of Maxwell’s electrodynamics and ensured the success of the electromagnetic theory of light, which displaced the conception of light vibrations of the ether as a mechanically elastic solid medium and reduced the light wave to the conception of an alternating electromagnetic field.

The incompleteness of the classical system of physics gave rise to the need to create a new system, which Umov calls the energetic system in the form in which it was created by Helmholtz. This system rests on two general principles, namely, the principle of conservation of energy and Hamilton’s principle. Any mechanical picture of a phenomenon in the energetic system is superfluous; quantities having nothing in common with the quantities considered in classical mechanics may be used as parameters—for example, electromotive force, current intensity, and so on.

However, Umov is not satisfied with this phenomenological worldview. He recalls, in particular, that this system is not entirely general either, since Hamilton’s principle “contains conditions which are not always fulfilled in nature”; in reality it is not applicable to nonholonomic systems. As a way out of the situation, Umov again points to Hertz’s mechanics, the fundamental principle of which is the principle

of the straightest path—is free from the restrictions imposed on the applicability of Hamilton’s principle. Umov, faithful to his earlier ideas, also sees the advantage of Hertz’s system in that it “brings us closer to the old ideal of physics—to explain phenomena, understanding such an explanation as the subordination of all natural phenomena to one general law.”

Eleven years later, in 1911, in the speech “Characteristic Features of Contemporary Natural-Scientific Thought,”2 delivered at the Second Mendeleev Congress, Umov already unconditionally recognizes the collapse of mechanical physics and the triumph of the electromagnetic picture of the world. As a physicist, Umov perceives this evolution materialistically: he describes the discovery of the electron as the materialization of electricity; explaining the relation between mass and energy, which follows from the theory of relativity, he calls the application of this relation to radiant energy the materialization of this energy. In obvious inconsistency with this, idealistic phrases occur in his speech: “matter has disappeared...,” “the subsequent development of physics is a process against matter, ending with its exile.” Analyzing this speech, S. I. Vavilov3 justly notes, however, that “these words, unusual in Umov’s mouth, had only an external and terminologically idealistic character. In reality he was speaking of replacing the constant mass by the electromagnetic one... It is clear that for Umov the external world was a wholly objective world, and the ‘disappearance of matter’ was only an effective, though incautious, phrase to denote the variable character of Newtonian masses.”

Having reached mature age in the epoch of the flourishing of classical physics, N. A. witnessed its collapse and the beginning of the rapid growth of the new physics. Unlike many other physicists of the older generation, he did not become confused and did not proclaim the “bankruptcy of science,” but preserved to the end of his life a sound scientific optimism. This is best attested by the excellent concluding words of his brilliant ceremonial speech “The Evolution of the Atom,” which was intended for delivery on January 12, 1905, but, like the speech devoted to Maxwell, was not delivered because of political events. These are the words: “At the end of the centuries expended by human thought, we supposed that science was already working in the innermost depths of nature. It turns out that all the while we had been working only in the thin crust of the universe! Before us stands a new, immense task: the physics and chemistry of the atom—microphysics and microchemistry. And before it we stand almost as scientists in the field of electricity stood two centuries ago, knowing only that rubbed sealing wax attracts a light body. In the new field, experience is difficult because scientific technique is insufficient, and the sole path is still observation and the improvement of its methods. And if we compare electricity-as-amusement with electricity in the service of humanity, what successes should we expect in the course of the two coming centuries!

The life of the inner world of the atom will reveal to us properties and laws that may differ from those which make up the content of the old, already ancient physics.

Does there not sound over us a note of disappointment? We were already at the very truth, we had grasped it, and unexpectedly it moved away from us to a distance inestimable in its remoteness!

Yes, but we have discovered that the task of physics consists not only in describing phenomena and seeking the connections that unite them, i.e., laws. By the power of its experimental and theoretical methods it brings us nearer to the single reality lying far beyond the limits of the perceptible.

We have once more recognized the greatness and unattainable beauty of truth, and this recognition is the guarantee of the uninterrupted development and undying life of scientific thought.”

LITERATURE

The biographical data cited in the present article are borrowed from the booklet by A. I. Bachinskii:

I. A. I. Bachinskii, An Essay on the Life and Works of Nikolai Alekseevich Umov. Moscow, 1916.

II. Characterizations of N. A. Umov are contained in the Proceedings of the Moscow Society of Naturalists for 1915, which contain the following articles:

1. Brief address by the vice-president of the Society, M. A. Menzbir, on the merits of N. A. Umov before the Society (delivered at the meeting of January 10, 1915). Proceedings, pp. 1–5.
2. M. A. Menzbir, N. A. Umov as head of the learned Society. Appendix to the proceedings, pp. 23–29.
3. E. Leist, Works of N. A. Umov on terrestrial magnetism. Appendix to the proceedings, pp. 29–42.
4. S. A. Fedorov, The significance and works of Umov in the Society for the Promotion of the Advances of Experimental Sciences and Their Practical Applications named after Kh. S. Ledentsov. Appendix to the proceedings, pp. 42–49.
5. N. E. Zhukovskii, Nikolai Alekseevich Umov as a mathematician. Appendix to the proceedings, pp. 50–55.
6. A. A. Eikhenvald, On the scientific works of N. A. Umov in physics. Appendix to the proceedings, pp. 55–64.
7. A. A. Manuilov, N. A. Umov as a public figure. Appendix to the proceedings, pp. 64–66.
8. A. V. Tsinger, Nikolai Alekseevich Umov as a teacher. Appendix to the proceedings, pp. 66–75.
9. A. I. Bachinskii, Characterization of N. A. Umov as a scientist, as a thinker, and as a person. Appendix to the proceedings, pp. 76–95.

III. P. P. Lazarev, A. G. Stoletov, N. A. Umov, P. N. Lebedev. Leningrad, Scientific Chemical-Technical Publishing House, 1927.

IV. P. P. Lazarev, N. A. Umov. Published by the Moscow Society of Naturalists, Moscow, 1940.

V. A. S. Predvoditelev, Nikolai Alekseevich Umov. Scientific Notes of Moscow University. Jubilee series, issue II. Physics. Moscow, 1940, p. 81.

VI. The publication of a collected works of N. A. Umov was undertaken by the Society of Naturalists and the Ledentsov Society. However, of the planned seven volumes only one was issued (hereafter cited as “Collected Works”):

Collected Works of Professor Nikolai Alekseevich Umov. Edited and annotated by A. I. Bachinsky. Volume Three. Speeches and Articles of General Content, Moscow, 1916.

A list of N. A. Umov’s works is given in the article by A. S. Predvoditelev (V) and in the booklet by P. P. Lazarev (IV).

LITERATURE CITED IN THE TEXT

1. N. A. Umov, “Recollections of Yakov Ignat’evich Weinberg,” Collected Works, p. 74.
2. N. A. Umov, “Nikolai Alekseevich Lyubimov,” Collected Works, p. 124.
3. P. P. Lazarev, N. A. Umov. President of the Moscow Society of Naturalists, Moscow, 1940.
4. I. M. Sechenov, Autobiographical Notes, Moscow, 1907, p. 148.
5. I. I. Mechnikov, “How and Why I Settled Abroad.” (Pages of Recollections. Publishing House of the USSR Academy of Sciences, Moscow, 1946, p. 79.)
6. I. M. Sechenov, Autobiographical Notes, Moscow, 1907, p. 151.
7. A. I. Bachinsky, An Essay on the Life and Works of Nikolai Alekseevich Umov, Moscow, 1916, p. 21.
8. A. Voss, “Die Prinzipien der Rationellen Mechanik”—Encyklopädie der Mathematischen Wissenschaften, Band III, 1, S. 111, Leipzig, 1901–1908.
9. N. A. Umov, Collected Works, p. 525.
10. N. A. Umov, Collected Works, pp. 142, 143.
11. I. I. Mechnikov, “In Memory of N. A. Umov.” (Pages of Recollections, Moscow, 1946, p. 67.)
12. A. I. Bachinsky, N. A. Umov.
13. N. A. Umov, Collected Works, p. 98.
14. N. A. Umov, Collected Works, p. 184.
15. N. A. Umov, Collected Works, p. 59.
16. N. A. Umov, Collected Works, p. 390.
17. S. I. Vavilov, “V. I. Lenin and Modern Physics,” UFN, 26, 113, 1944.