Kliment Timiriazev

Timiriazev, Kliment Arkad’evich


Born May 22 (June 3), 1843, in St. Petersburg; died Apr. 28, 1920, in Moscow. Naturalist-Darwinist; one of the founders of the Russian school of plant physiology. Corresponding member of the St. Petersburg Academy of Sciences (1890).

In 1865, Timiriazev graduated as an external student from the University of St. Petersburg. (He had been expelled from the university in 1861 because he attended student meetings.) Timiriazev’s world outlook was greatly influenced by the materialist philosophical views of A. I. Herzen, N. G. Chernyshevskii, and other revolutionary democrats. Timiriazev was also influenced by the writings of D. Mendeleev, V. O. Kovalevskii, A. O. Kovalevskii, E. I. Metchnikoff, and—especially—I. M. Sechenov and C. Darwin. While still a student, Timiriazev published a number of articles on social and political subjects and on Darwinism; these included “Garibaldi on Caprera” (1862), “Starvation in Lancashire” (1863), and “Darwin’s Book, Its Critics and Commentators” (1864).

In 1868, at the suggestion of A. N. Beketov, the University of St. Petersburg sent Timiriazev abroad—to Germany and France—for two years to prepare for a career as a professor. He worked in the laboratories of leading physicists, chemists, physiologists, and botanists, including G. Kirchhoff, H. von Helm-holtz, R. von Bunsen, P. Berthelot, J. Boussingault, C. Bernard, and W. Hofmeister. Timiriazev regarded Boussingault as his mentor, and clearly it was this scholar who had the greatest influence on him.

From 1870 to 1892, Timiriazev taught at the Petrovskoe Farming and Forestry Academy (now the K. A. Timiriazev Moscow Agricultural Academy). In 1871 he defended his master’s thesis, “Spectral Analysis of Chlorophyll,” and was appointed as an extraordinary professor at the academy. He was made a full professor in 1875, after defending his doctoral dissertation, “The Assimilation of Light by Plants.”

In 1878, Timiriazev became a professor at Moscow University. In 1902 he was appointed an honorary full professor. Timiriazev left the university in 1911 in protest against the actions of the reactionary minister of education, Kasso. In 1917, after the Great October Socialist Revolution, Timiriazev was given back his post at Moscow University, but he was unable to return to his department because of ill health. He devoted the last ten years of his life to publicist writing.

Timiriazev’s research was primarily concerned with photosynthesis. He developed special techniques and apparatus for his investigations. In determining the relationship between photosynthesis and the intensity and spectral composition of light, he discovered that plants assimilate carbon from atmospheric carbon dioxide through the energy of sunlight, mainly the red and blue rays, which are most fully absorbed by chlorophyll. The first to state that chlorophyll participates in photosynthesis both physically and chemically, Timiriazev anticipated current thinking on the subject. Timiriazev discovered the phenomenon of light saturation in photosynthesis (“The Relationship Between the Assimilation of Carbon and Light Intensity,” 1889). He showed that at low intensities of light the rate of photosynthesis is proportional to the energy absorbed, but as light intensities increase the rate gradually becomes stable and no longer changes. Timiriazev demonstrated experimentally that the law of conservation of energy and the first law of photochemistry can be applied to photosynthesis.

In his lecture on the cosmic role of plants delivered before the Royal Society of London (1903; Russian translation, 1904), Timiriazev summed up his many years of research on photosynthesis. He explained the role of photosynthesis in green plants as the primary source of the organic matter and stored energy needed for the life processes of all organisms. His discovery of the energy principle underlying photosynthesis was a major contribution to the study of the relationship between animate and inanimate matter in the cycle of matter and energy in nature.

Timiriazev viewed plant physiology and agricultural chemistry as the bases of rational agriculture. In 1867, on the recommendation of Mendeleev, Timiriazev was appointed to manage the experimental field in the village of Ren’evka, Simbirsk Province. Funds for the project were supplied by the Free Economic Society. Timiriazev ran experiments on the field to study the effect of mineral fertilizers on yields. In 1872 he proposed that a greenhouse, the first in Russia, be built on land owned by the Petrovskoe Agricultural Academy. In 1896 he organized a demonstration experiment station with a greenhouse at the All-Russian Exhibition in Nizhny Novgorod. In the lecture “Plant Physiology as the Basis of Rational Agriculture” (1897), Timiriazev showed the usefulness of mineral fertilizers. In 1892, in connection with the crop failure caused by the 1891 drought, Timiriazev read the lecture “Control of Drought by Plants” (published 1893), in which he summarized the available data on water conditions and on the drought resistance of plants and recommended practical measures to reduce the harm done to agriculture by drought.

Timiriazev was one of the first to promote Darwinism in Russia. He regarded Darwin’s theory of evolution as the greatest achievement of 19th-century science and as corroboration of the materialist approach in biology. In the books A Brief Essay on Darwin’s Theory (1865) and Charles Darwin and His Theory (1882; 15th ed., 1941), Timiriazev summarized his articles on Darwinism that had appeared in the journal Otechestvennye zapiski (Notes of the Fatherland) since 1864. Between 1908 and 1910, in connection with the 50th anniversary of Darwin’s On the Origin of Species, Timiriazev published a series of articles in which he promoted Darwinism and defended it against the attacks of conservative scientists and clergymen. In the series of lectures given under the general title “The Historical Method in Biology” (published 1922), he explained Darwin’s theory, identifying problems of morphology and physiology and suggesting ways to solve them through study of the historical process of the origin of form and function. Timiriazev also elucidated the evolution of functions in plants from the standpoint of Darwinism, primarily the law of natural selection. Specifically, he explained the evolution of photosynthesis and of the universal distribution of chlorophyll in autotrophic plants.

Timiriazev repeatedly emphasized that the recent forms of organisms are the result of a long process of adaptive evolution. The stamp of adaptation to environmental conditions and the stamp of all preceding evolution characterizes every extant species. Timiriazev believed, therefore, that the historical method—that is, a systematic evolutionary approach to the study of organisms—is essential in order to understand the laws of biology and to understand and control the various manifestations of life. He wrote: “Neither morphology, with its effective comparative method, nor physiology, with its even more productive experimental method, can cover the entire field of biology or deal exhaustively with its problems. Both need to be supplemented by the historical method” (Soch., vol. 6, 1939, p. 61).

Timiriazev is also remembered for his important role in the popularization of science. He wrote: “At the very beginning of my career I established two parallel goals for myself: to work for science and to write for the people, that is, in a popular manner” (ibid., vol. 9, pp. 13–14). Timiriazev regarded the popularization of scientific knowledge as a means of uniting science and democracy. A classical example of his dedication to the popularization of science is his book The Life of Plants (1878), which has appeared in dozens of Russian and foreign editions. The combination of thorough analysis of current problems in the natural sciences with a simple and attractive style also characterizes many of Timiriazev’s other works, including Results of a Century of Research on Plant Physiology (1901), Highlights of the History of Biology in the 19th Century (1907), The Awakening of the Natural Sciences in the Third Quarter of the Century (1907, reissued in 1920 as The Development of the Natural Sciences in Russia in the 1860’s), Advances in Botany in the 20th Century (1917, reissued in 1920 as The Most Important Advances in Botany in the Early 20th Century), and Science: A Historical Sketch of the Natural Sciences During the Last Three Centuries, 1620–1920 (1920). The numerous biographical sketches, reminiscences, and obituaries of leading scientists (Darwin, Pasteur) written by Timiriazev are as firmly grounded and accessible as his scientific writings.

Timiriazev supported the idea that science plays a major role in the struggle for peace. In 1917 he wrote, “Science and democracy by their very nature are hostile to war” (ibid., p. 252).

Timiriazev was among the first major Russian scientists to welcome the Great October Socialist Revolution. In 1920 he published the collection of articles Science and Democracy, on which Lenin, in his letter to Timiriazev, commented, “I was simply delighted to read your remarks against the bourgeoisie and for Soviet power” (Poln. sobr. soch., 5th ed., vol. 51, p. 185). The 75-year-old Timiriazev, despite his serious illness, was active in the work of the People’s Commissariat for Education of the RSFSR and of the Socialist (later Communist) Academy of Social Sciences. He was elected a member of the academy in 1918 and a deputy of the Moscow City Soviet of Workers’ Deputies in 1920.

Shortly before his death, Timiriazev said, “The Bolsheviks, adherents of Leninism—I believe and am convinced—are working for the happiness of the people and will bring them to happiness” (Soch., vol 1, 1937, p. 160).

A monument to Timiriazev has been erected in Moscow, and his flat has become a museum. The Moscow Agricultural Academy and the Institute of Plant Physiology of the Academy of Sciences of the USSR have been named in Timiriazev’s honor. A raion in Moscow and streets in many Soviet cities also bear his name. The Academy of Sciences of the USSR awards the Timiriazev Prize once every three years for the best work in plant physiology, and it annually sponsors Timiriazev lectures.

Timiriazev was a fellow of the Royal Society of London (1911); an honorary doctor of science at universities in Glasgow (1901), Cambridge (1909), and Geneva (1909); a corresponding member of the Edinburgh Botanical Society (1911); and an honorary member of many Russian universities and scientific societies.


Sochineniia, vols. 1–10. Moscow, 1937–40.
Izbr. soch., vols. 1–4. Moscow, 1948–49.
Izbr. soch., vols. 1–2. Moscow, 1957.
Nauka i demokratiia (collection of articles). Moscow, 1963.


Komarov, V. L., N. A. Maksimov, and B. G. Kuznetsov. Kliment Arkad’evich Timiriazev. Moscow, 1945. (Contains a bibliography of Timiriazev’s works that appeared before 1945.)
Novikov, S. A. K. A. Timiriazev (1843–1920). Edited by A. K. Timiriazev. Moscow, 1948.
Tsetlin, L. S. K. A. Timiriazev, 2nd ed. Moscow, 1952.
Korchagin, A. I. K. A. Timiriazev: Zhizn’ i tvorchestvo, 3rd ed. Moscow, 1957.
Chailakhian, M. Kh. K. A. Timiriazev—uchenyi, borets, myslitel’. Moscow, 1960.
Senchenkova, E. M. K. A. Timiriazev i uchenie o fotosinteze. Moscow, 1961.
Genkel’, P. A. “K 125-letiu so dnia rozhdeniia K. A. Timiriazeva.” Fiziologiia rastenii, 1968, vol. 15, fasc. 3.