Nikolai Semenovich Kurnakov

Born Nov. 24 (Dec. 6), 1860, in Nolinsk, in present-day Kirov Oblast; died Mar. 19, 1941, in Barvikha, in present-day Odintsovo Raion, Moscow Oblast. Soviet physical chemist. Academician (1913) and Honored Scientist of the RSFSR (1940).

Kurnakov began teaching at the St. Petersburg Mining Institute after his graduation there in 1882. In 1893 he became a professor. He was a professor at the St. Petersburg (Leningrad) Polytechnical Institute from 1902 to 1930.

Kurnakov was one of the organizers and a deputy chairman of the Commission for the Study of the Natural Resources of Russia of the Russian Academy of Sciences (1915–26). He was the director of various research institutes of the Academy of Sciences of the USSR, including the Institute of Physicochemical Analysis (from 1918), organized upon his own initiative; the General Chemistry Laboratory (from 1920); the Institute for the Study of Platinum and the Noble Metals (from 1922); and the Institute of General and Inorganic Chemistry, organized through the consolidation, in 1934, of the three former institutions (known since 1944 as the N. S. Kurnakov Institute of General and Inorganic Chemistry). Kurnakov was director of the State Institute for Applied Chemistry from 1919 to 1927 and chairman of the Chemical Association of the Academy of Sciences of the USSR from 1930 to 1934.

Kurnakov’s dissertation, On Complex Metallic Bases (1893), summarized the results of his study of the chemistry of complex compounds. His invention of an automatic pyrometer in 1903 proved to be a major advance in the technique of thermal analysis. Together with S. F. Zhemchuzhnyi, Kurnakov established the relationships between composition and properties in binary systems, including electric conductivity (1906), solidity (1908), and escape pressure (1908–13).

In a study of the viscosity of binary liquid mixtures, Kurnakov and Zhemchuzhnyi found that the formation of a given compound in a homogeneous medium was expressed by a singular point on a composition-properties diagram, making it possible to distinguish between chemical compounds of constant and variable composition. Kurnakov and his associates discovered a number of berthollides in metallic systems, as well as the theoretically important case of the formation of daltonides in the transitions of solid solutions of gold and copper (1914). These works were the basis for the development of physicochemical analysis.

Kurnakov’s investigations facilitated the initiation and development of new areas of production in the USSR, including the refining of platinum metals, the smelting of aluminum and magnesium, the production of light and high-resistance alloys, the potassium industry, and the manufacture of mineral fertilizers.

Kurnakov trained a large number of chemists and metallurgists. He was awarded the D. I. Mendeleev Great Prize in 1924, the V. I. Lenin Prize in 1928, the State Prize of the USSR in 1941, and the Order of the Red Banner of Labor.