Ivanovsky, Dmitri Iosifovich

(b. Gdov, Russia, 9 November 1864; d. U.S.S.R., 20 June 1920)

botany, microbiology.

Ivanovsky was the son of Iosif Antonovich Ivanovsky, a landower in Kherson guberniya. He was educated at the Gymnasium of Gdov, then that of Str. Petersburg, from which he graduated as gold medalist in the spring of 1883. In August of that yearhe enrolled at St. Petersburg University in the natural science department of the physics and mathematics faculty. Among his teachers were I. M. Sechenov, N. E. Vvedensky, D. I. Mendeleev, V. V. Dokuchaev, A. N. Beketov, and A. S. Famintsyn—the leading representatives of contemporary Russian science.

In 1887 Ivanovsky and V. V. Polovtsev, a fellow student in the department of plant physiology, were commissioned to investigate the causes of a disease which had struck the tobacco plantations of the Ukraine and Bessarabia. During 1888 and 1889 they studied this disease, called “Wildfire”, and concluded that it was not infectious and arose from an abrupt change by the plants from weak to more intensive transpiration, producing light blemishes on the leaves. This work determined Ivanovsky’s future scientific interests.

On 1 Febeuary 1888, having defended his graduation thesis “O dvukh boleznyakh tabachnkykh rasteny”(”On Two Diseases of Tobacco Plants“), Ivanovsky graduated from St. Petersburg University, receiving the degree of candidate of science. On the recommendation of two professors at the university—A. N. Beketov and K. Y. Gobi—he was retained at the university in order to prepare for a teaching career. In 1891 he Joined the staff of the botanical laboratory of the Academy of Sciences.

In 1890 another disease appeared in the tobacco plantations of the Crimea, and the directors of the Department of Agriculture suggested to Ivanovsky that he study it. He left for the Crimea that summer. The first results of his investigations of mosaic disease in tobacco—O dvukh beloznyakh tabaka ( “On Two Diseases of Tobacco”)—were publish in 1892. This was the first study containing factual proof of the existence of new infectious pathogenic organisms—viruses.

To continue his scientific career Ivanovsky needed the secure position in scientific circles which could be attained only after defending a dissertation. He was for this reason compelled to turn to the study of a more specific problem. On 22January 1895 he defended his master’s dissertation , Issledovania nad spirtovym brozheniem (“An Investigation Into the Fermentation of Alcohol”), a study of the vital activity of yeast under aerobic and anaerobic conditions. He thereby earned the degree of master of botany and was subsequently assigned to give a course of lectures on the physiology of lower plants. He was further confirmed as assistant professor.

By this time Ivanovsky had married E. I. Rodionova and had a son, Nikolai. Straitened financial conditions compelled him to seek a better-paying position. In October 1896 he joined the Technological Institute as an instructor in plant anatomy and physiology, remaining there until 1901. During this period Ivanovsky returned to his early interest and became deeply involved in the study of the etiology of tobacco mosaic disease.

In August 1908 Ivanovsky moved to Warsaw: in October 1901 he had been named extraordinary professor at Warsaw University. His Mozaichnaya bolezn tabaka (“Mosaic Disease in Tobacco”), in which his investigations of the etiology of mosaic disease were summed up, was published in 1902. In 1903 he presented this book as his doctoral dissertation, defending it at Kiev. He received a D. Sc. and the title of full professor.

After defending his doctoral dissertation, Ivanovsky abandoned the study of viruses. Apparently he took this step because of both the unusual complexity of the problem itself and also the indifference and lack of understanding that most scholars showed toward his work. Neither his contemporaries nor Ivanovsky himself properly evaluated the consequences of his discovery. Either his work went unnoticed or it was simply ignored. A possible reason for this was Ivanovsky’s uncommon modesty; he never publicized his discoveries.

In Warsaw Ivanovsky studied plant photosynthesis in relation to the pigments of green leaves. The choice of this topic was the result of his interest in the chlorophyll-bearing structures (chloroplasts) in plants, a problem which had arisen during his work on mosaic disease. During these investigation Ivanovsky made a study of the adsorption spectra of chlorophyll in a living leaf and in solution and demonstrated that chlorophyll in solution is quickly destroyed by light. He also propounded the theory that the yellow pigments of a leaf—xanthophyll and carotene—act as a screen to protect the green pigment from the destructive action of blue-violet rays.

Ivanovsky’s chief fame, however, is as the discoverer of viruses. He discovered a new type of pathogenic source, which M. W. Beijerinck rediscovered in 1893 and named “virus”. He established that the sap of a diseased plant remains infectious after filtration through a Chamberland cadle, even though the bacteria visible under a microscope have been filtered out. Ivanovsky believed that this pathogenic source had the form of discrete particles—exceedingly small bacteria or bacteria spores. His point of view here differed from that of Beijerinck, who considered a virus to be contagium vivum fluidum. Ivanovsky repeated the experiments which had led Beijerinck to believed that a virus is liquid and became convinced of the rightness of his own conclusions. After following Ivanosky’s methods, Beijerinck agreed.

As the result of exhaustive histoanatomical investigations of tissue preparations from healthy and diseased plants, Ivanovsky discovered crystalline particles. He associated their presence with the onset of tobacco mosaic disease and simultaneously posed the question of a connection between the crystals that he had discovered and the minuscule living bacteria which he considered to be the pathogenic organisms of tobacco mosaic disease. Ivanovsky maintained that this pathogenic agent could exist only in the body of a living organism, that is, that it was a parasite.

Almost all the fundamental tenets of Ivanovsky’s discovery have been confirmed and developed in modern virology. The sole exception is his proposition that the source of inflection for tobacco mosaic disease was a minuscule bacterium, but Ivanovsky himself had not been fully convinced of its validity. Even during his lifetime progress was being made by filtering a contagious source through a Chamberland candle, the method he had used: dozen of rival diseases of plant and animals were discovered. Ivanovsky’s hypothesis of the existence of a direct connection between the crystals he had found and the pathogenic source was confirmed in 1935 in the work of Wendell Stanley, who obtained crystals in a test tube of the virus that causes mosaic disease in tobacco and confirmed the infectious nature of the crystals that were separated.

The parasitic nature and corpuscularity of viruses, noted by Ivanovsky, have been confirmed during the seventy-year development of virology. Ivanovsky’s view that viruses are living parasitic microorganisms is shared by many scientists, who are influenced by the consideration that viruses possess the properties of pathogenic microorganisms: specialized parasitism, a cyclical infectional process, and immunization formation.

BIBLIOGRAPHY

I. Original Works. Ivanovsky’s writings include “Iz deyatelnosti milroorganismov v pochve” (“On the Activity of Microorganisms in the Soil“), in Trudy Volnogy Ekonomicheskogo Obshchestva, 2 , no. 6 (1891), 222; O dvukh boleznyakh tabaka (“On Two Diseases of Tabacco”;St. Petersbury, 1892); Issledovania nad spirtovym brozheniem (“Investigation Into the Fermentation of Alcohol”; St. Petersbury, 1894), his master’s diss.; Mozaichnaya bolezn tabaka (“Mosaic Disease in Tobacco”; Warsaw, 1902), his doctoral diss.; and Fiziologia rasteny (“The physiology of plants”; Moscow, 1924). His writings were brought together in Izbrannye proizvedenia (“Selected Works”; Moscow, 1953).

II. Secondary Literature. See M. A. Novikova, “D. I. Ivanovsky”, in Lyudi russkoy nauki (“Men of Russian Science”; Moscow, 1963), p. 319; K. E. Ovcharov, Dmitry Iosifovich Ivanovsky (Moscow, 1952); Pamyati Dmitria Losifovicha Ivanovskogo (“In Memory of . . . Ivanovsky”; Moscow, 1952); Wendell M. Stanley, “Soviet Studies on Viruses”, in Science, 99 , no. 2564 (1944), 136-138; O prirode virusov (“On the Nature of Viruses”;Moscow, 1966); and G. M. Vayndrakh and O. M. Knyazhansky, D. I. Ivanovsky i otkrytie (“D. I. Ivanovsky and th discovery of Viruses”; Moscow, 1952).

V. Gutina

Ivanovsky, Dmitri Iosifovich(1864-1920)

Russian botanist

Dmitri Ivanovsky, in studying a disease that affects tobacco plants, paved the way for the discovery of the infectious particle known as a virus.

Ivanovsky, the son of a landowner, was born in Gdov, Russia. He attended the Gymnasium of Gdov and later graduated as a gold medalist from the Gymnasium of St. Petersburg in 1883. At the University of St. Petersburg, he enrolled in the natural science department and studied under several prominent Russian scientists. While a student, he became interested in diseases that destroy tobacco plants. He graduated in 1888 after presenting his thesis On Two Diseases of Tobacco Plants.

The following year, he was asked by the directors of the Department of Agriculture to study a new tobacco disease, called tobacco mosaic, that had afflicted plants in the Crimean region. He crushed the infected leaves, which were distinguished by their mosaic pattern, into sap and then forced the material through a Chamberland bacterial filter that was known to remove all bacteria . Despite following this procedure, the sap, when brushed on the leaves of healthy plants, was still toxic enough to cause disease. Ivanovsky's 1892 report on the tobacco mosaic disease detailed what he maintained must be an agent smaller than bacteria. It was the first study in which factual evidence was offered concerning the existence of this new kind of infectious pathogen.

Ivanovsky's work was ignored by the scientific community, and he eventually abandoned his study of this pathogen without understanding the implications of his research. The Dutch botanist, Martinus Willem Beijerinck , repeated Ivanovsky's experiments with this new pathogenic source, giving it the name filterable virus in 1898.

See also Tobacco mosaic virus (TMV); Virology