(b. Yverdon, Switzerland, 8 May 1900; d. Geneva, Switzerland, 19 June 1962)
biology, microbiology, biochemistry.
Schopfer received all of his higher education in Geneva and was awarded two licences in the natural sciences, one in 1923 and another in 1925. He won the Prix Davy for his first works, which were concerned essentially with parasitology and protozoology and dealt particularly with the molecular concentration of the juices of parasites (trematodes and cestodes). While working in the general botany laboratory, Schopfer prepared a dissertaion under the direction of Robert Chodat. In 1928 he received his doctorate from the University of Geneva after presenting his remarkable work on the sexuality of mushrooms, in which he treated a completely new problem, the comparative biochemistry of sexual reproduction. Schopfer studied abroad on several occasions, notably at the Pasteur Institute in Paris, at the biological station at Roscoff, and in Berlin (1929–1930), where he worked with Hans Kniep, an outstanding specialist in the sexuality of microorganisms.
Schopfer advanced quickly in his academic career. In 1929 he was a Privatdozent in general physiology at the Faculty of Sciences of Geneva, and in 1933 he accepted the chair of botany and general biology at the University of Bern. In the same year he became director of the university botanical institute and garden. He remained there until his death, occupying the post of dean of the Faculty of Sciences in 1941–1942 and that of rector in 1948–1949. Schopfer was president of the Swiss Society of Microbiology (1942–1943) and of the Swiss Society for the History of MNedicine and Natural Sciences (from 1946), and vice-president of the International Union of the History and Philosophy of Science. In addition he was actively involved with the scientific journals Archiv für Mikrobiologie, Enzymologia, Excerpta medica, and Internationale Zeitschirift für Vitaminforschung. Schopfer was awarded honorary doctorates by the Paris Faculty of Pharmacy (1949), the Nancy Faculty of Pharmacy (1950), the Lyons Faculty of Sciences (1950), and the Besancon Faculty of Sciences (1956). Between 1923 and 1962 he published 299 scientific works and directed twenty-two doctoral dissertations.
It was in 1927 that Schopfer, ater about twenty works devoted primarily to protozoology, published his first memoir on the secuality of the Mucoraceae. Henceforth the path of his research was clearly marked. All of Schopfer’s works and the majority of those by his students were devoted to the study of the role of organic factors controlling the growth of microorganisms. Schopfer opened the immense area of research on microbial vitamins, in which plant and animal biochemists and physiologists met.
In 1930 he inaugurated a series of experiments, which became classics, on the mold Phycomyces blakesleeanus. Following an apparently fortuitous observation, in 1931 Schopfer made a series of studies that were decisive for the new science of vitaminology. This Phycomyces cannot grow on a synthetic medium containing purified maltose, but it will grow if unpurified maltose is used. Schopfer then demonstrated that the impurity, linked to maltose, was vitamin B1. In this way it was demonstrated for the first time that an animal vitamin was necessary to the growth of a fungus. In many subsequent papers Schopfer demonstrated the roles of riboflavin, biotin, and mesoinositol—to cite only the well-known compounds—in the growth of microorganisms. To the classic distinction between autotrophic and heterotrophic individuals, Schopfer added that between auxoautotrophic species, capable o producing the vitamins necessary for their growth, and the auxoheterotrophic species incapable of synthesizing them. He devoted a series of studies to what he called artificial symbiosis. He showed, for example, that certain mush rooms that need only one of the constituents of the vitamin B complex, such as Rhodotorula rubra, the growth of which requires pyrimidine, and Mucor ramanninanus, which needs thiazole, are able to live in association without these substances.
But Schopfer employed mainly Phycomyces as a biological test of the quantitative dosage of vitamin B1, and it permitted him to determine precisely a group of questions concerning the biosynthesis of vitamins, their role in the soil, and their importance for the higher organisms. Schopfer also concentrated on the mechanisms of action of these vitamins and demonstrated the effects of structurally similar substances that behave as antagonists, which he called antivitamins. All the investigation of vitamins conducted by Schopfer and his students were joined with those of other scientists in a remarkable work published in 1939, then reworked and completed in English as Plants and Vitamins (1943). Schopfer also conducted research on nitrogen metabolism, the in vitro culture of plant organs, graftings, and morphogenesis.
In addition to research, Schopfer was greatly interested in the history of science; and his studies in the history of biology are valuable for the abundance of their documentation and for his critical analysis of the facts discussed. Among his writings in this field are “L’histoire des théories relatives à la génération au 18me et au 19me siècle” (1944), La recherche de l’uniteé en biologie (1948), and a study of the work of Jules Raulin (1949). He also produced Situation de la biologie dans le système des sciences (1951), L’évolution de la méthode en biologie du point de vue de l’historie des sciences (1952), and an edition of the letters of Leeuwenhoek (1955).
I. Original Works. A list of 299 scientific papers by Schopfer was published in Mitteilungen der Naturforschenden Gesellschaft in Bern, 20 (1964), 86–102. They include “Vitamine und Wachstumsfaktoren beiden Mikroorganismen, mit besonderer Berücksichtigung des Vitamins B1,” in Ergebnisse der Biologie, 16 (1939), 1–172; revised and enlarged as Plants and Vitamins, N. N. Noecker, trans. (Waltham, Mass., 1943: 2nd ed., 1949); “Les vitamines, facters de croissance pour les microorganismes,” in Schweizerische Zeitschrift für Pathologie und Bakteriologie, 7 (1944), 303–345; “L’histoire des théories relatives à la génération au 18 me et au 19me siècle.” in Actes de la Société helvétique des sciences naturelles (1944), 192–193; “Les tests micro-biologiques pour la détermination des vitamines,” in Experientia. 1 (1945), 183–194, 219–229; La recherche de l’unité en biologie (Bern, 1948): Les répercussions hors de France de l’oeuvre de Jules Raulin relative au zinc (Lyons, 1948); “Remarque bibliographique sur l’histoire du terme Cambium,” in Archives internationales d’histoire des sciences, 28 (1949), 457–458; “Situation de la biologie dans le systeme des sciences; les relations de la biologie avec les autres sciences,” in Actes de la Société helvétique des sciences naturelles (1951), 68–80; “Le méso-inositol en biologie,” in Bulletin de la Société de chimie biologique, 83 (1951), 1113–1146; “L’évolution de la méthode en biologie du point de vue de l’histoire des sciences,” in Actes scientifiques et industrielles Herrman, 8 (1952), 117–125; “Les cultures d’organes et leurs applications en physiologie végétale,” in Actes de la Société helvétique des sciences naturelles (1952), 61–73; “La botanique et le bien-être humain,” in Actes du 8me congrés international botanique, 1954 (1959), 53–57; and “Recherches sur le role du méso-inositol dans la biologie cellulaire de Schizosaccharomyces pombe Lindner,” in Archiv fur Mikrobiologie, 44 (1962), 113–151, his last work.
II. Secondary Literature. See K. H. Erismann, “William-Henri Schopfer (1900–1962),” in Verhandlungen der Schweizerischen naturforschenden Gesellschaft, 142 , pt. 1 (1962), 252–258; and “Die wissenschaftlichen Arbeiten von Prof. Dr. W.-H. Schopfer: Chronologisch geordner von 1923 bis 1962,” in Mitteilungen der Naturforschenden Gesellschaft in Bern, n.s. 20 (1963), 86–102; and A. Tronchet, “Rapport sur l’attribution du Dr. H. C. de l’Université de Besançon à M. le professeur Schopfer,” in Annales scientifiques de l’Université de Besançon, 2nd ser., 2 (1958), 1–4.