Clark, W.Mansfield (William Mansfield), 1884-1964

Clark was a biochemist who, through work on hydrogen-ion concentrations in the 1920's, helped develop and standardize the concept of pH. The common acceptance of this concept throughout the disciplines of chemistry in which the measurement and control of acidity are crucial, made a lasting impact. Later research involved studies in the oxidation-reduction potentials of organic systems. During World War II Clark served as Chairman of the Division of Chemistry and Chemical Technology, National Research Council. He was a major figure in the antimalarial drug survey and development effort undertaken by the U.S. Government. Clark taught in the Department of Physiological Chemistry, Johns Hopkins University School of Medicine, from 1927-1952. He was highly respected as a teacher and administrator. Clark moved his laboratory to the Homewoood Campus of Johns Hopkins where he continued to teach and conduct research. Clark published many articles and several books, and was the recipient of many honors and awards. He died in Baltimore on 19 January 1964.

From the description of Papers, 1903-1964. (American Philosophical Society Library). WorldCat record id: 122615970

A pioneer in the field of biochemistry, William Mansfield Clark (1884-1964) was born on August 17, 1884, the only son of Caroline Scoville Hopson (1840-1928) and James Starr Clark (1822-1914), an Episcopal minister from Tivoli Township, New York. The Clarks endowed William and his sisters Margaret, also known as "Daisy" (who later married the biologist Francis B. Sumner), and Anna with an exceptional education. William Clark was first educated first at the Trinity School, which his father had founded and administered, and after receiving a scholarship, he graduated from the Hotchkiss School in 1903. At Williams College, he studied under Leverett Mears, and received a B.A. and M.A. in 1907 and 1908 respectively, before moving to Johns Hopkins as a student of Harmon Morse. Clark received his PhD in 1910 for a dissertation entitled, "A Contribution to the Investigation of the Temperature Coefficient of Osmotic Pressure: A Redetermination of the Osmotic Pressures of Cane Sugar Solutions at 20°." While at Hopkins, Clark spent his summers at the recently established chemistry laboratory at Wood's Hole, Mass., where he served as the assistant to Carl Alsberg and later, Donald D. Van Slyke.

Clark's first professional position came as a research chemist with the Dairy Division of the Bureau of Animal Industry, United States Department of Agriculture, working under the direction of Lore A. Rogers. Before he resigned in June 1920, Clark worked on a variety of problems in dairy bacteriology, and, with his colleague Herbert A. Lubs, started studies in hydrogen-ion concentration. It was through these studies that Clark and Lubs developed and defined the concept of pH, resulting in Clark's seminal book, The Determination of Hydrogen Ions (1920, 1923, 1928). H. B. Vickery writes of the book, "[it] brought about what amounted to a revolution in bacteriological laboratories and exerted a profound influence upon all aspects of biochemistry where the measurement and control of acidity are matters of importance." 1

Remaining in the government service, Clark took a position at the Hygiene Laboratory of the U.S. Public Health Service in July, 1920, where he remained until 1927. As had been the case at the Dairy Division, Clark was given wide latitude in pursuing his research interests, which, as Clark himself wrote, increasingly focused "in measurements of oxidation-reduction potentials and their systematic formulation." 2 Clark and others undertook the reporting of their findings in a series of papers entitled, "Studies on Oxidation-Reduction," many of which were co-authored with his long-time friend and colleague Barnett Cohen. The first of these articles was published in 1923, the last, number 24, in 1956.

Clark continued his research into oxidation-reduction potentials when he accepted an appointment as DeLamar Professor of Physiological Chemistry at Johns Hopkins University School of Medicine. During his 25 years at Hopkins, from 1927 to 1952, Clark expanded his research program into ligand and metalloporphyrin systems, and he developed the concept of a "chemical continuum." In addition to laboratory research, he carried a full load of teaching and administrative responsibilities.

By all accounts, Clark was much respected as both a teacher and administrator. His desire to provide his medical students with a proper background in chemistry led him to write the enormously successful textbook, Topics in Physical Chemistry (1948, 1952). Clark clearly valued his teaching duties, writing, "[t]houghtful easement of the acquirement of knowledge is an essential part of the economics and of the aesthetics of education. It should not be regarded as less than among the tougher of intellectual jobs." 3 In addition to teaching, writing, and conducting research, Clark served on the editorial board of the Journal of Biological Chemistry from 1933 until 1952.

During World War II, Clark served as chair of the Division of Chemistry and Chemical Technology, National Research Council; was a consultant to both the Committee on Medical Research of the Office of Scientific Research and Development, and the National Defense Research Committee; was chair, and later a member, of the Committee on Biological Warfare, National Academy of Sciences; a member of the Committee on Quartermaster Problems, National Academy of Sciences; and a member of the National Academy of Sciences Council. Among the more important developments emerging from Clarks's frenzied wartime activity was the testing and development of antimalarial agents for the U.S. military. As a member of the Board for the Coordination of Malaria Studies, Clark was heavily involved in testing the most successful agent of the time, quinacrine, and in searching for new antimalarial compounds.

In 1952, Clark retired from Hopkins and was appointed DeLamar Emeritus Professor and Research Professor of Chemistry. Succeeded as the DeLamar Professor by Albert Lehninger, Clark moved from his laboratory at the medical school to one on the university's Homewood campus, where he continued his research, while maintaining a regular schedule of publication and teaching. His last book, Oxidation-Reduction Potentials of Organic Systems, appeared in 1960. Clark was working on a revision at this book, an exhaustive survey of research in the field, at the time of his death in Baltimore on January 19, 1964. He was survived by two daughters, Harriet Allen (Mrs. Everett B. Gladding) and Miriam Clark, from his marriage, on 14 September 1910, to Rose Willard Goddard (d. 1958).

Clark received a number of honors and awards during his career, including election to the National Academy of Sciences (1928) and the American Philosophical Society (1939); election as President of the Society of American Bacteriologists and of the American Society of Biological Chemists (1933 and 1934); and selection for the Cutter Lectures on Preventive Medicine (1930), as Harvey Lecturer (Fall 1933); and as Remsen Memorial Lecturer (1952). He received honorary degrees from Williams College (1935) and the University of Pennsylvania (1940), and was awarded the William H. Nichols Medal of the New York Section, American Chemical Society (1936), the Borden Award (1944); the President's Certificate of Merit (1948); the Passano Award (1957); and the Award of Merit of the Maryland Section, American Chemical Society (1963).

From the guide to the William Mansfield Clark Papers, 1903-1964, (American Philosophical Society)