(b. Asheda, Sweden, 4 April 1867; d. Boston, Massachusetts, 25 October 1934)
Folin was the son of Nils Magnus Folin, a tanner, and Eva Olson Folin, the village midwife. At the age of fifteen he immigrated to the United States to join his brother Axel, who was living in the lumbering town of Stillwater, Minnesota. He worked for a time on various farms in the region and in 1888 moved to Minneapolis to enter the University of Minnesota, from which he received his B.S. degree in 1892. He then studied with Stieglitz at the University of Chicago, completing a thesis on urethanes in 1896. Since he wished to study biochemistry, he spent two years in Europe, working with Albrecht Kossel at Marburg, Olof Hammarsten at Uppsala, and E. L. Salkowski in Berlin before returning to take his Ph.D. from Chicago in 1898. He was appointed assistant professor of analytical chemistry at the University of West Virginia in 1899, and in the same year he married Laura Grant. He was survived by a son and a daughter. In 1900 Folin took charge of the first laboratory for biochemical research to be established in a hospital, the McLean Hospital for the Insane at Waverley, Massachusetts. In 1907 he was appointed to the first chair of biochemistry in the Harvard Medical School, and there he remained for the rest of his life.
When he began work at the McLean Hospital, Folin decided to seek a method for detecting differences in metabolism between psychotic and normal individuals. He realized that urinary constituents reflect the metabolic state of the body and therefore began to study quantitative methods of urinalysis. He devoted particular attention to nitrogenous compounds and worked out colorimetric methods for their determination. Although his original hopes of obtaining results of psychiatric value were not realized, he grew more and more interested in developing analytical methods for biochemical research, and this field became his specialty. He soon recognized that analysis of blood constituents offered a better guide to metabolic reactions than did urinalysis, and most of his later work concerned blood analysis. He summed up much of this work in his classic paper on microchemical methods of blood analysis, which he published with Hsien Wu in 1919. His work with nitrogenous compounds led him to the concept of endogenous and exogenous metabolism which, although later greatly modified, was very fruitful at the time of its proposal. He established the fact that amino acids are absorbed from the intestine in free from rather than as proteins. His colorimetric methods made possible much of later biochemical analysis.
Folin was active in the organization and administration of various biochemical societies and in aiding the publication of papers on biochemical research. Most of his work appeared in the Journal of Biological Chemistry, of which he was a leading supporter. In the latter part of his life he received many honorary degrees, from both European and American universities. At the time of his death he was recognized as the leading authority on biochemical analysis.
I. Original Works. Most of Folin’s early papers appeared in Hoppe-Seyler’s Zeitschrift für physiologische Chemie and his later work in the Journal of Biological Chemistry. The paper “A System of Blood Analysis,” written with Hsien Wu, appeared in Journal of Biological Chemistry, 38 (1919), 81–110.
II. Secondary Literature. Biographical appreciations of Folin appear in Science (New York), 81 (1935), 35–38; and in Medical Journal of Australia, 1 (1935), 69.
Henry M. Leicester