Snow on cholera: being a reprint of two papers by John Snow, M.D., together with a Biographical Memoir by B.W. Richardson, M.D., and an Introduction by Wade Hampton Frost, M.D., Professor of Epidemiology, The Johns Hopkins School of Hygiene and Public Health. New York: The Commonwealth Fund; London: Humphrey Milford, Oxford University Press. 1936. pp. 191. Price $2.50.