L'Année Psychologique, 1898.
Lancet, June 6, 1891. Edward Smith had pointed out many years earlier that scarlet fever is most fatal in periods of increasing vitality.
Havelock Ellis, "The Bladder as a Dynamometer," American Journal of Dermatology, May, 1902.
See, e.g., summary in Internationales Centrablatt für Anthropologie, 1902, Heft 4, p. 207.