Gilman S L
J Hist Behav Sci. 1979 Jul;15(3):253-62. doi: 10.1002/1520-6696(197907)15:3<253::aid-jhbs2300150306>3.0.co;2-h.
Charles Darwin's work on human and animal expression introduced this age-old problem into psychological study. Darwin's interest in the expression of the mentally ill led him to correspond with J. Crichton Browne, a young psychiatrist, who supplied him with detailed materials concerning the insane as well as photographs of them.