Henry Havelock Ellis (2 February 1859 - 8 July 1939) was a British physician, eugenicist, author, liberal intellectual and social reformer who researched the sexuality of humans. He co-wrote the first medical textbook in English on homosexuality in 1897, and also produced books on a range of sexual practices and inclinations, as well as on transsexual psychology. He developed the theories of narcissism and autoeroticism, later accepted by psychoanalysis. Ellis was among the pioneering investigators of psychedelic drugs and the author of one of the earliest documented reports to the public of an experience with mescaline, which he conducted on himself in 1896. He encouraged genetics and served as one of the 16 vice-presidents of the Eugenics Association from 1909 to 1912. Ellis, who is son of Edward Peppen Ellis and Susannah Mary Wheatley, was raised in Croydon, England Surrey (now part of Greater London). His father was a sea captain and an Anglican, whereas his mom was the daughter of a sea captain who had numerous additional family who lived on or near the sea. When he was seven his father brought him on one of his journeys, during which they called at Sydney, Australia; Callao, Peru; and Antwerp, Belgium. After his return, Ellis attended the French and German College near Wimbledon, and thereafter attended a school in Mitcham.