Terminology
The phrase "feminine soul enclosed in a male body" (anima muliebris in corpore virili inclusa) was introduced in 1868 by Karl-Heinrich Ulrichs, not to describe male-to-female transsexuals, none of whom existed yet as such, but to describe a type of gay men who self-identified as feminine. Major sexologists in the 19th century picked up the idea that a homosexual was "a female soul in a male body, a condition deriving from an error in embryonic differentiation." Those homosexuals who felt themselves to be female were categorized, "in the interest of scientific precision," as "urnings" (now known as uranians).
Read more about this topic: Feminine Essence Concept Of Transsexuality