John Gregory Bourke - Scatalogic Rites of all Nations (1891)
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The title page notes "Not for General Perusal" and considering that the book is about exactly what the title says that warning is still true. Its seriousness may be judged by the fact that Freud wrote an introduction to a 1913 edition (which is included in his Complete Psychological Works) and the American Anthropological Society reprinted it in 1934. The list of people who contributed information include Franz Boas, Havelock Ellis, James Frazer and Andrew Lang. Chapters include "Obscene Survivals in the Games of English Rustics", "The Onion Adored by Egyptians", "Poisonous Mushrooms Used in Ur-Orgies" and "The Mushroom in Connection with the Fairies" along with numerous others that I don't feel like quoting.
Bourke was a Medal of Honor recipient who served as a cavalryman in the New Mexico territory. He wrote several books about American Indians