Brotherhood of Mediums
From Kook Science
The Brotherhood of Mediums was a supposed union of professional mediums, formed for "mutual protection and the exchange of methods and information,"[I] which included the distribution of biographical details about regular clients for use in fraudulent séances and other psychic readings, a system sometimes referred to as the Medium's Blue Book. It is uncertain that such a group existed in as any kind of truly organised, secret fraternity, and more likely served as a convenient label that could be affixed to any number of informal arrangements between workers in the psychic market.
- Irwin, Will (1907-09-21), "The Medium Game: Behind the Scenes with Spiritualism, II. Psychics and Clairvoyants", Collier's (New York: P. F. Collier & Son): 17-19, https://books.google.com/books?id=4QOhBX5bSREC&pg=RA25-PA17