^ "Glossary of Key Words Frequently Used in Parapsychology" Archived 2010-12-24 at the Wayback Machine, Parapsychological Association website. "Materialization: A phenomenon of physical mediumship in which living entities or inanimate objects are caused to take form, sometimes from ectoplasm." Retrieved January 24, 2006 "Medium – Definition". Dictionary.com. Retrieved 23 March 2007.
^ LeCron, Leslie; Bordeaux, Jean (1970). Hypnotism Today. Wilshire Book Co. p. 278. ISBN 0-87980-081-X. When in a trance ... the medium seems to come under the control of another personality, purportedly the spirit of a departed soul, and a genuine medium undoubtedly believes the 'control' to be a spirit entity ... In the trance, the medium often enters a cataleptic state marked by extreme rigidity. The control then takes over, the voice may change completely ... and the supposed spirit answers the questions of the sitter, telling of things 'on the other plane' and gives messages from those who have 'passed over.' https://drive.google.com/file/d/1jaiz1mTECKiiESpwX8al362NU5Rjk2JP/view?usp=sharing
On 4 February 1922, Harry Price with James Seymour, Eric Dingwall and William S. Marriott had proven the spirit photographer William Hope was a fraud during tests at the British College of Psychic Science. Price wrote in his SPR report "William Hope has been found guilty of deliberately substituting his own plates for those of a sitter... It implies that the medium brings to the sitting a duplicate slide and faked plates for fraudulent purposes." The medium Kathleen Goligher was investigated by the physicist Edmund Edward Fournier d'Albe. On July 22, 1921 in a séance he observed Goligher holding the table up with her foot. He also discovered that her ectoplasm was made of muslin. During a séance d'Albe observed white muslin between Goligher's feet.
In the late 1920s and early 1930s there were around one quarter of a million practising Spiritualists and some two thousand Spiritualist societies in the UK in addition to flourishing microcultures of platform mediumship and 'home circles'. Spiritualism continues to be practised, primarily through various denominational Spiritualist churches in the United States, Canada, Australia and the United Kingdom. In the United Kingdom, over 340 Spiritualist churches and centres open their doors to the public and free demonstrations of mediumship are regularly performed.