The psychical researcher Hereward Carrington exposed fraudulent mediums' tricks, such as those used in slate-writing, table-turning, trumpet mediumship, materializations, sealed-letter reading, and spirit photography.[29] The skeptic Joseph McCabe, in his book Is Spiritualism Based on Fraud? (1920), documented many fraudulent mediums and their tricks.[30]
In 1936, the psychical researcher Nandor Fodor tested the Hungarian apport medium Lajos Pap in London and during the séance a dead snake appeared. Pap was searched and was found to be wearing a device under his robe, where he had hidden the snake.[157] A photograph taken at a séance in 1937 in London shows the medium Colin Evans "levitating" in mid air. He claimed that spirits had lifted him. Evans was later discovered to be a fraud as a cord leading from a device in his hand has indicated that it was himself who triggered the flash-photograph and that all he had done was jump from his chair into the air and pretend he had levitated.[158]
As soon as Thomas John set foot in the mbg office a few weeks ago, we knew he was the real deal. The skeptics among us walked away as converts, having communicated with their ancestors through Thomas in ways they never dreamed possible. Here, the highly sought-after medium and intuitive whose celebrity clientele includes Jennifer Lopez and Courteney Cox shares his top insights from the other side.
The exposures of fraudulent activity led to a rapid decline in ectoplasm and materialization séances.[199] Investigator Joe Nickell has written that modern self-proclaimed mediums like John Edward, Sylvia Browne, Rosemary Altea and James Van Praagh are avoiding the Victorian tradition of dark rooms, spirit handwriting and flying tambourines as these methods risk exposure. They instead use "mental mediumship" tactics like cold reading or gleaning information from sitters before hand (hot reading). Group readings also improve hits by making general statements with conviction, which will fit at least one person in the audience. Shows are carefully edited before airing to show only what appears to be hits and removing anything that does not reflect well on the medium.[200]