In 1910 at a séance in Grenoble, France the apport medium Charles Bailey produced two live birds in the séance room. Bailey was unaware that the dealer he had bought the birds from was present in the séance and he was exposed as a fraud.[114] The psychical researcher Eric Dingwall observed the medium Bert Reese in New York and claimed to have discovered his billet reading tricks.[115] The most detailed account at exposing his tricks (with diagrams) was by the magician Theodore Annemann.[116]
A series of mediumistic séances known as the Scole Experiment took place between 1993 and 1998 in the presence of the researchers David Fontana, Arthur Ellison and Montague Keen. This has produced photographs, audio recordings and physical objects which appeared in the dark séance room (known as apports).[188] A criticism of the experiment was that it was flawed because it did not rule out the possibility of fraud. The skeptical investigator Brian Dunning wrote the Scole experiments fail in many ways. The séances were held in the basement of two of the mediums, only total darkness was allowed with no night vision apparatus as it might "frighten the spirits away". The box containing the film was not examined and could easily have been accessible to fraud. And finally, even though many years have passed, there has been no follow-up, no further research by any credible agency or published accounts.[188]
Senses used by mental mediums are sometimes defined differently from in other paranormal fields. A medium is said to have psychic abilities but not all psychics function as mediums. The term clairvoyance, for instance, may include seeing spirit and visions instilled by the spirit world. The Parapsychological Association defines "clairvoyance" as information derived directly from an external physical source.[37]