The mediums ranged from 15 to 47 years of automatic writing experience, performing up to 18 psychographies per month. All were right-handed, in good mental health, and not currently using any psychiatric drugs. All reported that during the study they were able to reach their usual trance-like state during the psychography task and were in their regular state of consciousness during the control task.
In September 1878 the British medium Charles Williams and his fellow-medium at the time, A. Rita, were detected in trickery at Amsterdam. During the séance a materialized spirit was seized and found to be Rita and a bottle of phosphorus oil, muslin and a false beard were found amongst the two mediums. In 1882 C. E. Wood was exposed in a séance in Peterborough. Her Indian spirit control "Pocka" was found to be the medium on her knees, covered in muslin.