Early clairvoyance experiments were reported in 1884 by Charles Richet. Playing cards were enclosed in envelopes and a subject put under hypnosis attempted to identify them. The subject was reported to have been successful in a series of 133 trials but the results dropped to chance level when performed before a group of scientists in Cambridge. J. M. Peirce and E. C. Pickering reported a similar experiment in which they tested 36 subjects over 23,384 trials which did not obtain above chance scores.