Note O — Chapter IV · LABORATORY TESTS

The productions of mind-readers, so-called, also, are based upon the perception of involuntary movements, insofar as they are not based upon pre-arranged schemes and trickery. But there we have to do principally with tactual perception, since the reader touches the hand of the subject and is guided by its tremor. Some of the expert mind-readers, however, conduct tests without touching the subject. They depend chiefly upon auditory impressions: the sound of footsteps,[13] involuntary whisperings[14] and the changes in the subject's respiration[15] and the murmuring of the spectators. To a less degree visual signs also are involved: posture and facial expression of the subject, and movements of eyes and lips.[16] Even the heat radiating from the person's body is supposed to have some influence.[17] And my own experience has taught me that surprising results may be obtained by the utilization of the movements described in the preceding chapter.

It may be that these truly microscopic movements also play some part in bringing about the success of some of the experiments in telepathy, so-called, (transference of thought from one person to another, ostensibly without any mediation of the senses known to us.) In spite of the huge mass of "experimental evidence" which has been collected, chiefly in England and in America, it appears to me that telepathy is nothing but an unproven hypothesis based upon experimental errors.