Many years thereafter, in 1888, Margaret Fox (Mrs. Kane) and Katie Fox (Mrs. Jencken) publicly confessed that the raps to which they as children gave rise were produced by dislocation of the toes; and one of them added to their confession a demonstration of how this was done. It is unfortunate alike that the character of the confessers leaves much to be desired, that the confession was both belated and made under sensational surroundings, and that the sinners have no better excuse to offer for their long silence than that the movement was started when they were too young to appreciate what was being done, and that when they realized the fraud which they were fostering and the success with which they were meeting, it was too late or too difficult to retract. None the less, these circumstances do not destroy the interest in tracing the evidence of deception and the presence of a moral taint to the very starting-point of one of the most widespread delusions of modern times. The psychological aspect of the phenomena of Spiritualism may be presented in a consideration of these questions: How is it that the manifestations produced in evidence of spirit-control carry conviction? What is the origin of this mass of testimony in favor of spiritualistic marvels? Whence this general tendency to believe in the reality of spirit-influence as thus manifested? For the purposes of these inquiries it will be profitable to consider a few typical manifestations and to observe their true inwardness. Among the most influential mediums was Henry Slade; through him many were converted to Spiritualism, including the famous Zöllner coterie, for whom he gave a spiritual demonstration of the reality of the fourth dimension of space. After all the prominence which has been given to the Zöllner sittings and the importance attached to them by reason of the eminence of the participants, it is somewhat unexpected to read in the report of a reliable observer who interviewed Zöllner's associates, that "of the four eminent men whose names have made famous the investigation, there is reason to believe one, _Zöllner_, was of unsound mind at the time, and anxious for an experimental demonstration of an already accepted hypothesis (the fourth dimension of space); another, _Fechner_, was partly blind, and believed because of Zöllner's observations; a third, _Scheibner_, was also afflicted with defective vision, and not entirely satisfied in his own mind as to the phenomena; and a fourth, _Weber_, was advanced in age, and did not even recognize the disabilities of his associates." None knew anything about conjuring, and, deservedly honored as these men were in their own specialties, they were certainly not fitted to compete with a professional like Slade. One of Slade's standard performances was the production of communications on a slate held beneath a table, in answer to questions asked by his sitters verbally or in writing, the writing in some cases being concealed in folded slips