The _Report_ consists of the reports of the séances of six experimental subcommittees, minutes of the examination before the General Committee of spiritualist witnesses, letters on spiritualism from a great number of literary and scientific persons, and communications in the shape of experiences and speculative essays on spiritualism by some of its principal adherents. Subcommittee No. 1 (_Rep._, p. 9) declares itself to have "established conclusively" "the movements of heavy substances without contact or material connection of any kind between such substances and the body of any person present." This is confirmed by Subcommittee No. 2, and embodied in the general report. Amongst a great mass of well-attested phenomena, I select the following: "Thirteen witnesses state that they have seen heavy bodies, in some instances men, rise slowly in the air, and remain there without visible or tangible support." "Fourteen witnesses testify to having seen hands of figures not appertaining to any human being, but lifelike in appearance and mobility, which they have sometimes touched and even grasped." "Eight witnesses state that they have received precise information through rappings, writings, and in other ways, the accuracy of which was unknown at the time to themselves or to any persons present, and which, on subsequent inquiry, was found to be correct." Many of these experimental séances took place without the presence of any professional mediums. Subcommittees 1 and 2 declare that they have never used them, and these were particularly fertile in instances of independent movement, No. 1 having witnessed no less than fifty such motions. There is absolutely no room for a suspicion of trickery, neither is it more rational to suppose that the phenomena had no objective existence, but were the mere phantasms of the excited imagination of the company; for the witnesses testify that they were in no such state of excitement, and their recorded conversation and behavior are incompatible with any such supposition. Again, such excitement acts spasmodically and irregularly; but, as a rule, the phenomena are seen by all equally. In the few cases in which individuals have manifested abnormal excitement, the séances have been frustrated. Subcommittee No. 2 sent for a neighbor to witness the phenomena when in full operation, and they presented precisely the same aspect to him as they did to the members of the séance. There remains, then, a large number of objective phenomena of the kind mentioned which have to be accounted for. Three hypotheses have been advocated with more or less success, which I shall proceed to consider in order.