however, was excluded, since on that afternoon the air was perfectly still. Several times during the séance Mr. Slade fell into convulsions and asked me, who sat beside him, whether I felt anything, which, however, was not the case. The other persons present occasionally felt thrusts against their legs, and the tablet, which they held in their hands under the table, was violently pushed away; with myself this did not take place. At the end of the sitting we arose, Mr. Slade laid his hands upon ours and first lifted the table several inches from the floor, then letting it suddenly fall again; it was clearly perceptible that the table was raised by a central force from beneath. With our wish to perform some of the experiments in the presence of an observer standing outside the circle Mr. Slade could not comply. He said that under that condition the spirits did not obey him; he was, moreover, a perfectly passive observer, and must accommodate himself to the conditions which he had accidentally discovered to be favorable for his experiments. Incidentally he gave us intelligence concerning our own mediumistic endowments; me he declared to be a medium "of a strong power." How he came to this knowledge he did not communicate. To myself, as I will not neglect to mention, never in my life has anything appeared or happened which might warrant such a diagnosis.
If you ask me now whether I am in a condition to express a conjecture as to how these experiments were performed, I answer, No. At the same time, however, I must state that phenomena of this sort lie entirely outside the domain of the special training which I have acquired during my scientific career. It is known to every naturalist that one is able to judge an experiment correctly only when one has one's self experimented in a similar direction, and thus has an insight into the conditions of the origin of the phenomena. If I were really a medium "of a strong power," as Mr. Slade asserts, I should perhaps be in a better condition to answer your question; but, since this is not the case, you will certainly find it justifiable, if I do not go into hypotheses as to how the phenomena produced by Mr. Slade were brought about. What was surprising to me in the matter, however, and what will also surprise you, is that Mr. Slade also refused to give any information of this kind. He is a medium, he is an experimenter, and he must therefore know under what conditions the phenomena have their origin. He asserts that he knows nothing of them, but that his relation is a perfectly passive one. The latter, however, is plainly untrue, since the phenomena generally appear only in the séances held by him, and also, as a rule, in the order in which he wishes to produce them.
But, although we can not determine how Mr. Slade performs his experiments, I agree with you that we still may not in this case pass the field by as one foreign to us. For, as you very justly remark, natural science and philosophy are so actively interested in the ques-
