A rather curious observation ought to be made here. Several times during the course of this seance, and during the levitation of the table, I said, "There is no spirit." Every time I said this two violent blows of protestation were struck in the table. I have already remarked that, generally, we are supposed to admit the Spiritualistic hypothesis and to ask a spirit to exert himself in order that we may obtain the phenomena. We have here a psychological matter not without importance. Still, it does not seem to me, for all that, to prove the real existence of spirits, for it might happen that this idea was necessary to the concentration of the forces present and had a purely subjective value. Religious zealots who believe in the efficacy of prayer are the dupes of their own imagination; and yet no one can doubt that certain of these petitions appear to have been granted by a beneficent deity. The Italian or Spanish girl who goes to beg of the Virgin Mary that she will punish her lover for an infidelity may be sincere, and never suspects the strangeness of her request. In dreams we all converse every night with imaginary beings. But there is something more here: the medium really duplicates herself. I take the point of view solely of the physicist whose business is to observe, and I say, whatever may be the explanatory hypothesis you may adopt, there exists an invisible force derived from the organism of the medium, and having the power to emerge from him and to act outside of him. That is the fact: what is the best hypothesis to explain it? 1. Is it the medium who herself acts, in an unconscious manner, by means of an invisible force emanating from her? 2. Is it an intelligent cause apart from her, a soul that has already lived upon this earth, who draws from the medium a force which it needs in order to act? 3. Is it another kind of invisible beings? Nothing authorizes us to affirm that there may not exist, side by side with us, living, invisible forces. There you have three very different hypotheses, none of which seems to me, as far as my personal experience goes, to be as yet conclusively proved. But there certainly emanates from the medium an invisible force; and the participants, by forming the psychic chain and by uniting their sympathetic wills, increase this force. This force is not immaterial. It may be a substance, an agent emitting radiations of wave-lengths which make no impression on our retina, and which are nevertheless very powerful. In the absence of light rays it is able to condense itself, take shape, affect even a certain resemblance to the human body, to act as do our organs, to violently strike a table, or touch us. It acts as if it were an independent being. But this independence does not really exist; for this transitory being is intimately connected with the organism of the medium, and its apparent existence ceases when the conditions of its production themselves cease.