I know that this matter of the divining of numbers thought of is in bad odor. It lacks a certain pedantic and scientific form. Yet I have not hesitated to insist on it; for there are few experiments in which is better manifested the _mixed character_ of the phenomenon,--physical power developed and applied outside of ourselves by the effect of our will. Just because it forms the great offense, or stumbling block, I am unwilling to be shame-faced about it. I maintain, besides that this is just as scientific as anything else. True science is not tied to the employment of such and such a process or such and such an instrument. That which a fluidometer would show would be no less scientifically demonstrated than what is seen with the eyes and estimated by the reason. Let us go on, however. We have not yet reached the end of our proofs. One of these has always especially struck me: I mean the proof derived from failures. It is claimed that the movements are produced by the action of our muscles, by involuntary pressure. Now here are the same operators who yesterday secured from the table the fulfilment of their most capricious desires; their muscles are as strong, their vivacity is as great, their desire to succeed is perhaps keener--and yet nothing! absolutely nothing! A whole hour will pass without the least rotation beginning; or, if there are rotations, levitations are impossible to procure; what little is done by the table is done feebly, dismally, and as if reluctantly. I repeat it again, the muscles have not changed; then why this sudden incapacity? The cause remaining identically the same, whence comes it that the effect varies to such a degree? "Ah!" says an objector, "you are talking of involuntary pressure, and say nothing about voluntary pressure, of fraud, in short. Don't you see that the cheaters may be present at one sitting and not appear at another, that they may act one day and not give themselves the trouble on the next?" I will reply very simply, and by facts. "The cheaters are absent when we do not succeed!" But it has happened many a time that our personnel has not been changed in any way. The same persons, absolutely the same, have passed from a state of remarkable power to a state of comparative impotence. And that is not all. If there exists no operator whose presence has preserved us from failures, no more does any exist whose absence has rendered us incapable of success. With and without each one of the members of the chain we have succeeded in performing all the experiments,--all without exception.