Béclard almost completely demonstrated the truth of Roget's hypothesis concerning the action of "the nervous fluid" by cutting a nerve of considerable size, adjoining a muscle, which induced paralysis in this part. Perceiving the contractile action reappear, when he approached the two ends of the nerve to the distance of three lines, he became convinced that an imponderable substance, a fluid of some kind, traversed the interval of separation, in order to restore the muscular action. By another experiment he demonstrated its striking analogy to galvanic electricity. The late Professor Keil, of Jena, also made some very interesting experiments of the same character, one of which tends to demonstrate the susceptibility of the nervous system to the magnetic influence, and the efficacy of the magnet in the cure of certain infirmities. It was communicated by him to a meeting of the Royal Society of London more than fifty years since. If we are justified, then, in assuming the existence of this nervous fluid, writes Colquhoun, in 1836, whether secreted by, or merely conducted by the nerves, and of its analogy to the other known, active, and imponderable fluids, and of its capability of external expansion, as in the case of electricity, it does not appear to be a very violent or unwarrantable proceeding to extend the hypothesis a little further, and to infer that it is also capable of being transmitted or directed outwards, either involuntarily or by the volition of one individual, with such energy as to produce certain real and perceptible effects upon the organism of another, in a manner analogous to what is known to occur in the case of the torpedo the gymnotus-electricus, etc. Should it be that Mr. Keely's compound secret includes any explanation of this operation of will-force, showing that it may be cultivated, in common with the other powers which God has given us, we shall then recover some of the knowledge lost out of the world, or retained only in gipsy tribes and among Indian adepts.