Later, when awakened, he is in precisely the same position as are victims of spontaneous dissociation--such as the Philadelphia plumber, and Doctor Prince's puzzling neurasthene, BCA. That is to say, he is unable to give any account of what he has said and done during hypnosis. Thus the effect of hypnotism is to produce a psychical cleavage so profound as to involve the action, within a single organism, of two separate selves. This has been demonstrated by a long line of scientific investigators, including physicians and psychologists of international reputation. Moreover, these investigators have shown that, even after a person has been brought out of the hypnotic state, the self evoked by hypnotism may in some inscrutable way continue operant without his suspecting for a moment its existence and influence. Impressive proof of this is found in the execution of what are known as post-hypnotic commands. A hypnotized person is told that, after being de-hypnotized, he is to perform a certain act on receiving a certain signal, or at the expiration of a certain time. As usual, when restored to his conscious, waking state, he remembers nothing of the command imposed on him; but when the signal is given, or the appointed time arrives, he feels an irresistible, and to him inexplicable, impulse to carry out the suggested idea. Thus, in one series of fifty-five experiments made by the foremost English authority on hypnotism, Doctor J. Milne Bramwell, the subject, a young woman of nineteen, was ordered to perform a specified act at the end of a varying number of minutes, ranging from three hundred to more than twenty thousand. Not once, on being de-hypnotized, did she remember what she had been told to do, although offered a liberal reward if she could recall the commands given her. Nevertheless, only two of the fifty-five experiments were complete failures, while in forty-five she executed the commands at exactly the moment designated, and in the remainder was at no time more than five minutes out of the way. As to the complete failures, Doctor Bramwell ascertained that in one instance she had mistaken the suggestion given, and in the other the circumstances were such that the command might have been executed without his being aware of it.[48] [48] These experiments by Doctor Bramwell were first reported by him in the _Proceedings of the Society for Psychical Research_, vol. xii, pp. 176-203. Equally astonishing results are reported by the brilliant group of Frenchmen who, uniting under the direction of Doctor A. A. Liébeault, were the first to make an organized investigation of the cause and effects, the possibilities and limitations, of hypnotism. One of these French investigators, Doctor Hippolyte Bernheim, once hypnotized an old soldier, and asked him: "On what day in the first week of October will you be at liberty?" "On the Wednesday."