A very curious light however is thrown on them by phenomena which occur in abnormal states of the brain, as in trance, somnambulism, and hypnotism. In the latter, by straining the attention on a given object or idea, such as a coin held in the hand or a black wafer on a white wall, the normal action of the brain is, in the case of many persons—perhaps one out of every three or four—thrown out of gear, and a state induced in which the will seems to be annihilated, and the thoughts and actions brought into subjection to the will of another person. In this state also a cataleptic condition of the muscles is often induced, in which they acquire enormous strength and rigidity. In somnambulism outward consciousness is in a great measure suspended, and the somnambulist lives for the time in a walking dream which he acts and mistakes for reality. In this state old perceptions, scarcely felt at the time, seem to revive, as in dreams, with such wonderful vividness and accuracy that the somnambulist in acting the dream does things altogether impossible in the waking state. Thus an ignorant Scotch servant-maid is said to have recited half a chapter of the Hebrew version of the Old Testament: the explanation being that she had been in the service of a Scotch minister, who was studying Hebrew, and who used to walk about his room reciting this identical passage. It would seem as if the brain were like a very delicate photograph plate, which takes accurate impressions of all perceptions, whether we notice them or not, and stores them up ready to be reproduced whenever stronger impressions are dormant and memory by some strange caprice breathes on the plate. Most wonderful, however, are some of the phenomena of trance. In this case it really seems as if two distinct individuals might inhabit the same body. Jones falls into a trance and dreams that he is Smith. While the trance lasts he acts and talks as Smith, he really is Smith, and even addresses his former self Jones as a stranger. When he wakes from the trance he has no recollection of it, and takes up the thread of his own life, just as if he had dozed for a minute instead of being in a trance for hours. But if he falls into a second trance, days or weeks afterwards, he takes up his trance life exactly where he dropped it, absolutely forgetting his intermediate real life. And so he may go on alternating between two lives, with two separate personalities and consciousnesses, being to all intents and purposes now Jones and now Smith. If he died during a trance, which would he be, Jones or Smith? The question is more easily asked than answered; but it certainly appears as if with one mode of motion in the same brain you might have one mind and personal identity associated with it, and with another mode of motion different ones.