The hand also became cyanotic and hard, and the temperature fell about three degrees. At all events, no matter how sceptical we may be, we are not justified in straightway denying the possibility that suggestion may induce organic changes in the skin merely because we have never seen such changes, or because their occurrence is rare. Nevertheless, rarities dp occur, such as miscarriages which cannot be accounted for, triplets, and millionaires. We believe in their existence, although we may have never seen them ourselves. Because a phenomenon is rare, or that we have never observed it, is no argument against the possibility of its occurrence. Consequently the observation of any rare phenomenon is valuable.

(2.) Psychology.

In the foregoing sections we have studied the physical symptoms of hypnosis, and have only casually touched upon some psychical phenomena. We will now proceed to investigate the latter more closely, but I shall naturally only discuss such as are characteristic from our present point of view. For practical reasons I must first speak of the memory, because it determines the other psychical activities. Without memory no action of the understanding is possible, and all the higher mental functions depend upon the memory. Memory during and after hypnosis has been specially studied by Richet, Delbceuf, Dichas, Beaunis, and Pitres.

Memory, in its broadest sense, consists of three parts: firstly, of the power of retaining ideas; secondly, of the power of reproducing these ideas; thirdly, of the power of recognizing the ideas and of localizing them correctly in the past. To make this clear, let us take any event which we remember - for example, a severe scolding given to us by a teacher. The memory in this case acts in three ways: in the first place, what is said is received and retained in it; in the second place, the memory can reproduce the lecture; and in the third place, we can place it in its correct position in time by recalling its relation to other events, such as being at the school, etc. But the power of retention is only made evident by the ability to reproduce an impression; consequently the first two faculties are apparently interdependent. Still, it is customary to make a theoretical distinction, and William James calls retention primary memory, and reproduction secondary memory. At all events, although reproduction may be the only proof of the retention of ideas, the two processes can easily be distinguished. This is easily demonstrable. There are times when we cannot recall certain events, although at other even more remote periods we can do so.

Which means that although in the first case the impression could not be immediately reproduced, it had nevertheless been retained because it was reproduced later on; a fact which shows that the two processes must be differentiated. The same holds good of the third power - that of correctly localizing past events. That a name should occur to me without my being able to connect it with some past event shows that the third of the powers which we have discussed is distinct from the simple reproduction of an impression.

The retention of ideas in hypnosis has been little investigated. Beaunis has found no essential difference in this respect between hypnosis and waking life. Max Dessoir has also made experiments, the results of which he has communicated to me. From these it appears that memory is weakened in deep hypnosis, when this is not prevented by suggestion. Max Dessoir repeated a number of syllables which the hypnotic was to try to remember; a suggestion of improved memory was entirely avoided. Under these circumstances the hypnotized subject remembers fewer syllables than did the same person when awake. The older mesmerists (Wienholt), on the contrary, believed that the memory was intensified in the magnetic sleep; poems could be learned by heart in a much shorter time than in the normal state. However, these investigators did not altogether avoid suggestion.

Is the chain of memory in ordinary life broken by hypnosis or not? It was formerly supposed that the subject always forgot on awaking what had happened during hypnosis; but this view has not proved correct

In the lighter hypnotic stages, especially in the first group, there is rarely any abnormality of memory; the subject remembers everything in the hypnosis of which he was conscious in normal life, and after hypnosis recollects all that had occurred during that state. In the deeper hypnoses it is very different; they belong for the most part to the second group, and only a few to the first, and there is loss of memory (amnesia) after the hypnosis. The subject is much astonished when he hears what he has been doing during the hypnosis - that he has been running about, that he has had hallucinations. Sometimes, however, a dim memory persists, like the memory of a dream. I suggest to some one the hallucination of a bird flying about the room; the hypnotic tries to catch it, amuses himself for a long time with it, gives it sugar, puts it in an imaginary cage, and so forth. After waking he dimly recollects that he has seen a bird, but that is all; he certainly does not believe that he has left his seat.

However, there are certain people who recall everything after being told what they have done during the hypnosis.

In other cases, associations of ideas will call up memory. A hint is given to the hypnotic after the awakening and everything recurs to him (Heidenhain). There is something of this sort in dreams; we very often remember a whole dream when we see some object that is in any way connected with it (Delbceuf). The same thing happens when a person is able to repeat a quotation or a poem directly he has heard the first words. Let us consider an example in hypnosis. I suggest a concert to a hypnotic; he hears various pieces, and among them the overture to Martha; meanwhile he eats his supper at the concert, drinks his beer, and talks to imaginary people. After the awakening there is no trace of memory. I ask him then if he knows the opera of Martha; this suffices to recall nearly all the events of the hypnosis. Sometimes memory is aroused in the same way by pure chance. X. believes in hypnosis that he sees a number of persons he knows at my house whose presence I have suggested to him. He goes through several scenes with them, but remembers nothing on awaking. Only when he meets one of the persons several days later does the whole thing recur to him.