Such movements are much more frequently caused by dreams. It is well known that children often laugh in pleasant dreams. A lady I know dreamed that she was blowing out a lamp; she made the corresponding movements with her mouth. She was awakened, and related the dream which had no doubt caused the movements of the mouth. Every one knows that children in especial often scream when they are dreaming of something exciting.

These movements are much more evident in the case of the persons we call somnambulists, sleep-walkers, night-walkers, with whom they are characteristic. The resemblance between hypnosis and somnambulism is so great that the name somnambulism1 is used for both (Richet). Hypnotism is called artificial somnambulia, or, better, spontaneous somnambulia, since artificial somnambulia is really as natural as the other, as Poincelot insists. As a rule, somnambulia is divided into three stages according to the extent of the movements exhibited: - (i) that in which the sleeper speaks; (2) that in which he makes all sorts of movements, but does not leave his bed; (3) that in which he gets up, walks about, and performs the most complicated actions. In my experience the first two stages are found in persons of sanguine temperament who are certainly not in a pathological condition. It is not yet finally decided whether the third state appears under pathological conditions only, as many still assume. From my own experience I am inclined to think that it is occasionally observed when there is no constitutional weakness, especially in children. If we want to show these states, we can invariably do it with the healthiest subjects.

As regards the movements in sleep, my own experience is that the persons who are most restless in natural sleep, who talk, or throw themselves about, are the most inclined to lively movements in hypnosis. In any case, the movements are also displayed in sleep. Consequently, the movements of subjects in hypnosis do not offer a fundamental contrast to sleep, especially when they are caused by suggested delusions of sense.

1 Bentivegni and Wundt have very properly termed the condition somnambulia instead of somnambulism, and other authors, Hirschlaff, for example, have recently accepted the change. The termination "ismus" when applied to other foreign words signifies an occupation, science, or the like, and not a state or condition. In the following pages I shall adhere to the terminology employed by the authors I have mentioned.

Spontaneous somnambulia is obviously very near akin to deep hypnosis, even if we maintain that the non-occurrence in hypnosis of those wild and illogical flights of fancy which occur in dreams constitutes a difference between the dreams of sleep and hypnotic suggestions, and it is exactly in spontaneous somnambulia that we find something analogous to hypnosis. It is evident, if we draw conclusions as to the contents of a somnambulist's dreams from his movements, that wild flights of thought may be absent in dreams; for surely we know that a subject of spontaneous somnambulia often com-, mences an action which is quite logical, and carries it out in his sleep.

The fact that a subject in hypnosis can carry on a conversation is not enough to mark off hypnosis from sleep, as Wernich erroneously supposes, for many persons answer questions and obey in sleep (Lotze, Berillon). According to my experience and that of others, certain persons easily answer in sleep when some one they know well speaks to them. A child will speak to its mother, and bedfellows to one another. A conversation is easily carried on when the waking person follows the sleeper's chain of thought and insinuates himself, so to speak, into his consciousness (Brandis). A lady I know, A., dreamed aloud of a person B. When Mrs. A.'s husband talked to her as if he were B., he was answered, but when he spoke in his own person he was ignored.

Finally, there are many persons who can hardly be induced to move in hypnosis, though they can be made to dream anything. Here the resemblance of sleep to hypnosis is particularly striking.

I hope that what has been said makes it clear that deep hypnosis need by no means be sharply distinguished from sleep.

As regards post-hypnotic suggestion, which is a very important phenomenon of hypnosis, we find that sleep presents not only many points of resemblance but even apparently identical phenomena (Liebeault, Exner, Sante de Sanctis). Of course the effect of night-dreams upon the organism is not so easy to observe as the effect of suggestion, as most dreams are forgotten. Still there are exceptions. People who dream of a shot, and wake in consequence, continue to hear the reverberation clearly after they wake (Max Simon). Others after waking feel a pain of which they have been dreaming (Charpignon). Aristotle maintained long ago that many of our actions have their origin in dreams. To this class belongs a case reported by Sauvet and Moreau de Tours in 1844, in which a man in ordinary sleep had visions which gradually influenced him in waking, and induced him to abandon his home. Tonnini mentions a rather inconclusive case of a woman who was induced by a dream to do something. Of course, such phenomena are very difficult to observe, but it is very probable that dreams have an after-effect on even thoroughly healthy people.

I will merely mention certain * phenomena which resemble these - the dreams that are continued into waking life, which may be compared to con-tinuative post-hypnotic suggestions. There are well-known vivid dream-images which are not recognized as dreams, and which are taken for reality even after waking (Brierre de Boismont). It is certain that even the most enlightened persons are influenced by dreams. Many are out of humour after having been annoyed by unpleasant dreams. The experiments lately made by Heerwagen have proved that persons who have dreamed much are in an unpleasant frame of mind the next day. I know of patients who are much worse after dreaming of their complaints; a stammerer will stammer more after dreaming about it. It is probable that erotic dreams belong to this class, because even when they terminate with the emission of semen, they stimulate, rather than inhibit, sexual desire. We find analogies with post-hypnotic suggestion everywhere. There are well-known cases in which persons have dreamed of taking an aperient with effect. Perhaps a case mentioned by Ferre may also be referred to here. A girl dreamed for several nights that men were running after her.