necessary to avoid hitting them. The hypnotic is in a similar situation. Sensorial impressions of which he is not conscious provoke apparently voluntary and reasoned acts.
The hypnotic, although his eyes are shut, perceives what is passing around him. The eyelids are not wholly closed. Movements perceived unconsciously, by the aid of the sight or hearing, are imitated by him involuntarily and under a constraint from which he can not withdraw himself, and with an almost servile exactness. Thus he will regulate his step according to that of the experimenter who makes him act, will raise his arm to the same height, will bend his body back and forth in accord with his model.
Some acts of imitation, such as yawning, laughing, crying, etc., take place even in the normal condition; generally the idea of a movement determines the action, but in induced sleep the contrary takes place, and the unconscious perception of a movement leads to its accomplishment. This relation explains the facility with which hypnotics are made to execute movements of which what we may call the sensation has been communicated to them in advance. If the subject is not disposed to follow the experimenter when he walks briskly in front of him to excite him, the operator has only to draw him lightly by the hand to make him follow with docility. We have thus explained the secret of the power which the magnetizer exercises over his subject. The former gives an order which the hypnotic does not apprehend, but which he executes nevertheless if he has unconsciously experienced a sensorial impression corresponding with the action which is commanded of him. In testing whether the hypnotic, after waking, remembers what has passed, it is important that he be not assisted by being asked a question the form of which will suggest the answer. If he is asked if he remembers any particular thing, his answer will always be "Yes"; but if he is asked, generally, what has taken place, he will answer that he does not know. The slightest allusion may cause the remembrance to revive; and unconscious traces may be recalled on the intervention of suggestive external excitations. The hypnotic condition, when divested of charlatanism, discloses a multitude of interesting physiological and psychological facts.
In a slight degree of hypnotism, the sensorium commune is still so free that the constraint of involuntary imitation does not exist. As long as consciousness is not obscured, the excitation of the motive apparatus by special sensations does not take place; but when consciousness disappears, the sensorial excitation becomes predominant. So profound states of unconsciousness may be produced that all traces of sensorial perceptions, and the possibility of executing automatic acts of imitation, will disappear. A more advanced symptom of hypnotism is painlessness. Sensibility returns with the cessation of the sleep. The exaggeration of the reflex excitation of the striated muscles is also striking and of surprising duration. A person who has been hypno-
