Page:Popular Science Monthly Volume 33.djvu/784

764 movements, and to experience hallucinations and illusions of the senses. A solution of quinine is drunk with every show of satisfaction if the operator merely states with sufficient emphasis that it is a delicious cup of chocolate.

The fifth degree of hypnotism is known as light somnambulism. In deep somnambulism (sixth degree) the subject has no memory whatever of what has passed during the sleep. There is absolute amnesia. Nevertheless he can hear and obey suggestions with great readiness. There are cases of deep somnambulism, however, in which there is scarcely any suggestibility, and in which all the senses appear to be in temporary abeyance.

The above description of the various grades of hypnotism is far from satisfactory, for every person preserves in some degree his own individual peculiarities and impresses them upon the hypnotic state, and this gives rise to an almost infinite number of varieties which overlap one another in every imaginable way.

The proportion of somnambulists to the total number of persons who can be hypnotized is large, being about nineteen per cent in adults. Sex seems to be an unimportant factor, contrary to what was formerly supposed, for the preponderance in favor of women is only about one per cent. The proportion of somnambulists among children is much higher, being about twenty-six per cent in children from one to seven years of age. More than half the children between the eighth and fourteenth year are somnambulists.

I have heretofore only spoken of the phenomena which are present during the actual sleeping state of the hypnotized subject. In addition to these, there is a class of manifestations which make their appearance after the subject has awakened. These post-hypnotic phenomena, as they are called, are the result of suggestion, and can only be produced in somnambulists. The manifestations themselves only differ from those of somnambulism in that they persist, or only take effect, after the subject awakes. Thus, we can suggest post-hypnotic acts, illusions of the various senses, and hallucinations. For example, a good somnambulist is hypnotized and told that on awaking he will commit a certain act, that he must commit it, and can not offer any resistance to his desire to commit it. Accordingly, when he awakes he executes the suggestion which has been insinuated into his mind, either literally or with some slight modification, and, not having any recollection of what has been told him, believes that his act is spontaneous. These cases afford the best illustration I know of the relativity of our freedom of will, and of the truth of Spinoza's saying, that our consciousness of free-will is but ignorance of the causes of our acts. If the act which has been suggested is one