In recent years a quasi-unconscious state, induced by suggestion and called the hypnotic trance, has come to occupy a very important place in the popular mind. Hypnotism, as the general consideration of this state is known, has attracted not a little attention, as well from physicians as from those interested in psychology. The hypnotic (Greek, [Greek text], sleep) trance is a condition in which voluntary brain activity is almost completely in abeyance, though the mind is able passively to receive many impressions from the external world. There are very curious limitations in the effect of the hypnotic state upon the various senses. While visual sensations, and, as a rule also, impressions from the tactile sense, lose their significance, or are translated according to the will of the person active in producing the hypnotic state, or of some person present making suggestions, auditory sensations are quite normally perceived. The patient has all the appearance of being asleep, though motions, and even locomotion, are often possible, and are performed as if the patient were walking in sleep. The hypnotic state is a partial sleep, then, of the motor side of the nervous system and of portions of the sensory nervous system. Certain of the higher intellectual powers, however, are entirely awake, and capable of being impressed through the hearing, and thus hypnotic suggestion has a place. For a time, under the influence of Charcot and his disciples, there was a very generally accepted opinion that the hypnotic trance was a pathological condition, somewhat allied to the cataleptic phase of major hysteria. It is well known that persons suffering from severe attacks of hysteria {130} may, while apparently unconscious, yet receive suggestions through the hearing. On the other hand, the production of cataleptic and other strained attitudes, in the maintenance of which fatigue seems to play no part, is possible by means of hypnotic suggestion in susceptible individuals. Further investigation, however, seems to have shown that the hypnotic state is rather to be considered as a quasi-physiological condition, somewhat related to sleep, all the mystery of which is not as yet understood. This is not surprising when we realise that such a normal and absolutely physiological condition as healthy sleep is yet without a satisfactory explanation on the part of physiologists. Hypnotism is recognised now as having a certain limited power for good, though the benefit derived from it is apt to be temporary, and the operator loses his power after a time,--not so much failing to produce the hypnotic condition, as failing to have his suggestions favourably accepted by the subject While the Nancy school of hypnotism insisted that most people were susceptible to the hypnotic trance, it is now generally considered that something less than 40 per centum of ordinary individuals can be brought under its influence.