of a single word in a sentence. Thus, for instance, if a line of poetry is read to a patient during his sleep, the whole line may sometimes be recalled to his memory, when awake, by repeating a single word of the line. Again, we know from daily experience that the most complicated neuro-muscular actions—such as those required for piano-playing—become by frequent repetition "mechanical," or performed without consciousness of the processes by which the result is achieved. So it is in the case of hypnotism. Actions which have been previously rendered mechanical by long habit are, in the state of hypnotism, performed automatically in response to their appropriate stimuli. There being a strong tendency to imitate movements, these appropriate stimuli may consist in the operator himself performing the movements. Thus when Heidenhain held his fist before his hypnotized subject's face, his subject immediately imitated the movement; when he opened his hand his subject did the same, provided that his hand was visible to his subject at the time. Also, when he clattered his teeth, the hypnotized patient repeated the movement, even though the patient could only hear, and not see, the movement; similarly, the patient would follow him about the room, providing that in walking he made sufficient noise to constitute a stimulus to automatic walking on the part of his patient. In order to constitute stimuli to such automatic movements, the sounds or gestures must stand in some such customary relation to the movements that the occurrence of the former naturally suggests the latter.
Another characteristic of the hypnotic state is that of an extraordinary exaltation of sensibility, so that stimuli of various kinds, although much too feeble to evoke any response in the ordinary condition of the nervous system, are effective as stimuli in the hypnotic condition. It is remarkable that this state of exalted sensibility should be accompanied by what appears to be a lowered, or even a dormant, state of consciousness. It is also remarkable that this exaltation of sensibility does not appear to take place with what may be called a proportional reference to all kinds of stimuli. Indeed, far from there being any such proportional reference, the greatly exalted state of sensibility toward slight stimuli is accompanied by a greatly diminished state of excitability toward strong stimuli. Thus, deeply hypnotized persons will allow themselves to be cut, or burned, or to have pins stuck into their flesh, without showing the smallest signs of discomfort. Heidenhain is careful to point out the interesting similarity, if not identity, between this condition and that which sometimes occurs in certain pathological derangements of the central nervous system, as well as in a certain stage of anæsthesia, wherein the patient is able to feel the contact of the surgical instruments, while quite insensible to any pain produced by the cutting of his flesh. Reflex sensibility, or sensibility conducing to reflex movements, also undergoes a change, and it does so in the direction of increase, as might be expected from
