Page:Popular Science Monthly Volume 25.djvu/825

Rh very hot. The idea I had given him was remembered, the evidence of his sense of touch was disregarded.

There are certain attitudes which we usually assume under the influence of certain moods or ideas; from each of the muscles concerned in bringing about any one attitude, impulses travel up to the brain, and give rise to a definite muscular sensation which comes, therefore, to be associated with a particular mental mood. In mesmerized people the production of a definite muscular sensation not infrequently produces in the mind the mood with which it is, in the wakeful state, associated. At the same time ideas may be produced corresponding to the mood, and the ideas may give rise to particular actions, such as laughing, crying, fighting.

If the head is pushed back and the shoulders opened out, the face assumes a look full of pride or haughtiness, and, if the subject be asked what he is thinking about, he will give some answer indicating what a fine fellow he fancies himself to be. If, then, the head is bowed and the shoulders contracted, the aspect of the face changes to one of humility and pity. Occasionally it happens that a slight pressure on a single muscle, which causes it to contract, will by an irradiation of nerve-impulses produce the muscular sensations proper to a group of muscles, and this will give rise to the associated frame of mind. Thus very different feelings may be made to rapidly succeed one another in the mind of the subject by simply pressing on various muscles of the head and neck. At first sight such an experiment looks like a revival of the now happily forgotten phrenology.

I have said that, in a frog which remains mesmerized for any time, there is a considerable reflex depression—i.e., inhibition of the whole of the central nervous system; that there is an irradiation of inhibitory impulses. In man a similar irradiation of inhibitory impulses appears to take place: usually a mesmerized person if left alone passes gradually, but often rapidly, into a state of torpor; consciousness disappears, memory is lost, reflex action becomes difficult to obtain; finally, it may be, there is complete anæsthesia, a limb may be cut off without producing any movement or any pain. Since this torpor comes on without anything further being done to the subject, we may conclude that here, as in the frog, but to a much more marked degree, there is an irradiation of inhibitory impulses. The primarily inhibited centers send out inhibitory impulses to all other nerve-centers. Up to a certain stage, possibly throughout, any one or more centers may be brought back to a condition of activity by certain exciting stimuli, but when these cease the inexcitable condition is soon brought back by the inhibitory impulses streaming to them from other nerve-centers.

The extent to which the torpid condition develops itself varies in different individuals. It depends upon the condition of the nervous system, upon the relative intensities of the inhibitory and exciting impulses. As far as our present knowledge goes, it would appear that a