torpor of the other organs, in consequence of an increased demand of sensorial power from the common stock, to supply the action of the sense and muscles immediately engaged, every other sense will probably be thrown into a deeper sleep or torpor than if the whole had been quiescent. Hence, the ears may not be roused even by a sound that might otherwise awake the sleeper. He may be insensible not only to a slight touch, but a severe shaking of the limbs; and may even cough violently, without being recalled from his dream. Having accomplished the object of his visionary pursuit, he may safely return, even over the most dangerous precipices—for he sees them distinctly—to his bed; and the organ of sight being now quite exhausted, or there being no longer any occasion for its use, it may once more associate in the general inactivity, and the dream take a new turn, and consist of a new combination of images."
Dr. Pritchard, in his "Treatise on Insanity," says "there is an obvious relation between the state of the faculties in somnambulism and that which exists during dreams. It is indeed probable that somnambulism is dreaming in a manner so modified that the will recovers its usual power over muscular motion, and likewise becomes endued with a peculiar control over the organs of sense and perception. This power, which gives rise to the most curious phenomena of somnambulism, is of such a kind, that, while the senses are in general obscured, as in sleep, and all other objects are unperceived, the somnambulator manifests a faculty of seeing, feeling, or otherwise discovering those particular objects of which he is in pursuit, towards which his attention is by inward movement directed, or with which the internal operations of his mind bring him into relation. As in dreams, so likewise in somnambulism, the individual is intent on the pursuit of objects towards which his mind had been previously directed in a powerful manner, and his attention strongly roused; he is in both states impelled by habit, tinder the influence of which he repeats the routine of his daily observances. A somnambulator is a dreamer who is able to act his dreams."
"Somnambulism," observes Macnish, in his "Philosophy of Sleep," "I have had occasion to remark, is very common among children; and I believe that it more frequently affects childhood than any other age. It is a curious, and not easily explained fact, that the aged, though they dream more than the middle-aged, are less addicted to somnambulism and sleep-talking. Indeed, these phenomena are seldom noticed in old people.
"It has been matter of surprise to many, that somnambulists often
