Among other consequences of this exalted susceptibility of the waking portions of the brain may be noticed the effect of suggestions by others upon the mind of the somnambulist. Numerous examples scattered through the literature of the subject21 illustrate the manner in which the course of our ordinary dreams may be thus directed. The hypnotic dream is far more easily modified.22 The simplest manifestations of such influence are exhibited in movements in obedience to the command of the hypnotizer. Next in rank are those more complicated actions that are effected by excitement of the imitative faculties of the subject. Every suggested movement that can be in any way perceived by the patient will be at once reproduced. Various emotions and passions may thus be aroused by simply placing the sleeper in the appropriately suggestive attitudes. Under the influence of a pregnant idea intruded upon the mind of the patient the subsequent association of ideas will suffice for the evolution of a complicated series of hallucinations, as in the case of a young woman, who on being directed to put out her tongue immediately began to feel sensations of uneasiness in her stomach, followed by nausea and attempts at vomiting, accompanied by the impression of being on shipboard. In the lowest grades of the hypnotic state consciousness may remain, and the subsequent recollection of the events of the paroxysm may be quite persistent. In such cases illusions that were produced by suggestions from other minds generally survive in memory and become the causes of serious delusion. Witness the manner in which susceptible individuals, partially hypnotized in a so-called spiritual circle, believe in the reality of the illusions which have occupied their senses during a séance.
21 Carpenter's Physiology, 8th ed., p. 765; Le Sommeil et les Rêves, par L.-F. Alfred Maury, 4th ed., p. 153 et seq.
22 Loc. cit., p. 357.
A higher degree of insensibility to ordinary impressions is necessary to the production of the phenomena of passive obedience and of automatic imitation. It is probable that the degree of sensory hyperæsthesia which enables certain hypnotic patients to read the thoughts of others belongs rather to the first than to the last of these classes. This capacity is usually associated with preservation of consciousness and memory, and is, essentially, a mere exaggeration of that power which all possess in greater or less degree. Numerous well-authenticated examples of a surprising manifestation of this faculty have been recorded, so that the possibility of its existence no longer admits of doubt.23 In all cases it has been remarked that the hypnotic mediums can only respond correctly to questions for which the true answer is present in the mind of the questioner. For all other interrogations the replies are delivered purely under the influence of random suggestion. In certain of these cases the pathway of communication lies through actual physical contact, as in ordinary mind-reading, where the insensible molecular oscillations of the muscular elements of one individual serve to guide the movements of another. But more frequently the transmission of ideas is effected through the eyes. With these organs the table-rapper or the planchette-writer reads the unspoken words of the questioner in a manner very like, yet vastly more deliberate than, that by which deaf-mutes now learn to interpret the movements of the lips of persons with whom they converse. This fact is well illustrated by the experience of Maury24 in an interview with a celebrated table-rapper, who without the slightest hesitation made known to him the age, name, and date of death of a brother whom he had lost. She also gave the same information regarding his father, and related the names of other persons upon whom he had fixed his attention. But if he turned away his face or concealed his eyes, so that the woman could no longer watch their expression, her responses ceased to be of any value.
23 Luther V. Bell, Two Dissertations on what are termed the Spiritual Phenomena, read at the meetings of the Association of Medical Superintendents of American Insane Hospitals at Washington and Boston in 1854 and 1855.
24 Le Sommeil et les Rêves, 4th ed., p. 361.
In these partial developments of the hypnotic state it is worthy of note that the phenomena of sleep are so few and so comparatively insignificant that they are usually overlooked. Hence the veil of mystery which has so often obscured the interpretation of such cases. Careful observation, however, will always detect some characteristic departure from the normal standard—some loss of balance between the different parts of the nervous system—by means of which the true relations of each example may be determined.
TREATMENT.—A large proportion of the phenomena of somnambulism and hypnotism depend rather upon an originally irritable organization than upon a specially diseased condition of the nervous system. Their treatment, therefore, frequently resolves itself into the management of hysteria or of cerebrasthenia. But if the manifestations of somnambulism develop for the first time in a person advanced in years, who has previously enjoyed good health and a sound mind, it should be regarded as an omen of grave import, signifying the imminence of organic cerebral disease. Though the meaning of such incidents is less sinister in early life, they reveal an ill-balanced state of the nervous system and an imperfect process of nutrition in the growing body. Such children are the frequent victims of night-terrors, the form of disorder most commonly evolved by their somnambulistic proclivities. The treatment of night-terrors should therefore be chiefly directed to the invigoration of the general health of the patient. Indigestion and malnutrition are among the most prominent antecedents, and they should constitute the principal objects of therapeutical attention. Constipation is usually present. This may be relieved by the use of compound rhubarb powder or any other gently stimulating laxative. Digestion should be aided with pepsin as soon as the catarrhal condition of the alimentary canal, so uniformly present, has been measurably improved. Cod-liver oil or its substitutes should be administered for a long period of time. If the nocturnal paroxysms be frequently renewed, it may be well to employ the bromides, either with or without chloral hydrate; but as a general rule it is better to rely upon hygienic and restorative treatment, rather than upon any form of merely hypnotic medication.