Organs which easily expand laterally by encroachment upon their neighbors, which is a common effect of local excitement, must be slow to make any impression upon the superjacent bone of the cranium. Cranioscopy, moreover, is incompetent to indicate the development of small regions or portions of a convolution; it gives but a rude survey of development. Being thus incapable of minuteness, accuracy and certainty, it cannot be considered a proper and sufficient basis for cerebral science. In the hands of Gall and Spurzheim, it had already very nearly attained its limits as regards the subdivision of organs, and the progress of their followers in discovery has been unimportant or fallacious.
To what, then, can we resort, when the failures of Pathology and Vivisection are admitted, and we perceive the limited extent of the uncertain results of Craniology? Shall we not be compelled to resort to the same methods of investigation in the brain, which have been so successful in establishing the physiology of the nerves, viz.: direct experiment in exciting and arresting the action of the various masses of nervous fibre. Every sound physiologist must perceive that we are compelled to resort to experiment, or else to rest contented in ignorance of the true cerebral physiology. Muller, perceiving this, remarks, “The principle for the advancement of the physiology of the nerves then remains the same, viz.: experiment on the living nerves.”
We therefore experiment on the living brain in that class of persons who are susceptible of being thus influenced; hence arises the last and most perfect method of cultivating Anthropology, by means of HUMAN IMPRESSIBILITY.
Our system of Anthropology relies, for its demonstration, upon human impressibility. Impressibility in its general sense, or the power of being affected by external agents, is proportional to the development of life. Inorganic matter is affected only mechanically or chemically—vegetation is powerfully affected by causes which would have no perceptible influence on stones or metals, and animals are affected by remote objects, by sounds, by the voice, and by other influences which do not affect vegetables. Animals of a higher grade are affected by many moral influences which produce no effect on the inferior classes, and man, having the fullest development of all, is continually receiving a variety of influences from nature and society, to which animals are wholly insensible. As man is superior to animals in impressibility, so is the man of genius or the man of superior moral sentiments more easily affected by everything that addresses the intellect or the sentiments, than the ignorant and selfish classes of society. Superior impressibility is then the result of a superior development of the organs which feel the various impressions. In the highest order of genius capacities exist which recognize a thousand subtle influences and beauties in Nature of which common minds are unconscious, and the psychic influence of a human being is instantly and thoroughly recognized.
For the purpose of analytical experiments upon the human functions, we require the development of a faculty which shall feel the influences we use. We look to the various forms of Sensibility. The organ of physical sensibility is situated in the temples, immediately over the cheek bone. It feels the influences of the various objects which affect the sense of feeling in all its modifications. Heat and cold, moisture and dryness, sound, light, and all the imponderable fluids produce their effects upon this region, and the more it is developed, the more powerfully are we affected by such agencies.
The portion of Sensibility which feels the influences of the human nervaura, is the highest portion of the organ, where it connects with Modesty, Somnolence, and Ideality. This we regard as the special organ of Nervauric Impressibility, because it renders the system so sensitive to the nervaura, as to be strongly affected whenever it is applied.
Mental impressibility is dependent upon intellectual organs, which feel the influences of mind. The power of recognizing mental action is dependent upon the internal part of the front lobe, located just above the root of the nose. This organ gives physiognomical talent, and a ready tact in appreciating the expression of mind through the eye, countenance, and gestures. It is a channel of mental sympathy, as displayed in the intercourse of society, and in the experiments of animal magnetism. By means of this organ, a general relation is established between the mind of the operator and that of the subject, which may exist without the capacity for local impressions, which would develop particular organs. It is devoted, however, to active perception rather than to passive impression. The faculty of being mentally impressed depends also upon the region of Spirituality and Marvellousness.
Mental and nervous impressibility being dependent upon these organs, it follows that a large development of the front lobe favors Impressibility, and that the occipital organs tend to diminish it. Impressibility lies in a group of organs which sustain it, and may be expected to accompany its development. Sensibility, Somnolence, Dreaming, Ideality, Modesty, Humility, Organic Sensibility, Relaxation, etc., are its natural accompaniments; hence it will be found most abundantly in those classes of society which are most remarkable for refinement, sensitiveness, modesty, diffidence, humility, or submissiveness, disease, languor, debility, and intellectual excitement. Religious excitement, love, mirthfulness, thoughtfulness, imagination, benevolence, sympathy, sincerity, faith, philanthropy, hope, epicurism, intemperance, ardor, spirituality, effeminacy, imitation, romance and, in short, all amiable, sensitive, intellectual, refining, relaxing influences may be regarded as promotive of impressibility, and their opposites as calculated to destroy it.
It is fortunate that disease promotes impressibility, for it enables the sick to be relieved by manipulation, and it causes medicines to operate more efficiently upon morbid constitutions or organs, which has been fully demonstrated by the Homœopathic School of therapeutics. But impressibility does not imply disease, although it may make the system more accessible to slight morbific agencies. We find individuals occasionally, of the highest tone of health and bodily vigor, who are highly impressible. Nor does it imply mental weakness, for it is highly congenial to intellectuality, and is occasionally found among the strongest and most cultivated minds. Nervous Impressibility is that condition in which the nervaura has a powerful influence—in which the action of the brain and all the vital functions of the constitution may be controlled and indefinitely changed by the application of the hands of another individual—in which we are susceptible of being totally revolutionized in character by application of the fingers to the various organs, so as to become, for the time being, miserable or gay, philosophical, felonious, murderous, angry, stupid, insane, idiotic, drowsy, hot, cold, credulous, sceptical, timid, courageous, vain, indolent, sensual, hungry, diffident, haughty, avaricious, etc.; and in which the muscular strength, secretions, circulation, pulse, respiration, senses, and morbid or healthy conditions of the frame may be changed or controlled by the nervaura emitted from the hand of the operator acting upon the brain of the subject.
The number of individuals who can be thus affected is different in different places. In southern climates they are more numerous than in northern—in the pleasant weather of summer more than in winter—in lecture rooms, ball rooms and places of fervid religious worship, more than in the street and market place, where the intellectual and moral faculties are less predominant. In the Southern States of the Union, thirty or forty per cent. of the population will give at once distinct evidence of impressibility. In the more northern, about ten per cent. will give indications of an influence from the hand. A moderate degree of impressibility which is almost universal in the South, belongs to more than half in the North.