Chap. XI.—the Principal Methods of Studying the Brain.

Cranioscopy, Pathology, and Vivisection, their failures recognized—Limitations of Craniology and its stationary condition—Human Impressibility explained—Its prevalence in different climates—Method of testing it.

In what manner shall we proceed to study the brain? All must admit the necessity of a thorough study of its anatomy; yet, unless we learn something of its functions, this anatomy is profitless and uninteresting; hence cerebral anatomy was crude and erroneous until, revolutionized by Gall and Spurzheim, it assumed a philosophical character and became connected with a doctrine of the cerebral functions.

For the study of these functions three principal methods have been adopted by eminent scientists: 1st. The method of Cranioscopy, practiced by Gall and his followers. 2d. The study of Pathological Anatomy. 3d. The mutilation of the brains of living animals. But neither Cranioscopy, Pathology, nor Vivisection has given satisfactory demonstrations, nor does the whole scope of the alleged results of all embrace more than half of the cerebral functions.

The results of Vivisection have been unsatisfactory. But it has shown that slicing away the anterior and upper parts of the brain of an animal produces a state of partial stupor—a loss of its intelligence and mental characteristics, without producing any great detriment to its muscular and physiological functions; while injuries inflicted upon the basilar parts of the brain produce evident derangements of muscular action, and are more dangerous to life. Vivisection has been almost entirely fruitless for the discovery of psychic functions, but in the hands of Prof. Ferrier and the continental vivisectors it has thrown much light upon cerebral psychology, and as I shall hereafter show, has confirmed my own discoveries.

Pathological Anatomy, too, has been extremely unprofitable. “The results of Pathological Anatomy (says Muller) can, however, never have more than a limited application to the physiology of the brain. We are unacquainted with the laws according to which the different parts of the organ participate in the functions of each other, and we can only, in a general way, regard as certain that organic diseases in one part of the brain may induce changes in the function of other parts; but from these facts and the results of Pathological Anatomy, we cannot always draw certain conclusions.” Mr. Solly, after commenting on the general failure of Vivisection, remarks, “From pathology we might naturally expect surer evidence; but even here the physiologist who carefully examines its records is doomed to disappointment. As will be proved hereafter, no certain light has yet shone on physiology from this source.” Cerebral pathology will not continue to be so barren a study when we have a true cerebral physiology to guide us. I find all pathological cases instructive as confirmations and illustrations of true cerebral science.

The method of Dr. Gall—studying the growth and development of the different parts of the brain, as indicated by the cranium—is the most simple, rational and successful of all the methods adopted up to the present time. In his hands it has elicited a valuable and practical, though rude, system of phrenology. But Craniology or skull-study cannot perfect, nor can it positively demonstrate, the science.

The observations of the craniologist are continually liable to error. The irregular thickness of the skull constitutes a great difficulty in the way of exact observations. By great expertness and accuracy of observation, he may overcome this difficulty in a great degree, but whenever the brain is subject to any remarkable influence, increasing or diminishing the activity and size of particular organs, the external form fails to indicate the internal condition, because it can change but slightly, and with slowness, after the skull is fully developed and ossified. Were the skull composed of more pliable materials, cranioscopy would be more accurate in its facts, but while it preserves a uniform exterior, the interior often undergoes remarkable changes. Convolutions that are frequently called into action become better supplied with arterial blood, expand and grow, while the adjacent portion of the inner plate of the skull becomes absorbed, and presents a remarkable indentation. Convolutions that are seldom in action shrink in size, and the adjacent bone grows in upon them. Thus the skull becomes thinner at the site of every active organ, and thicker over every convolution that is inactive. The translucency or opacity of the different parts of the skull, when a light is placed in its interior, generally indicates the active and inactive organs. Hence, many skulls of fine exterior reveal, upon interior examination, a degenerate character. Criminal heads generally present remarkable opacity and thickness in the region of the moral organs, with distinct digital impressions from the convolutions of the lower organs.

Thus all craniological observations are liable to inaccuracy, even as regards development, and much more in regard to functional power. The activity, power and predominance of an organ may be essentially changed, without making any perceptible impression upon the interior of the skull, for an indefinite period. Changes in excitement and circulation, that revolutionize the character, may leave but a slight impression upon the interior, and none upon the exterior of the cranium. The external configuration of the skull is therefore not a true criterion of character when the influences of education, society, food, drink and disease have greatly changed the natural bias, although reliable in a strictly normal condition of brain and cranium.

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.

Impressible subjects may be selected by the development of the organs of Impressibility, and the general predominance of the frontal and coronal regions of the brain over the occipital. The qualities already mentioned as favoring impressibility may be studied in the character, or observed in the development, as they occupy the entire anterior half of the head, giving breadth to the temples, with height and projection to the forehead. An enlarged pupil of the eye will be one of the best symptoms, and, in connection with a calm, spiritual, gentle expression of countenance rarely fails to indicate impressibility.

To test impressibility apply the fingers upon the organ of Somnolence, an inch horizontally behind the brow, with a very gentle contact; your subject, after a few minutes, will manifest a sensitiveness of the eye, and will wink oftener than usual—his winking will be repeated and prolonged, until his eyelids droop or remain closed—he is now somnolent and dreamy; and this condition may be prolonged until it becomes the Mesmeric Somnolence, or may be promptly removed by brushing the excitement off with the fingers.

A very simple test of impressibility consists in passing the ends of the fingers over the palm of the hand of the subject, within one or more inches, and ascertaining whether he can recognize its passage by any impression. If impressible he will perceive a cooling sensation as the fingers pass. A more perfect demonstration is to let your subject stand erect before you, and apply both hands gently over the forehead and moral organs, or upon the temples; then very slowly withdraw them, and continue this process until you perceive that as your hand is withdrawn, the head seems inclined to follow it as if attracted; some will move thus but an inch or two, others will be drawn forward and compelled to follow you wherever you go, or may be drawn down and prostrated upon the floor. You may accomplish the same upon the back of the head or body—the hand or any other part which is free to move; but the forehead is the best region, because the front lobe is the seat of Impressibility, and the operation cultivates that quality, by drawing excitement into the brain, and especially the front lobe, thus debilitating the muscular system and power of resistance.

Apply the fingers upon the organ of Relaxation, below the cheek bone, and your subject, if standing, will become enfeebled, unsteady in attitude, and incapable of supporting as great weight as before in his extended hand. This will be counteracted by touching the region of Energy.

The most painful experiments may be made by placing the hands upon the temples and face, so as to cover the regions of Sensibility, Disease, Relaxation, and Irritability—the effect of which would be to produce bodily weakness, sickness, pain, distress and general prostration; a condition, which if not relieved, might result in severe disease, but which may be counteracted by dispersing the excitement upward and backward, and by stimulating Health, Energy and Hardihood.

By grasping a metallic rod firmly in the hand while the other end of it rests in the relaxed hand of an impressible person, you may transmit a current of nervaura, which he will recognize gradually entering his arm at the hand, passing slowly up to the shoulder, and then diffusing itself over the body.

One may test his own impressibility by placing the palm of the hand in contact with any portion of the head or body of a vigorous constitution for about twenty minutes, and observing the different impressions imparted by different localities. If the hand be held in contact with an individual suffering from some active form of disease, resting upon the forehead or the pit of the stomach, the morbid symptoms will be very perceptibly transferred to any one of an impressible constitution; but I would not recommend the experiment to any but those who are embarrassed by a constitutional scepticism, which hinders their believing anything which is not impressed upon their own senses.

An easy method of testing our susceptibility is by holding some active medicinal substance between the hands while sitting at ease (without knowing what the properties of the substance are), and holding other active substances at different times, to compare the effects which they produce upon the constitution. After such experiment, if the effects should in any case be greater than we desire, the influence should be removed by dispersive passes on the hands and down the arms.