The sympathetic ganglia of the chest correspond in number with the terminations of the ribs, over which they are situated. Each ganglion receives two filaments from the intercostal nerve, situated above it, thus forming a double connection. The thoracic ganglia supply with motor fibres that portion of the aorta which is above the diaphragm, the esophagus, and the lungs.
In the abdomen the sympathetic centers are situated upon thecoeliacartery, and are termed, collectively, thesemilunarcoeliac ganglion. Numerous inosculating branches radiate from this center and are called, from the method of their distribution, thesolar plexus. From this, also, originate other plexi which are distributed to the stomach, liver, kidneys, intestines, spleen, pancreas, supra-renal glands, and to the organs of generation. Four other pairs of abdominal ganglia connected with, the lumbar branches are united by filaments to form the semilunar ganglion.
The sympathetic ganglia of the pelvis consist of five pairs, which are situated upon the surface of the sacrum. At the extremity of the spinal column this system terminates in a single knot, designated as theganglion impar.
Owing to the position of the sympathetic ganglia, deeply imbedded in the tissues of the chest and abdomen, it is exceedingly difficult to subject them to any satisfactory experiments. A few isolated facts form the basis of all our knowledge concerning their functions. They give off both motor and sensory filaments. The contraction of theirisis one of the most familiar examples of the action of the sympathetic system.
In the reflex actions of the nerves of special sense, the sensation is transmitted through the cerebro-spinal system, and the motor impulse is sent to the deep-seated muscles by the sympathetic system. Physiologists enumerate three kinds of reflex actions, which are either purely sympathetic, or partially influenced by the cerebro-spinal system. Dr. Dalton describes them as follows:
First.—"Reflex actions taking place from the internal organs, through the sympathetic and cerebro-spinal systems, to the voluntary muscles and sensitive surfaces.—The convulsions of young children are often owing to the irritation of undigested food in the intestinal canal. Attacks of indigestion are also known to produce temporary amaurosis [blindness], double vision, strabismus, and even hemiplegia. Nausea, and a diminished or capricious appetite, are often prominent symptoms of early pregnancy, induced by the peculiar condition of the uterine mucous membrane."
Second.—"Reflex actions taking place from the sensitive surfaces, through the cerebro-spinal and sympathetic systemsto the involuntary muscles and secreting organs.—Imprudent exposure of the integument to cold and wet, will often bring on a diarrhea. Mental and moral impressions, conveyed through the special senses, will affect the motions of the heart, and disturb the processes of digestion and secretion. Terror, or an absorbing interest of any kind, will produce a dilatation of the pupil, and communicate in this way a peculiarly wild and unusual expression to the eye. Disagreeable sights or odors, or even unpleasant occurrences, are capable of hastening or arresting the menstrual discharge, or of inducing premature delivery."
Third.—"Reflex actions taking place through the sympathetic system from one part of the body to another.—The contact of food with the mucous membrane of the small intestine excites a peristaltic movement in the muscular coat. The mutual action of the digestive, urinary, and internal generative organs upon each other takes place entirely through the medium of the sympathetic ganglia and their nerves. The variation of the capillary circulation in different abdominal viscera, corresponding with the state of activity or repose of their associated organs, are to be referred to a similar nervous influence. These phenomena are not accompanied by any consciousness on the part of the individual, nor by any apparent intervention of the cerebro-spinal system."
The eye is the organ through which we perceive, by the agency of light, all the varied dimensions relations, positions, and visible qualities of external objects.
The number, position, and perfection of the eyes, vary remarkably in different orders, in many instances corresponding to the mode of life, habitation, and food of the animal. A skillful anatomist may ascertain by the peculiar formation of the eye, without reference to the general physical structure, in what element the animal lives. Sight is one of the most perfect of the senses, and reveals to man the beauties of creation. The æsthetic sentiment is acknowledged to be the most refining element of civilized life. Painting, sculpture, architecture, and all the scenes of nature, from a tiny way-side flower to a Niagara, are subjects in which the poet's eye sees rare beauties to mirror forth in the rhythm of immortal verse.
In the vertebrates, the organs of vision are supplied with filaments from the second pair of cranial nerves. In mammalia, the eyes are limited to two in number, which in man are placed in circular cavities of the skull, beneath the anterior lobes of the cerebrum. Three membranes form the lining of this inner sphere of the eye, called respectively the Sclerotic, Choroid, and Retina.
TheSclerotic, or outer covering, is the white, firm membrane, which forms the larger visible portion of the eyeball. It is covered in front by a colorless, transparent segment, termed thecornea, which gives the eye its lustrous appearance. Within the sclerotic, and lining it throughout, is a thin, dark membranetermed theChoroid. Behind the cornea it forms a curtain, called theiris, which gives to the eye its color. The muscles of the iris contract or relax according to the amount of light received, thus enlarging or diminishing the size of the circular opening called thepupil. TheRetinais formed by the optic nerve, which penetrates the sclerotic and choroid and spreads out into a delicate, grayish, semi-transparent membrane. The retina is one of the mostessentialorgans of vision, and consists of two layers. A spheroidal, transparent body, termed thecrystalline lens, is situated directly behind the pupil. It varies in density, increasing from without inward, and forms a perfect refractor of the light received. The space in front of the crystalline lens is separated by the iris into two compartments called respectively theanteriorandposterior chambers. The fluid contained within them, termed theaqueous humor, is secreted by the cornea, iris, and ciliary processes. The space behind the crystalline lens is occupied by a fluid, called thevitreous humor. This humor is denser than the other fluids and has the consistency of jelly, being perfectly transparent. "The function of the crystalline lens is to produce distinct perception of form and outline."[3]The transparent humors of the eye also contribute to the same effect, but only act as auxiliaries to the lens.
Illustration: Fig. 62.Fig. 62.
The figure on the next page represents the course of the rays of light proceeding from an objecta b, refracted by the lens, and forming the inverted imagex yon the screen. All rays of light proceeding frombare concentrated aty, and those proceeding fromaconverge atx. Rays of light emanating from the center of the objecta bpursue a parallel course,and form the center of the image. Rays of light passing through a double convex lens converge at a point called thefocus. In the organ of vision, if perfect, the focus is on the retina, which serves as a screen to receive the image or impression. We have a distinct perception of the outline of a distant hill, and also of a book lying before us. The rays of light we receive from these objects cannot have the same focus. How, then, can we account for the evident accommodation of the eye to the varying distances? Various theories have been advanced to explain this adjustment; such as changes in the curvature of the cornea and lens; a movement of the lens, or a general change in the form of the eyeball, by which the axis may be lengthened or shortened.
Illustration: Fig. 63.Fig. 63.
Two facts comprise all the positive knowledge which we possess on this subject. Every person is conscious of a muscular effort in directing the eye to a near object, as a book, and of fatigue, if the attention is prolonged. If, now, the eyes be directed to a distant object, there will result a sense of rest, or passiveness. By various experiments it has been proved that the accommodation or adjustment of the eye for near objects requires a muscular effort, but for distant objects the muscles are in an essentially passive condition. An increase in the convexity of the crystalline lens is now admitted to be necessary for a distinct perception of near objects. We may give two simple illustrations, cited by Dr. Dalton in his recent edition of Human Physiology. If a candle be held near the front of an eye which is directed to a distant object, three reflected images of the flame will be seen in the eye, one on each of the anterior surfaces of the cornea and lens, and a third on the posterior surface of the latter. If the eye is directed to a near object, the reflection on the cornea remains unchanged, while that on the anterior surface of the lens gradually diminishes and approximates in size the reflection on the cornea, thus giving conclusive evidence that, in viewing a near object, the anterior surface of the crystalline lens becomemore convex, and atthe same time approaches the cornea. Five or six inches is the minimum limit of the muscular adjustment of the eye. From that point to all the boundless regions of space, to every star and nebulæ which send their rays to our planet, human vision can reach. It is the sense by which we receive knowledge of the myriads of worlds and suns which circle with unfailing precision through infinite space.
Illustration: Fig. 64. Internal and external ear.Fig. 64. Internal and external ear.1.External ear.2.Internal auditory meatus.3.Tympanum.4.Labyrinth.5.Eustachian tube.
Hearing depends upon the sonorous vibrations of the atmosphere. The waves of sound strike the sensitive portions of the ear, and their impressions upon the auditory nerves are termed the sensations of hearing. The ear is divided into three parts, called respectively the External, Middle, and Internal ear.
The external organs of hearing are two in number, and placed on opposite sides of the head. In most of the higher order of vertebrates, they are so situated as to give expression and proportion to the facial organs, and, at the same time, to suit the requirements of actual life.
TheExternal earis connected with the interior part by a prolongation of its orifice, termed theexternal auditory meatus. In man, this gristly portion of the auditory apparatus is about one inch in length, lined by a continuation of the integument of the ear, and has numerous hairs on its surface, to prevent the intrusion of foreign substances. Between the externalmeatusand the cavity of the middle ear is themembranatympani, which is stretched across the opening like the head of a drum. Thetympanum, or ear-drum, communicates with the pharynx by theeustachian tube, which is a narrow passage lined with delicate, ciliated epithelium. On the posterior portion it is connected with themastoid cells. Three small bones are stretched across the cavity of the tympanum, and called, from their form, themalleus, incusandstapes, or the hammer, anvil, and stirrup. Agassiz mentions a fourth, which he terms theos orbiculare. Each wave of sound falling upon the membrana tympani, throws its molecules into vibrations which are communicated to the chain of bones, which, in turn, transmits them to the membrane of theforamen ovale. The three muscles which regulate the tension of these membranes are termed thetensor tympani, laxator tympani, andstapedium tympani.
TheLabyrinth, orInternalear, is a complicated cavity, consisting of three portions termed thevestibule, cochlea, andsemi-circular canals. The vestibule is the central portion and communicates with the other divisions. The labyrinth is filled with a transparent fluid, termedperilymph, in which are suspended, in the vestibules and canals, small membranous sacs, containing a fluid substance, termedendolymph(sometimes calledvitrine auditivefrom its resemblance to the vitreous humor of the eye). The filaments of the auditory nerve penetrate the membranous tissues of these sacs, and also of those suspended at the commencement of the semi-circular canals. These little sacs are supposed to be the seat of hearing, and to determine, in some mysterious way, the quality, intensity and pitch of sounds.
The determination of thedirectionof sound is a problem of acoustics. Some have contended that the arrangement of the semi-circular canals is in some way connected with this sensation. But this supposition, together with the theory of the transmission of sound through the various portions of the cranial bones, has been exploded.
From the foregoing description, it will be seen that the labyrinth and tympanum are the most essential parts of the organs of hearing. In delicacy and refinement this sense ranks next to sight. The emotions of beauty andsublimity, excited by the warbling of birds and the roll of thunder, are scarcely distinguishable from the intense emotions arising from sight. It is a remarkable fact, that the refinement or cultivation of these senses is always found associated. Those nations which furnish the best artists, or have the highest appreciation of painting and sculpture, produce the most skillful musicians, those who reduce music to a science.
Illustration: Fig. 65.Fig. 65.1.Frontal sinus.2.Nasal bone.3.Olfactory ganglion and nerves.4.Nasal branch of the fifth pair.5.Spheno-palatine ganglion.6.Soft palate.7.Hard palate,a. Cerebrum,b. Anterior lobes,c. Corpus callosum.d. Septum lucidum.f. Fornix.g. Thalami optici.h. Corpora striata.
Next in order of delicacy, and more closely allied with the physical functions, is the sense of smell. Delicate perfumes, or the fragrance of a flower, impart an exhilarating sensation of delight, while numerous odors excite a feeling of disgust. The organ of smell is far less complicated in its structure than the eye or the ear. It consists of two cavities having cartilaginous walls, and lined with a thick mucous coat, termed thepituitary membrane, over which are reflected the olfactory nerves. Particles of matter, too minute to be visible even through the microscope, are detached from the odorous body and come in contact with the nerves of smell, which transmit the impressions or impulses thus received to the brain. Fig. 65 shows the distribution of the olfactory nerves in the nasal passages. The nose is supplied with two kinds offilaments which are termed respectively nerves ofspecialand nerves ofgeneral sensation. Compared with the lower animals, especially with those belonging to the carnivorous species, the sense of smell in man is feeble. The sensation of smell is especially connected with the pleasures and necessities of animal life.
The sense of taste is directly connected with the preservation and nutrition of the body. A delicious flavor produces a desire to eat a savory substance. Some writers on hygiene have given this sense an instinctive character, by assuming that all articles having an agreeable taste are suitable for diet. The nerves of taste are distributed over the surface of the tongue and palate, and their minute extremities terminate in well developedpapillæ. Thesepapillæare divided into three classes, termed, from their microscopic appearance,filiform,fungiformandcircumvallate. The organ of taste is the mucous membrane which covers the back part of the tongue and the palate. The papillæ of the tongue are large and distinct, and covered with separate coats of epithelium. The filiform papillæ are generally long and pointed and are found over the entire surface of the tongue. The fungiform are longer, small at the base and broad at the end. The circumvallate are shaped like an inverted V and are found only near the root of the tongue; the largest of this class of papillæ have other very small papillæ upon their surfaces. It is now pretty satisfactorily established that the circumvallate, or fungiform papillæ are the only ones concerned in the special sense of taste.
The conditions necessary to taste are, that the substance be in solution either by artificial means, or by the action of the saliva; and that it be brought in contact with the sensitive filaments imbedded in the mucous membrane. The nerves of taste are bothgeneralandspecialin their functions. If the general sensibility of the nerves of taste is unduly excited, the function of sensibility is lost for some time. If a peppermint lozenge is taken into the mouth, it strongly excites the general sensibilities of taste, and the power of distinguishing between special flavors is lost for a few moments. Anauseous drug may then be swallowed without experiencing any disagreeable taste.
Paralysis of the facial nerve often produces a marked effect in the sensibility of the tongue. Where this influence lies has not been fully explained; probably it is indirect, being produced by some alteration in the vascularity of the parts or a diminution of the salivary secretions.
By the sense of touch, we mean thegeneral sensibility of the skin. Sensations of heat and cold are familiar illustrations of this faculty. By the sense of touch, we obtain a knowledge of certain qualities of a body, such as form consistency, roughness, or smoothness of surface, etc. The tip of the tongue possesses the most acute sensibility of any portion of the body, and next in order are the tips of the fingers. The hands are the principal organs of tactile sensation. The nerves of general sensibility are distributed to every part of the cutaneous tissue. The contact of a foreign body with the back, will produce a similartactilesensation, as with the tips of the fingers. The sensation, however, will differ indegreebecause the back is supplied with a much smaller number of sensitive filaments; inqualityit is the same.
By means of the nervous system, an intimate relation is maintained between mind and body, for nervous energy superintends the functions of both. The fibres of nervous matter are universally present in the organization, uniting the physical and spiritual elements of man's being. Even the minutest nerve-rootlets convey impressions to the dome of thought and influence the intellectual faculties. We recognizemuscularforce, the strength of the body,molecularforce, molecules in motion, as heat, light, chemical force, electricity, andnervousforce, a certain influence which reacts between the animal functions and the cerebrum, thus connecting the conditions of the body with those of the mind. We cannot speak of the effects of mind or body separately, but we must consider their action and reaction upon each other, for they are always associated. There are many difficulties in understanding this relationship, some of which may be obviated by a study of the development of nervous matter, and its functions in the lower orders of organization.
Within the plant-cells is found a vital, vegetable substance termed bioplasm, or protoplasm; which furnishes the same nutritive power as the tissues of the polyp and jelly fish. Many families of animals have pulpy bodies, and slight instinctive motion and sensibility, and in proportion as the nervous system is developed, both of these powers are unfolded. Plants have a low degree of sensibility, limited motion, respiratory and circulatory organs. Animals possess quicker perceptions and sensibilities, the power of voluntary motion, and, likewisea rudimental nervous system. Some articulates have no bony skeleton, their muscles being attached to the skin which constitutes a soft contracting envelope. One of the simplest forms of animal life in which a nervous system is found, is the five-rayed star-fish. In each ray there are filaments which connect with similar nerve-filaments from other rays, and form a circle around the digestive cavity. It probably has no conscious perception, and its movements do not necessarily indicate sensation or volition. In some worms a rudimentary nervous system is sparingly distributed to the cavities of the thorax and abdomen, and, as in the star-fish, the largest nerve-filament is found around the esophagus, presiding over nutrition.
Illustration: Fig. 66.Fig. 66.
A higher grade of organization requires a more complete arrangement of nervous substance. Stimulus applied to one organ is readily communicated to, and excites activity in another.
Illustration: Fig. 67.Fig. 67. A. Nervous system of a Crab, showing its ganglia. B. The nervous system of a Caterpillar.
The nervous system of some insects consists of two long, white cords, which run longitudinally through the abdomen, and are dilated at intervals into knots, consisting of collections of nerve-cells, called ganglia. They are really nerve-centers, which receive and transmit impulses, originate and impart nervous influence according to the nature of their organic surroundings. The ganglia situated over the esophagus of insects correspond to the medulla oblongata in man, in which originate the spinalaccessory, glosso-pharyngeal, and pneumogastric nerves. The latter possess double endowments, and not only participate in the operations of deglutition, digestion, circulation, and respiration, but are also nerves of sensation and instinctive motion. The suspension of respiration produces suffocation. In insects, these ganglia are scarcely any larger than those distributed within the abdomen, with which they connect by means of minute, nervous filaments. Insects are nimble in their movements, and manifest instinct, corresponding to the perfection of their muscular and nervous systems. When we ascend to vertebrates, those animals having a backbone, the amount of the nervous substance is greater, the organic functions are more complex, and the actions begin to display intelligence.
Man possesses not only a complete sympathetic system, the rudiments of which are found in worms and insects, and a complete spinal system, less perfectly displayed in fishes, birds, and quadrupeds, but, superadded to all these is a magnificent cerebrum, and, as we have seen, all parts of the body are connected by the nervous system. The subtle play of sensory and motor impulses, of sentient and spiritual forces, indicates a perfection of nervous endowments nowhere paralleled, and barely approached by inferior animals. This meager reference to brainless animals, whoso knots of ganglia throughout their bodies act automatically as little brains, shows that instinct arises simultaneously with the development of the functions over which it presides. Here begins rudimentary, unreasoning intelligence. It originates within the body as an inward, vital impulse, is manifested in an undeviating manner, and therefore displays no intention or discretion. While Dr. Carpenter likens the human organism "to a keyed instrument, from which any music it is capable of producing can be called forth at the will of the performer," he compares "a bee or any other insect to a barrel organ, which plays with the greatest exactness a certain number of tunes that are set upon it, but can do nothing else." Instinct cannot learn from experience, or improve by practice; but it seems to be the prophetic germ of a higher intelligence. It is nearly as difficult to draw the dividing line between instinct and a low grade of intelligence, as it is to distinguishbetween the psychical and psychological[4]functions of the brain.
The intimate relation of instinct to intelligence is admirably illustrated in the working honey-bee. With forethought it selects a habitation, constructs comb, collects honey, provides a cell for the ova, covers the chrysalis, for which it deposits special nourishment, and is disposed to defend its possessions. It is a social insect, lives in colonies, chastises trespassers, fights its enemies, and defends its home. It manifests a degree of intelligence, but its sagacity is instinctive. Reason, though not so acute as instinct, becomes, by education, discerning and keenly penetrative, and reveals the very secrets of profound thought. We recall the aptness of Prof. Agassiz's remark:"There is even a certain antagonism between instinct and intelligence, so that instinct loses its force and peculiar characteristics, whenever intelligence becomes developed."Animals having larger reasoning powers manifest less instinct, and some, as the leopard, exercise both in a limited degree. This double endowment with instinct and low reasoning intelligence, is indicated by his lying in ambush awaiting his prey, the hiding-place being selected near the haunt of other animals, where nature offers some allurement to gratify the appetite.
Simple reflex action is an instinctive expression, manifesting an intuitive perception, almost intelligent, as shown by the contraction of the stomach upon the food, simply because it impinges upon the inner coats, and thus excites them to action. A better illustration, because it displays sympathy, is when the skin, disabled by cold, cannot act, and its duties are largely performed by the kidneys. Though reflex action is easily traced in the lower organic processes, some writers have placed it on a level with rational deliberation. Undoubtedly, all animals having perception have also what perception implies—consciousness—and this indicates the possession, in somedegree, of reason.Compoundreflex action extends into the domain of thought.Simplereflex action, or instinct, answers to the animal faculties, such as acquisitiveness, secretiveness, selfishness, reproductiveness, etc., and accomplishes two important purposes; self-preservation and the reproduction of the specie. With many persons, these appear to be the chief ends of life!
The psychical functions connect, not only with animal propensities, but also with the highest psychological faculties. Instinct is the representative of animal conditions, just as the highest spiritual faculties are indicative of qualities and principles. The consistent mean of conduct is an equilibrium between these ultimate tendencies of our being. The psychological functions render the animal nature subservient to the rule of purity and holiness, and deeply influence it by the essential elements of spiritual existence. The psychical organs sustain an intermediate relation, receiving the impressions of the bodily propensities, and, likewise, of the highest emotions. Obviously, these extreme influences, the one growing out of animal conditions, the other, the result of spiritual relations, pass into the psychical medium and are refracted by it, or made equivalent to one force. The body requires the qualifying influences of mind. The tendencies of the animal faculties are selfish and limiting, those of the emotive, general, universal. The propensities, like gravity, expend their force upon matter; the emotions pour forth torrents of feeling, and produce rhapsodies of sentiment. The propensities naturally restrict their expression to a specific object of sense; the emotions respond to immaterial being. The tendencies of the former are acquisitive, selfish, gratifying; of the latter, bestowing, expanding, diffusing. The one class is restricted to the orbits of time and matter, the other flows on through the limitless cycles of infinity and immortality. The former is satiated in animal gratification, the latter in spiritual beatification. The one culminates in animal enjoyment, the other expands to its ultimate conceptions in the perfections of Divine Love.
In the present life, mind and body are intimately connected by nervous matter. In this dual constitution, the spiritual mental, and animal functions are made inseparable, and modifyone another. The ultimate tendencies of each extreme exist, not absolutely for themselves, but for qualifying purposes, to establish a basis for the deeper economy of life. By the employment of reason, animal and spiritual experiences are mutually benefited, and the consciousness rendered accountable. The bodily and mental workings are in many senses one, and help to interpret each other.
Every fact of mind has many aspects. A brain force, which results in thought, is simultaneously a physiological force, if it influences the bodily functions. Likewise, spiritual conceptions take their rise in the same blood that feeds the grosser tissues. This vital fluid is momentarily imparting and receiving elements from all the bodily organs, and these, in turn, must influence the process of thought, and, in a degree, determine its quality. The delicate outline, yea, even the substance of an idea, may depend upon the condition of the animal organs. Thought is subject to the laws of biology, and, therefore, is a symbol of health. Morbid conditions of the system hang out their signs in words and utterances. Words which express fear are as true symptoms of functional difficulty as is excessive palpitation. The organ representing fear sustains a special relation to the functions of the heart both in health and disease. Bright hopes characterize pulmonary complaints as certainly as cough. Exquisite susceptibility of mind indicates equally extreme sensibility of body, and those persons capable of fully expressing the highest emotions are especially susceptible to bodily sensations. Tears are physical emblems of grief, and fellow-feeling calls forth sympathetic tears. Excessive anxiety of mind produces general excitability of body, which soon results in chronic disease. Pleasurable emotions stimulate the processes of nutrition, and are restorative. This concomitance of mental and bodily states is very remarkable. Joy and Love, as well as jealousy and anger, flash in the eye and mould the features to their expression. Grief excites the lachrymal, and rage the salivary glands. Shame reddens the ears, drops the eyelids, and flushes the face; but profligacy destroys these expressions. The blush which suffuses the forehead of the bashful maiden betrays her love, andmaternallove, stirred by the appeals of an idolized infant, excites the mammary glandto the secretion of milk. The sigh of melancholia indicates hepatic torpor, thus showing a special relation between the liver and respiratory organs. These conditions of mind and body react upon one another. Even the thought of a luscious peach may cause the mouth to water. The thought of tasting a lemon fills the mouth with secretions, and a story with unsavory associations may completely turn the stomach.
The relationship of mental and physical functions may be illustrated by entirely removing the spleen of an animal, as that of a dog. An invariable result of its extirpation is an unusual increase of the appetite, for at times the animal will eat voraciously any kind of food. The dog will devour, with avidity, the warm entrails of recently killed animals, and thrive in consequence of such an appetite. Another symptom, which usually follows the removal of the spleen, is an unnatural ferocity of disposition. Without any apparent provocation, the animal will attack others of its own, or of a different species. In some instances, these outbursts of irritability and violence are only occasional, but the experiments show quite conclusively that the spleen moderates combativeness, restrains the appetite, and co-operates with the will and judgment in controlling them.
We shall briefly consider the practical question whether the elements of mind can be ideally arranged and presented, so as to more completely reveal their relations to, and disclose their effects upon the bodily functions. Modern philosophers conceive that mind consists of a triad of essentials;Intellect, Emotion,andVolition. Physiologists assign to the cerebrum its functions, and neurological, as well as phrenological writers, have located them as represented in Fig. 68. True, there is no structural division between the parts of the cerebrum to indicate this diversity of function, nor is there any perceptible limit between the sensory and motor filaments of the game nerve. As no one has any reason for denying that separate portions of the brain may manifest distinct functions of the mind, we shall assume it as a conceded proposition. The regions of the cerebrum, thus ideally represented, occupy but little more than half of the arc of a circle, whereas it is evident that the base of the nervous mass is not idle, and is equally entitled to our consideration. In the posterior chamberof the skull is the cerebellum, anterior to, and below which, is the medulla oblongata, connecting with the spinal cord and sympathetic system. These various parts are essential to the harmonious blending of mind and body. To this end, two conditions are necessary. (1.) All the nervous forces must be so related that action and reaction may be fully established. (2.) A complete nervous circuit is requisite for the reciprocal influence of mind and body.
Illustration: Fig. 68.Fig. 68.
Illustration: Fig. 69.Fig. 69.
Nature answers to mind in physical correspondences. The planetary system is fashioned after a circle. Life itself springs from a spherule of forces. The perfection of an idea, or the completeness of a conception may be expressed by a circle. The elements of Science, Astronomy, Geology, and Natural History, are pictorially represented in this manner. How appropriately and logically can a fragment of natural history, this epitome of all nature and science—the mind—be illustrated by a simple circle! Every element must act and react, and be equal and opposite. Thus may the existence of the opposing energies and functions of each faculty be equally represented. The contrast aids us in understanding their ultimate tendencies, and enables us to correctly value and define their nature. Faculties of kindred qualities may be grouped together, and their antagonisms represented in the opposite arc of the circle. Let us employ a circle to represent mind. The conception of the abstractquality ofgood, requires contrast with one of a converse nature,bad, (see Fig. 69). Opposite faculties may be portrayed in the same manner. The functions of the cerebrum and spinal system may be symbolically represented as those of the highest and lowest organs, thus giving rise to the positive and negative extremes of feeling. The writer conceives of no other way in which the widely contrasted facts of human experience can be so perfectly symbolized.Good(Fig. 69) may represent moral faculties, andbad, their opposites. Undoubtedly, nature is not so arbitrary in her arrangements as we are in shadowing forth our imperfect conceptions, yet is not this a decided improvement in determining cerebral faculties and their relations? We observe how scholars and philosophers confound the noblest and most exalted emotions with the animal propensities instead of distinguishing between them. "The emotions are a department of the feelings, formed by the intervention of intellectual processes. Several of them are so characteristic that they can be known only by individual experiences; as Wonder, Fear, Love, Anger." See Logic: Deductive and Inductive, by Alexander Bain, LL. D., page 508, (1874).
This is not an exceptional, but a common example of classifying Love, the highest and purest of the emotions, with Anger, an animal propensity. Is it not more practical and philosophical to group the emotional faculties together, and upon an opposite arc represent their antagonistic energies, the ultimate tendencies of which are criminal? Both groups are mutually modifying and restraining; the one relates instinctively to the bodily wants, the other to the requirements of mind, and each is essential to a consistent life. Accordingly, we deem it philosophical to consider words as symbols of mental faculties, and to classify together such spiritual unities as joy, hope, faith, and love, the tendencies of which are to quicken and transform the ultimates of carnal life into the rudiments of an immortal one, the beginning of heaven on earth. These restrain those opposites, which lead to crime and death. Love and Hate are as antagonistic as heat and cold, and the usefulness of both depends upon theirpropertemperament. Fig. 70 represents the antagonism of the Intellectualfaculties to the Animal, the Emotional to the Criminal, the Volitive to the Enfeebling. It is not essential to discover in the nerve-substance the precise power from which an impulse originates. We may reasonably interpret the functions of the brain, and yet be unable to disclose the duties of any ganglionic corpuscle composing it. We may foretell what each season of the year will bring forth, when we cannot forecast the history of a blade of grass or a single grain of any kind. We may predict the amount of rain for a month, and be unable to prognosticate correctly, the character of any storm, or give the history of a special drop of water. Although we cannot follow the movements of individuals in a battle, yet we may predict the result of the combat; and thus, we judge of the functions of the brain without the ability to reveal the actions of one of the organic molecules of which it is composed. We aim to give a general, reasonable, and popular description of cerebral functions and their bearing upon health and disease.
Illustration: Fig. 70.Fig. 70.
Illustration: Fig. 71.Fig. 71.
The anterior portion of the cerebrum is devoted to intellectual processes, which freely expend the vital energies. The Intellectual faculties are classified as represented in Fig. 71. The lower portion of the brain, bounded exteriorly by the superciliary ridge, corresponds to the Perceptive, the middle region to the Recollective, and the upper to the Reflective faculties. (See also Fig. 65,b.) If we divide the forehead by vertical lines, as shown in Fig. 71, the divisions thus formed represent respectively, the Active, Deliberative, and Contemplative departments of the intellect, all the processes of which are sustained by vital changes, the transformation of organized materials. No mental effort can be made without waste ofnervous matter. The gardener's hoe wears by use, and so does every part of the animal organism. Otherwise, nutrition would be unnecessary for the adult. The production of thought wears away the cerebral substance. In ordinary use, the brain requires one-fifth of the blood to support its growth and repair. Great mental efforts are attended by a corresponding expenditure of vital treasures, which are abstracted from the total forces available for the necessities of the system. To repair the losses thus occasioned, materials are appropriated from the blood, which furnishes supplies in proportion to the demands made by the mental activities. The production of thought wears away the gray matter of the cerebrum as surely as the digging of a canal wears away the iron particles of the spade. The brain would soon wear out did not the nutritive functions constantly make good the waste. The intellect, whether engaged in observation, generalization, or profound study consumes the brain and blood, hence intellectual activity implies VITAL EXPENDITURE.Expenditureis an emphatic word because all functions are essential to the production of this nerve-energy, which returns to the system no equivalent. Physical exercise, although attended by structural waste, is advantageous to the circulation of the blood, nutrition, secretion, and, in fact, beneficial to all the organic processes. This is not true of vigorous and prolonged mental labor, which is not attended by any of these incidental advantages. If a child attends a school in which mental development supersedes physical culture, an inordinate ambition sways the youthful mind, andits baneful effects upon the health soon become manifest. Rigorous application of the intellectual faculties consumes the blood, exhausts the vital forces, weakens the organic functions, while pallor covers the face, and the eyes sparkle with a hectic radiance. The family physician pronounces the conditionAnæmia(a deficiency of red corpuscles in the blood), and this change in the quality of the blood is owing to the undue appropriation by the brain. Conversely, if the blood be destroyed, or its vitality reduced, in the same proportion will the mental energies be weakened and all the functional powers of the physical system enfeebled. In brief, if the intellect be unduly exercised, the red corpuscles of the sanguine fluid will be gradually destroyed, and the serum allowed to predominate. The blood becomes weak and watery, the subject is nervous, dropsical, consumptive and derangement of the important functions follows almost invariably. Excessive intellectual activity often produces weak state of the system, and the person thus affected becomes languid, spiritless, and an easy prey to disease. This mental cause and its bodily results may be classified in the following order. Mental Cause: EXCESSIVE MENTAL EXERTION, which produceswaste of the brain substance and blood.
This kind of waste is best summed up in the words, VITAL EXPENDITURE. Upon the forehead, as represented in Fig. 72, we will therefore inscribe INTELLECT, ACTIVITY, and VITAL EXPENDITURE. Intellectual employment is usually accompanied by sedentary habits, neglect of healthful exercise, and a deprivation of pure air, to all of which ill health may be attributed. Were the intellectual expenditure arrested, and the forces turned into recuperative channels, many a person would become beautiful with the ruddy glow of health. Without health there is no use for thought; cultivation of the mind is just as natural and essential as the culture of the body, and the trained development of both is needed for mutual improvement.
Illustration: Fig. 72.Fig. 72.
What results follow thenaturaland theexcessiveexercise of the EMOTIVE FACULTIES? AS distinct organs of the body have diverse functions, so, in like manner, different parts of the brain perform the separate operations of the mind. It is easier to discriminate between the products of these dissimilar endowments than to determine the location of the faculties. The intellect deals with concrete subjects, and the emotions with abstractions; the intellect is exercised with material things, the emotions dwell upon attributes; the intellect considers the forces of matter, the emotions, the powers ofthe soul; the former deliberates upon the truths of science, the latter is concerned with duties, obligations, or moral responsibilities; the first is satisfied only with new truths, original ideas, and rational changes, the last rest securely on fundamental principles, moral certainties, and the absolute constancy of perfect love. The intellectual faculties are wakeful, questioning, mistrustful; the emotions are blind, hopeful, confiding; the one reasoning, exacting, demonstrating; the other, believing, inspiring, devout. The intellect sees, the emotions feel; and, though these functions may blend, the one can never supersede the other.
The quality of the emotional faculties is represented by Benevolence, Sympathy, Joy, Hope, Confidence, Gratitude, Love, and Devotion, all of which are the very antitheses of the attributes of animal feeling, described as Melancholy, Fear, Anger, Hate, Malevolence, and Despair. To the emotions we refer the highest qualities of character, while their opposites represent the animal or baser impulses. True, the emotions modify the propensities, as sympathy softens grief. They may subdue and refine the animal feelings, and thus veil them with a delicacy characteristic of their own purity; but the unrestrained influences of grief find vent in loud lamentations, and the bitter disappointments of the selfish faculties are passionate and violent.
TheEmotive Faculties—the organs of spiritual perceptions—are impersonal, outflowing, bestowing. The function represented by Benevolence, is willing, giving. Devotion expresses dedication, consecration; Gratitude manifests a warm and friendly feeling toward a benefactor.
"The depth immense of endless gratitude."—MILTON.
"The depth immense of endless gratitude."—MILTON.
Love flames toward its object, is out-pouring, blessing; indeed, all the emotions are gushing, effusive, impetuous, and profusely flowing; grand, torrent-like, overwhelming; employing ideal, immaterial, spiritual expressions, developing principles and perfections while aspiring to happiness and immortality. Though beginning with humanity, they embody the Divine. They expand to their ultimate conceptions in the sublime attributes: the perfections of the God of Love; associatingwith mortality a divine destiny commencing on earth, extending through time, pausing not at the portals of death, the gateway to eternity, but flowing onward into the realms of eternal day.
We may consider their counteracting influences, for, without doubt, by checking the selfish tendencies and restraining the animal propensities, they assist in controlling the sensual passions, and thus balance the mind and body. Such an equilibrium we callhappiness. If the emotions be acute and vehement, they will absorb all other impressions and revel in their culminating and delightful experiences. They exhaust all the bodily energies, and a functional suspension, termedecstasy, follows. It is a swooning, or fainting, a temporary loss of sensation and volition, accompanied by involuntary movements of the arms, smiting of the hands, sighing, and short ejaculatory expressions of rapture. This condition, occasioned by excessive emotion, as in praying, singing, exhortations, and sympathetic appeals, is contagious, often spreading with mysterious rapidity. Its culmination, ecstasy, is popularly termed "the power." When gradually induced, it is calledtrance, and each state is regarded by many as supernatural, caused by the immediate influence of the Holy Spirit. The explanation is this: when the emotive faculties are suddenly and powerfully excited, they quickly expend the organic forces, so that the individual swoons from sheer exhaustion. Undue expenditure of this class of brain functions not only consumes the bodily powers, but exhausts and prevents other mental operations. The sudden collapse of all voluntary functions resembles the fainting produced by blood-letting. We may sum up this rapid expenditure of energy in one expressive word, EXHAUSTION, which results inEcstasy, or trance, and which, if carried a degree further, terminates in death. Beginning with the natural exercise of the emotions, we may state the order of sequences thus:
What are the physiological and morbid results attending the ordinary and the immoderate exercise of the VOLITIVE FACULTIES?
The generic termwill, comprehends those faculties, the action of which is termedvolition. The faculties of the will are Determination, Firmness, Decision, Ambition, Authority, and Vigilance, all of which indicate strength and continuity of purpose. Bordering upon the emotions are Patience and Perseverance, while adjoining the animal faculties are Power, Coarseness, and Love of Display. The former exhibit moral, the latter animal heroism. A sense of power urges forward, whether it be higher or lower, just as the sense of greatness makes a mangreatby inspiring him with confidence to put forth exertion. Nature is truthful in her aspirations. We know that courage, assurance, and conscious power are necessary for the fulfillment of purpose, because intention precedes action. Will-power is an indication of HEALTH, and the constant exercise of these mental faculties exerts a steady, regular, and strengthening influence over the bodily functions. We translate mental energies into physiological industry. These faculties impart tone to the system, sustain the processes of nutrition, circulation, assimilation, secretion and excretion, and their distinguishing characteristics are vigor, tension, and elasticity. They temper each element of character, as well as every vital act. They infuse the organism with a resisting power which renders it proof against the influence of miasma and malaria, and overcomes that passivity and impressionability so favorable to disease. Firmness expresses a physiological cohesiveness which strongly binds together the fibers of the tissues, and renders the organization compact and powerful. He, who can skillfully employ these energies, is already master of half of the diseases incident to mankind, and wields an indispensable adjunct to medicine, in the practice of the healing art. It is the key to success, for it unlocks difficulties and opens wide the door which leads to favorable results.
Surplus energy sustains the circulation, increases capillary action, as if the excess of nerve-power were discharged fromthe distant extremity of each nerve and pervaded every tissue. The voluntary muscles indicate their participation in this energy, and, indeed, the whole organism is exalted by the influence of the mental faculties. They oppose the tendencies of Feebleness, Relaxation, and Derangement, and modify their proclivities to Disease. The will is the servant of the intellect, emotions, and propensities, and the executive agent of all the faculties. When the volitive faculties are in excess, they may overdo the other functions, prematurely break down the bodily organs, and, by overtaxing the system, subject it to pain and disorder.
The natural effect of FIRMNESS is physiological stability. The exercise of the volitive faculties displays both mental and bodily ENERGY.
Illustration: Fig. 73. is a representation of the cranial conformation of Alexander VI.,Fig. 73. is a representation of the cranial conformation of Alexander VI., exhibiting a full development of the conservative faculties. His character, according to history, brought reproach upon the papal chair.
Illustration: Fig. 74. represents Zeno, a profound thinker and moral philosopher.Fig. 74. represents Zeno, a profound thinker and moral philosopher. The contrast in their cranial developments was no greater than that of their lives.
Under this generic term we will group those cerebral powers which are common to the inferior animals, and closely allied to bodily conditions and necessities. As denoting a group of animal faculties they relate not only to the organic functions and self-preservation, but combat the action of the intellect,oppose the evolution of new ideas, resist investigation, and discredit the value of truth. Adhesiveness, being blindly conservative, clings to old ideas and traditionary opinions. The animal faculties tend to stifle investigation, and put authority above truth and science. Having a fixity of nature, a stationary attachment, they treat all intellectual developments as absurd. When these faculties predominate, thought is obscured, intolerance of disposition is manifested, and mental progress is arrested. Thus they evince their conservative nature, and, since they relate to individual interests, they represent the elements of instinct. Such are the functions of Acquisitiveness, Secretiveness, Selfishness, and Combativeness, as well as the Generative powers. If these faculties predominate, all intellectual advancements are treated as experiments or theoretical novelties, and rejected as evanescent and worthless. If the promptings of these be followed, there will be no innovation, and the orthodoxy of the dark ages will remain the standard for all time. The animal faculties coincide with Lethargy, Sleep, and Nutrition, thus favoring organic restoration. The intellectual faculties are wakeful, active, irrepressible, while the animal powers tend to repose, sleep, and renovation, and thus suspend the activities of thought, sense, and motion. The intellect expends the energy of the sensorial centers, induces fatigue and suffering, whereas the animal faculties overcome the vigils of thought, and produce refreshing slumber. Dr. Young styles sleep "tired nature's sweet restorer." Swedenborg declared that, "in sleep the brain folded itself up, and the soul journeyed through the body, repairing the wastes of the previous day." When sleep is natural, the insane are in a fair way to recovery, the sick become convalescent, ulcers granulate, and lesions are made whole.
The animal faculties are skeptical, stubborn, and dogmatic, readily combining with those of the violent class, the ultimate tendencies of which are criminal. They are likewise conceited, assuming, and clannish. Any person distinguished by them, will cling to old associations, perpetuate the status of existing parties, be a stickler for creed, ceremonies, and stale opinions, and adhere to ancient orthodoxy in medicine and religion. The animal faculties, since they are staid and regular, are naturallyantagonistic to genius, sensibility, and originality. Their mental tendencies have been fairly described and their physiological results may be represented as follows:
The ultimate tendencies of the faculties, represented by the posterior base of the cerebrum, are violent and criminal. Being contiguous to the junction of the cerebrum and spinal system, they are subject to the influence of animal experiences. A large development of these faculties is indicated by an unusual breadth and depth of the back part of the base of the brain, and a full, thick neck, both of which denote good alimentary and digestive powers. Active nutrition, plethora of the circulation, vigorous secretion, a well developed muscular system, a large heart and lungs, are accessory conditions. We do not associate corpulence or surplus of vitality with a long, slender neck. The character of cerebral manifestations is represented by the baser faculties of mind, such as Combativeness, Destructiveness, Desperation, Turbulence, Hatred, and Revenge. If unrestrained, these culminate in violent and criminal acts; ifregulated, they are employed in personal defense. Whenunduly excited, they lead to dissipation, obscenity, swearing, rowdyism, and licentiousness; whenperverted, they are the source of recklessness, quarrels, frauds, falsehoods, robberies, and homicides. They are unlike instinct, inasmuch as they are not self-limiting. The intimate relation which they sustain to the stomach and nutritive functions is strikingly displayed in the habit of alcoholic intoxication. Spirituous drinks deprave the appetite, derange and destroy the stomach, poison the blood, and pervert all the functions of mind and body; and their injurious influence upon the nerves and basilar faculties is equally remarkable. They excite combativeness, selfishness, irritability, and exaggerate the influence of the animal organs. Intemperance results in disputes, fights, brawls,and murders—the legitimate consequences of which are misunderstandings, suits at law, criminal proceedings, imprisonment, and the gallows. It is, therefore, evident that the ultimate tendencies of these faculties are tyrannical, cruel, violent, and atrocious. They are opposed to the noble, moral faculties—Faith, Love, and Devotion—and, whenever temptation inordinately allures, the course of life is likely to be characterized by dishonorable, deceptive, and treacherous conduct.
The pangs of hunger cause soldiers to act more like ravenous beasts, than rational beings. It is animal instinct which impels the soldier to seek first for the gratification of his appetite. Some persons, instigated by carnivorous desires, yearn for raw meat, and will not be satisfied unless their food is flavored with the flesh of animals. Their bodies increase and thrive, even to repletion. Contrast these individuals with pale, lean, anæmic people, who crave innutritious articles of diet, and eat soft stones, slate, chalk, blue clay, and soft coal. Such perversions of the appetite are manifested only when there is either a diminution in the volume of blood, deficient alimentation, defective assimilation, or a general depravity of the nutritive functions. Morbid conditions generate vitiating tendencies and destroy the natural appetite.
While alcoholic stimulants affect the medulla oblongata principally, opium acts chiefly on the cerebrum, and excites reverie, dreamy ideality, optical delusions, and the creative powers of the imagination; some of these hallucinations are said to be grotesquely beautiful and enjoyable. The effects of this agent differ from those of alcoholic intoxication by not deadening the moral sensibilities, or arousing the animal propensities. Opium smokers are dreamy and abstracted, not quarrelsome or violent. Those who use ardent spirits lose their moral delicacy, their intellect becomes dull, the reason cloudy, and the judgment is overruled by appetite. It is conceded that thetrophic centeris principally in the medulla oblongata; the cerebellum and lower cerebral ganglia, however, favorably influence the nutritive functions, and, when these organs are large and active, a plethoric condition is the natural consequence. Redundancy of blood in the body indicates preponderance of the basilar organs. These facultiesbeing vehement in character, an excess of animal characteristics produces those conditions which result in acute and inflammatory diseases. We may express these conditions of the system as follows:
TheAnimal Facultiescorrespond to the lower instinctive manifestations.
These naturally give rise to the following diseases: Inflammation, Rheumatism, Gout, Convulsions, etc., which, in these conditions, pursue a violent course.
Although the middle lobe of the cerebrum, at the base of the brain, does not denote decided force of character, or energy of constitution, yet it has a certain sphere of normal action which is essential to the harmony of mind and body. If this region is largely developed, the constitution is languid, inefficient, sensitive, and abnormally disposed. But if it be deficient, the volitive energies preponderate, and there is a lack of those susceptibilities of constitution, which prevent excessive waste. The cerebral faculties are Fear, Anxiety, Sensibility, Servility, Relaxation, and Melancholy, and their excessive predominance indicates a weak, vacillating, irresolute character, and the existence of those bodily conditions which producegeneral excitabilityand chronic derangement. A full development of this portion of the brain indicates that the person is naturally dependent, inferior, and subservient to stronger characters. Such a one is fearful, fretful, complaining, irritable, dejected, morose,and, sooner or later, becomes a fit subject for chronic disease.[5]The ultimate result of excessive fear, excitability, and irritability, is functional or organic derangement,—the morbid conditions represented by the word Disease. The medulla oblongata and portions of the middle lobe of the brain, the functions of which represent Excitability, Anxiety, Fear, and Irritability (symbols of physical profligacy), are located just between the ears (see Fig. 60). Inferior animals distinguished for breadth between the ears are not only cunning and treacherous, but very excitable and irritable. The head of the Fox is remarkable for its extreme width at the region of Fear. He is proverbially crafty and treacherous, always excitable, and so variable in temper that he can never be trusted. He is a very timid thief, exceedingly suspicious, irregular in habits, and frequently driven by hunger into mischievous depredations.
Illustration: Fig. 75. Sly ReynardFig. 75. Sly Reynard
The organ of alimentiveness, located directly in front of the ear, indicates the functional conditions of the stomach, which, when aroused by excessive hunger, exerts a debasing influence upon this and all of the adjacent organs, and is demoralizing to both body and mind. In obedience to the instinct of hunger, children will slyly plunder gardens and orchards, displaying profligate, if not reckless tendencies in the gratification of the appetite. In this regional division we include the medulla, the posterior and middle portions of which give rise to the pneumogastric nerve. This nerve receives branches from the spinal accessory, facial, hypoglossal, and the anterior trunks of the first and second cervical, and its filaments are distributed to thelungs, stomach, liver, spleen, pancreas, and gall bladder (see Fig. 60, with explanation) Its agency is necessary to maintain the circulation, and the respiration, since, as the medium of communication, it conveys from the brain large supplies of nervous force to sustain these vital functions. It likewise instantly reports the impressions of these physiological processes to the brain, and especially to those parts which, by analogy of functions. It likewise instantly reports the impressions of these physiological processes of the brain, and especially to those parts which, by analogy of functions, are intimately related to the stomach. Hence, we observe that the conditions of the stomach give rise to reflex impulses, which involuntarily excite the animal faculties to the gratification of the appetite. That the stomach has an intimate connection with the rest of the organism is evident from the fact that when it is inflamed the body is completely prostrated.
We have already alluded to the perverting tendencies of alcoholic stimulants. Their peculiar influence upon the cerebellum causes the subject to reel and stagger, as though a portion of that organ were removed; the group of energetic faculties is stupefied, and mental as well as corporeal lethargy is the result. The reaction, which inevitably follows, is almost unbearable, and relief is sought by repeating and increasing the poisonous draughts, the primary influence of which is stimulating, the ulterior, depressing. Alcoholic stimulants unduly excite the nervous centers, the heart, and the arteries, and, consequently, the blood is carried to the surface of the body, where it counteracts the influence of cold and exposure, the frequent attendants upon drunkenness. The use of alcoholic beverages perverts the appetite, interrupts habits of industry and destroys all force of character. Pecuniary, physical, and mental ruin, therefore, are sure to follow as the consequences of habitual, alcoholic intoxication.
That ordinary alimentation, which includes the process of digestion, the subsequent vital changes involved in the conversion of food into blood, and its final transformation into tissue, causes mental languor and dullness, as well as bodily exhaustion, is attested by universal experience. A torpid condition of the liver, one of the most inveterate of chronic derangements, isindicated by sullenness, melancholy, despondency, loss of interest in the affairs of life, sluggishness, etc., and the ultimate tendency of this morbid state is towardssuicide. A broad and deep development of the middle lobe of the brain, shown by a fullness under the chin, and of the adjacent portion of the neck, denotes tendencies to somnambulism, delirium, and insanity. If such characteristics of the organization do not culminate in mental derangement, they exhibit childishness, helplessness, and great dependence. Age abates the vigor of the executive faculties, and old people manifest not only bodily infirmities, but the relaxing and enfeebling influences proceeding from the lower portions of the brain. They totter about in their second childhood, mentally and physically enervated. Those who become dissipated by the use of intoxicating beverages are not only weak, trifling, and foolish, but walk with an unsteadiness which betrays their condition. These illustrations show that this part of the brain is destitute of energy. Diseases of the digestive organs also indicate it. Cholera, whether induced by invisible animalcules in the air, or in water, takes the route of the alimentary canal, opens the vital gates, and myriads of victims are swept down to death. It proves remarkably fatal to those having this cerebral conformation. Perhaps enough has been said to indicate the relaxing and enfeebling tendencies of this region of the brain. They may be classified as follows:
This classification shows their tendencies to chronic disease, functional derangement, insanity, and suicide.
Before the structure of the brain was understood, Buffon spoke of it as a "mucous substance of no great importance." Its functional significance was so slightly appreciated that some people hardly suspected they had any brains, until anaccidentrevealed their existence. Latterly, however, it is generally understood that the perfection of an animal depends upon the number and the development of the organs controlled by the nervous system, the sovereign power of which is symbolized by a grand cerebrum, the throne of Reason. That animal which is so low in the scale of organization as to resemble a vegetable, belongs to an ascending series ending in man. The lowest species have no conscious perception, and their movements do not necessarily indicate sensation or volition. Instinct culminates in theArticulates, especially in Insects; while created intelligence reaches its acme in man, the highest representative of theVertebrates.
"All things by regular degrees arise—From mere existence unto life, from lifeTo intellectual power; and each degreeHas its peculiar necessary stamp,Cognizable in forms distinct and lines."—LAVATER.
"All things by regular degrees arise—From mere existence unto life, from lifeTo intellectual power; and each degreeHas its peculiar necessary stamp,Cognizable in forms distinct and lines."—LAVATER.