In all these cases a new condition of the cerebral circulation is` established. The vast net-work of capillary blood-vessels in the excited organ becomes expanded by an increased supply of arterial blood. And while this is occurring, we know, with mathematical certainty, that other portions of the brain are diminished in circulation and impaired in function. Thus does education exert the power of essentially changing the form and condition of the brain. The over-excited organs not only expand in consequence of the increased supply of blood, but receive additional nourishment and growth, which gives them a paramount ascendancy over their diminished antagonists. The gradual absorption of the inactive organs, according to the general law of physiology, which applies to all parts of the body, completes the change in the structure of the brain.

The power of one portion of the brain, under local excitement, to suppress or restrain the functions of other portions, is highly important in reference to the mutual antagonism and co-operation of the cerebral organs. Neurology demonstrates, that every cerebral organ is balanced by an organ of the opposite function, so as to complete the symmetry of the human character, and give us an unlimited freedom of action in every direction. These opposite tendencies, the recognition of which is essential to a just conception of the human mind, are located in opposite regions of the brain; and as the exercise of any function or faculty naturally tends to over-rule or suspend its opposite, so do the organs of opposite faculties, by their position and mechanical relations in the brain, counteract each other and exercise a mutual restraint.

A large portion of the philosophy of man is, therefore, explicable by reference to the mechanical constitution of the brain, and the hydraulic laws of its circulation. In discussing the functions of particular organs, I propose to show how the application of the hydraulic laws explains the correlation and reciprocal influences of the organs. At present, as it would be premature to present all. the relations of particular organs, I would merely state the principal hydraulic laws of the brain, which are at the foundation of many highly important laws of the mind:

First Hydraulic Law. The excitement and expansion of any portion of the brain, tends to produce a proportional compression and restraint of the opposite portion.

This is an obvious consequence of the simplest principles of mechanics. If we press upon a soft viscus inclosed in a firm cavity, the pressure will necessarily be transmitted chiefly to the opposite point of its surface. If we press from above, the pressure will be principally felt upon the bottom; if from below, it will principally be felt upon the upper surface. The opposite region of the brain, which is thus compressed, is generally the special opposite or functional antagonist of the one by which it is compressed. Thus does the excitement of every organ increase its power, by suppressing, at the same time, all influence that would tend to counteract it.

Second Hydraulic Law.-The organs immediately adjacent to the one which is subject to any strong excitement, are also liable to compression. Hence, the strong excitement of any faculty or passion not only antagonizes the passion or faculty of an opposite character, but equally checks the development of those which are most similar.

The application of these two hydrostatic laws, in the consideration of special organs, furnishes a beautiful and interesting illustration of the connection between mental phenomena and our physical

constitution.

The concentration of excitement in any part of the brain may arise from various causes. The most usual cause is the presentation of the appropriate object to the organ, as when Combativeness is roused by an injury, or Fear by an impending danger. When the cerebral circulation becomes morbidly irregular, so as to manifest violent excitement, independent of all external influences or motives, we regard the mental condition as unsound or insane. When, on the other hand, it is impossible to produce too high or predominant an excitement of a particular passion, we ascribe this condition to a predominance of Firmness and Health over the sensibility and excitability of the constitution. When the nervous system is highly predominant, and its sensibilities have attained the highest degree of acuteness, we are not only powerfully affected by every motive suggested to our minds, but the brain is susceptible of being influenced by the most subtile causes. In other words, the temperament is highly impressible, and the application of the hand to the head will exert a sufficient influence to excite the subjacent organs into predominant activity. In this case it is probable that the cerebral circulation changes in accordance with the character of the excitement. The circulation may change with instantaneous quickness, and the most sudden revulsions in feeling, might be referred to changes in the circulation, through the immense ramifications of blood-vessels which occupy the superficial portion of the brain.

Changes in the mental condition are due, not only to a change in the rapidity or direction of the circulation, but to a change in the character or composition of the blood itself. When the blood is largely supplied with red globules, which give it the bright-red, arterial color, the action of all the organs is more prompt, vivid and vigorous. When these elements are defective, and the blood is of a pale, watery constitution, the mental as well as the physical or gans operate more feebly. When any of the elements of the blood are absent, or developed to an undue extent, the action of the brain is in some degree modified, and the character, spirits and intellectual power, sensibly changed. Thus, when the blood possesses an excessive amount of the element called fibrin, which causes its coagulation, and which is similar in constitution to the muscular system, the influence of such blood stimulates the basilar, rather than the coronal and intellectual organs. On the other hand, when the

blood is defective in fibrin, so as to coagulate very feebly, it fails to stimulate the animal organs of the brain, and there is a deficiency of energy both in the mental and bodily constitution. When the blood becomes surcharged with carbon and carbonic acid, in consequence of indolent habits and imperfect action of the lungs and skin, the capillary circulation becomes more languid, and the whole action of the brain is enfeebled. When the hydro-carbonaceous elements of the bile, which should be secreted by the liver, are retained in the blood, they exert a prejudicial influence upon all the superior anterior regions of the brain, diminishing the intellectual and moral force, while they excite certain basilar organs which produce an irritable and melancholy temper. When the action of the kidneys is impaired so as to suspend their usual secretion of urea, this urea being retained in the blood, exerts a narcotic influence upon the whole brain, and finally reduces the patient to an insensible or comatose condition. So when the deranged action of the kidneys discharges a considerable amount of the albuminous elements of the blood, instead of their legitimate secretion, we find the brain injured by this change in its blood, and epileptic convulsions have frequently been observed as the consequence.

Thus every change in the composition of the blood produces corresponding changes in the action of the cerebral organs. Indeed, I have no doubt that, if vital chemistry were sufficiently advanced, it would be practicable to determine, from the composition of the blood, the condition of the organs of the brain.

Every cerebral organ, we may infer from several reasons, tends to produce a definite constitution of the blood; and it is certain that each organ tends to produce a certain condition of the cerebral circulation, some favorable and others unfavorable to a sound and healthy action of the brain. The basilar organs of the passions excite the muscular system, and produce a violent and irregular circulation in the brain, quite unfavorable to the action of the mental and moral powers. It is to be observed, that those organs which are most favorable to the ascendancy of the mind and the harmonious action of the brain, lie in the upper-half; while those which exert the most deranging influence, lie in the basilar region. There are many reasons for this arrangement, not necessary now to mention; but it is an obvious suggestion, that the organs in the basilar portion of the brain lie in contact with the large blood-vessels by which the blood enters the brain and is returned to the body. Hence, the action and expansion of these organs may easily derange the cerebral circulation, by compressing the arteries through which the blood enters the brain, or the veins through which it takes its departure. In the one instance, rendering the cerebral circulation slow-in the other, oppressing the brain by venous congestion; or, in case one class of vessels should be compressed while another class is relieved from compression, extraordinary inequalities in the circulation of the brain must be produced.

Thus do the organs in the basilar portion of the brain, in conse

quence of its mechanical arrangements, exert a remarkable modifying and deranging power over the circulation; while the organs of the higher emotions, not being so situated as to interfere with the arterial influx or venous efflux of the brain, exert no such deranging influence, but preserve the mind in a calm and equable serenity. Many of the phenomena of apoplexy, epilepsy, syncope, dreaming, trance, hysteria, &c., may be explained by reference to the position of the organs, and their mechanical influence upon the blood-vessels. Not only do the minute capillary blood-vessels change their condition under the influence of organic excitement and pressure, but the larger vessels, as the longitudinal and lateral sinuses, the carotid and vertebral arteries, and all their ramifications, hold the most interesting relations to the adjacent parts of the brain, by which they may be affected. It would be a work of great nicety and interest to trace the manner in which the cerebral organs propagate their influence mechanically through the brain, showing how any organ is thus enabled materially to assist or impede the functions of others, by modifying their circulation of blood. This reciprocal influence is exercised partly mechanically, and partly physiologically. Each hemisphere of the brain exerts a physiological control over the opposite half of the body, and consequently over the opposite cerebral hemisphere, by means of which control it may determine the whole course of the circulation and nervous energy. Thns, whatever organ may be excited, the whole cerebral circulation is soon brought into accordance with its character, and all organs calculated to restrain its predominance are restricted in their circulation as much as those of a congenial character are assisted; while the remainder are modified in a peculiar manner, which can be understood only after we have studied the mathematical laws that govern these hydraulic phenomena.

The rigorous manner in which the changes of the cerebral circulation are controlled by the solid cranium is, perhaps, liable to a slight exception, arising from the facility of secretion and absorption. If the solid contents of the cranium do not undergo any change, it is obviously impossible to change the amount of the fluids. The solids are liable to slight and very gradual changes from the growth of active, or absorption of inactive, organs-but the fluids are liable to much greater and more sudden changes. The brain and spinal cord are regularly supplied with a limpid cerebrospinal fluid, usually to the amount of two or three ounces, but sometimes even four or five times that amount, when, from old age or other causes, the cerebral substance is absorbed. This fluid is located around the convolutions, between the exterior membranes (dura mater and arachnoid) and the immediate investing membrane of the convolutions, the pia mater, and also in the interior of the ventricles. As this limpid secretion may be readily evolved or absorbed by the blood-vessels of the head, the changes which take place in its quantity give greater room for the blood when it is absorbed, and diminish the supply of blood when the serum is secreted in excess.

ART. II-MESMERISM IN INDIA.

BY JAMES ESDAILE, M. D.

CHAPTER II.-(CONTINUED.)

ACCIDENT alone determined my choice, and decided the matter for me, perhaps much better than theory would have done; for I should as soon have thought of commencing operations on the first dog or pig I met on the road, as of selecting this man for his good mesineric "materiel."

There are some interesting particulars in this first successful mesmeric experiment in India, to which I beg leave to direct the reader's attention.

I. The purely accidental and unpremeditated nature of the experiment.

II. All want of consent between the parties.

III. The operator's want of belief in his own power; for I had never seen Mesmerism, and all I knew about it was from scraps in the newspapers.

IV. The absolute ignorance of the patient; it being impossible that he should ever have heard of Mesmerism.

V. The impossibility, therefore, of imitating the mesmeric phe

nomena.

Under all the circumstances of the case, collusion between the parties, will not, I presume, be suspected; and every possible care was taken to exclude any source of fallacy in the experiment. European gentlemen, skeptical and critical, or so strong in disbelief that they would have reasoned themselves out of their senses, if they could: ignorant Hindoos and Mussulmen, who merely used their eyes and ears without an attempt at reflection, will all be found, by their separate and independent reports, bearing testimony to the same series of phenomena. As I might never succeed again, I endeavored to make this case as perfect as possible in all its parts, by bringing the senses of different people to bear upon it, in all its stages; and, I must say, that I cannot see any possible opening for mistake or deception. It has for many months been before the Indian public, who were invited to point out any source of error that may have escaped me, and no attempt has been made to disprove the facts, or explain them away, except by the easy and sweeping charge of imposition in the patient, and delusion in the observers of the probability of which I shall now give the reader the means of judging.

FIRST EXPERIMENT.

Madhab Kaura, a hog-dealer, condemned to seven years imprisonment, with labor on the roads, in irons, for wounding a man so