supply, but are reflected in loops; and that the filaments of which a nerve is composed, though bound together in the same sheath, yet pass separately into the spinal cord, and, according to some physiologists, (Valentin,) on to the brain, forming loopings also in the cerebral hemispheres, coming in contact in their passage along the cord with its grey matter; and this view appears to be corroborated by the phenomena of disease." "In proportion as nervous filaments pass through a greater quantity of grey matter, are their sensitive as well as reflex influences open to observation." There are some of his conclusions which we do not so readily follow, and which, in so far as we keep pace with him, fail to meet with our entire concurrence. The foregoing will present a concise, but tolerably faithful, analysis of Mr. Lee's general views of a very important and highly interesting subject.

After quoting Professor Cruveilhier, MM. Foville, Pinel, Grandchamp, Flourens, Cabanis, and others, in confirmation of his views. of the dependence of the spinal cord on the brain, he adds, that "the same objections that have been made with reference to reflex action as depending solely on the cord, apply also to muscular tonicity." Finally, he concludes his interesting and suggestive essay by submitting to the reader the following deductions:

I. That in man, and the higher mammalia, the brain is the sole centre of the nervous system, and the source of power.

II. That the grey matter of the spinal cord, and the ganglia of the sympathetic, are to be regarded as reservoirs of this power for the immediate actions of the parts supplied, which speedily become exhausted if communication with the brain be cut off; and also as modifiers of impressions transmitted from the periphery to the brain.

III. That the automatic and instinctive actions are not performed independently of the concurrence of the brain, though its influence is less direct and manifest than in the case of voluntary movements.

IV. That the brain is the organ principally implicated in several disorders, which have been too extensively referred to the spinal cord.

Original Communications, Translations, and Medical
Jurisprudence of Insanity.

ON THE CONNEXION BETWEEN PHYSIOLOGY, PSYCHOLOGY, NATURAL THEOLOGY, AND OTHER SCIENCES.

BY GEORGE OGILIRE, M.D.

Lecturer on the Institutes of Medicine in the University and King's
College, Aberdeen.*

Ir is proposed, in the present discourse, to point out the relation in which physiology, considered as a philosophical pursuit, stands to some other branches of science; and, in particular, it is intended to show that it stands related, in one respect, to the physical, and in another, to the metaphysical sciences, occupying, as it were, a station intermediate between them.

Physical science is concerned with matter, as influenced by various forces such as gravitation, chemical affinity, heat, electricity, &c.— whose tendency is to bring it into a state of motion, sensible or malicular. When, however, we speak of matter as influenced by certain forces, we must be understood as merely using a conventional form of expression; for we have no reason to suppose the influencing force to be distinct from the induced state of change; thus, sound, which may be spoken of as a force, is nothing else than a peculiar vibratory condition of the molecules of the sounding medium, and the same remark probably applies to heat, light, electricity, &c. Nor can we attach a different meaning to the expression when we speak of the body, or any part of it, as being under the influence of the vital force. All that is implied is, that the body is in a peculiar state of change, differing from matter not vitalized, much as a sounding body does from one that is mute. We may consider, therefore, vitality as a force co-ordinate with any of the above-mentioned physical forces, as, for instance, heat, or electricity -in other words, that a vitalized differs from an inanimate body, much as a heated does from a cold one, or an electrified from a nonelectrified one. And among these forces, the relation of vitality is closer to electricity than to any other one, though it is now generally admitted that they are only analogous, not identical. Just as a piece of iron placed in a certain relation to the electrical current, without altering either its physical or its chemical constitution, becomes a magnet, and acquires new properties different from those

* Read before the Medico-Chirurgical Society, Aberdeen, March 1st, 1849.

of other pieces not so situated, so certain organic compounds, when placed within the influence of the living tissues, become assimilated to them, and endued with life; acquiring new properties, and a capability of assuming new forms very different from what they previously possessed, having undergone, at the same time, it may be, scarce any appreciable alteration, either in chemical or physical characters. Thus the plasma liquor sanguinis appears nearly undistinguishable in either of these respects from some forms of fluid albumen, from which (as they are capable of being used for food) it may have been formed. Yet it has acquired new properties; for while the albumen tends only to resolve itself by putrefaction into its component elements, the fluid fibrine of the blood, immediately on being effused from the vessels, becomes solid, often assuming a distinctly fibrous structure; and the coagulum or solid so formed, if remaining in relation with the living tissues, will develop nuclei and cells, to be afterwards converted into a substance identical in properties and appearance with some of the natural and original tissues of the body. But not only is there thus a general analogy of action between the vital and electrical forces, but the action of the one may even excite that of the other. Thus electricity will not only excite contraction of the muscular fibre if applied directly to its substance as many other irritants will do, but also, if made to act upon the motor nerve supplying it, or even upon the nervous centre from which the nerve is derived; and the natural actions of many parts of the body may be excited by means of electricity, when the influence on them of the nervous system has been in various ways obstructed. Then, again, we find that it is by means of the nervous system that the action of the electrical organs found in certain fishes is subjected to the will of the animal. The act of volition causes a certain change in the nervous centre appropriated to this function, and the resulting influence, or nervous force, being transmitted along the nerve which supplies the apparatus, causes there a manifestation of electrical action.

The student of physical philosophy will not fail here to remark, that the researches of Faraday, and others, have shown that a similar reciprocity of action prevails among the purely physical forces. Thus heat induces electrical disturbance in the tourmaline, and in certain metallic combinations, and light induces magnetism, while the electromagnetic current will, under certain circumstances cause the deflection of a ray of light.

But we ground the relationship of physiology and physical philosophy, not only on the vitalized condition of the organism being

a state closely analogous to those conditions of inanimate matter which are treated of by the latter science, but also on the essential identity, both in chemical and in mechanical properties, between the living tissues and inanimate matter. So much is this the case, that many of the processes going on within the living body are entirely explicable by the laws known to regulate such changes in inorganic matter-e. g., the association of movements, the propulsion of the blood, and of the contents of the alimentary canal, &c., some parts of the processes of digestion and arterialization; though, at the same time, as already intimated, there are others to be referred apparently to a force (that of vitality) different from, though bearing an analogy to, those concerned in the production of simply physical phenomena, (e. g., the influence of the nervous system in causing contraction of the muscular fibre, as well as assimilation, nutrition, secretion, reproduction, &c.)

And there are other functions, again, of a complex nature, intermediate, as it were, between the two classes just noticed; it must, however, be admitted that the tendency of modern investigation is to extend the operation of physical at the expense of the purely vital phenomena.

I proceed next to speak of the relation in which physiology and pathology stand to the metaphysical group of sciences.

Under this group I comprehend psychology, or the philosophy of the human mind, and theology, or that of the Divine Mind; as also ethics, or that science which treats of the relations in which we stand to that Divine Mind and to each other. Now, as physiology and pathology are related to physics and chemistry, inasmuch as the living body about which they concern themselves is merely a form of matter subject in general to the same physical and chemical laws as matter not vitalized, as they are related to the philosophy of electricity and the cognate sciences; inasmuch as the matter of which the living body is composed has its constitution so influenced by its vitality as that it has properties differing from those of other and inanimate matter, much in the same way as a magnet has properties differing from those of other pieces of iron not magnetized; so in the case of our own species are they related to those of the present group, inasmuch as man's material body is influenced, not only by the force of vitality, but also by his immaterial mind.

I proceed, of course, upon the understanding that the nature of man is admitted to be twofold-that his body is the residence and instrument of an immaterial soul, which acts upon, and is acted upon, by the former through the intervention of the nervous system.

Such is the view, indeed, taken by almost all who have written on the subject of human nature. Not that I mean to say there is perfect unanimity on the subject, for there is a certain class of minds that delight in holding opinions opposed to those of the rest of mankind, solely, as it would seem in many cases, from the love of singularity. Thus we find some of the disciples of Bishop Berkeley denying the existence of matter, and calling in question the evidences of our senses, because they do on some rare occasions deceive us, and because we cannot have any demonstrative proof of the credibility of their testimony. And, in like manner, some authors deny the existence of mind as distinct from matter, holding that the mental phenomena exhibited by the higher animals are merely the neces sary result of certain molecular changes going on in their brainsin other words, not that the brain is the instrument of the mind, but that mind is a function of the brain, just as contractility is a function of muscle.

A little consideration, however, will show that our belief in the existence of mind and of matter rest essentially on the same foundation. We believe in the existence of our own bodies, (independently of the evidence of our external senses,) from an intuitive conviction in the truth of the impressions derived from our internal sensations. We believe in the existence of bodies, external to us, from an intuitive conviction of the trustworthiness of the evidence of our senses; and, in like manner, we believe in the existence of our own minds, as distinct from our bodies, from an intuitive conviction that we possess the power of thinking, willing, feeling, and remembering, and from a further conviction that these are powers altogether different in kind from those residing in any form of matter, which convictions we denominate consciousness; and we believe in the being of other spiritual existences, as much external to our own minds as the objects of sense are external to our own bodies, (and, in particular, of one Supreme Being,) originally, I conceive, from an undefined but irresistible conviction of their existence spontaneously arising in the mind. That such an intuitive conviction does exist in our minds is shown in various ways. "Most people are conscious of it in themselves, especially in the silence and darkness of night, or in other similar situations, when from the withdrawal of the more palpable impressions made on the mind through the external senses, it is more free to be affected by its internal convictions." This is particularly seen in the case of children. Why is it that a child

Williams' Study of Gospels.