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clusion, which is not supported by the testimony of direct fact and experience, we cannot pronounce that the influence of a nervous centre is necessary to any of the processes of organic life. We liave proofs that these processes are liable to be modified by certain conditions and affections of the brain; but, that the dependance is in the relation of a source with a channel of distribution, we have no absolute proofs; our testimonies amount only to this evidence, that these are the effects (viz, those which have been noted from a sensible demonstration) of a division of nerves. Such

appears

to be the condition of the evidence which relates to the connexion between remote organic life and the central termination of nerves.*

Though we find a great many good things in this chapter, yet we cannot help thinking the author has unnecessarily involved himself in mechanical and chemical causes, especially when he ascribes inflammation to any other cause than the actions of life. Perhaps we shall be told, that all the “chemico-hydraulic agencies” of which he speaks, are “ directed by the principle of life, to which a preternatural condition is superadded." This means, if we understand him, that they arise from the actions of life changed according to the nature and properties of certain stimuli; and that all such changes, or such preternatural conditions, being differ ent from the original or healthy actions, constitute disease. All this is extremely intelligible, and we heartily wish he had stopped here, by which he might readily have explained some difficulties, which, as they are insulated in notes, we shall transcribe. The first is as follows:

“ I am inclined to think, that there is a property of preserving for a certain time the fluidity of the blood, belonging to the vascular system, independent of motion; and that this property is one dependent upon

the nerves. The first part of the position is, in a great measure, confirmed by the formation of a clot in the sheath of a divided artery, which would no more take place in the sheath than in the vessel itself, if the fluidity of the blood were wholly dependent upon its motion; for this motion continues while the coagulation is taking place. The coagulation of the blood is, in this instance, aca counted for, by supposing that it becomes entangled, &c.; which is a very entangled sort of a supposition, because it flows in a space, and through this same space it may continue to flow, if its fluidity were maintained by its motion. This proof is not perfect, because the fact is not unquestionable; at least, the assigned order of its occurrence is not unquestionable. With regard to the second part of the position, the reasons which affect it are mentioned elsewhere."

* This expression, the central termination of nerves,' is frequently employed; and I adopt it, after Reil, because the denomination appears to me good for the purposes of distinction.” ST 2

The The second note.

“ I have remarked it only in tiro cases of inflammation; one of then has been already mentioned, the other was as follows: A woman, when rubbing a deal table, forced a splinter of wood half ant inch in length under the nail of tlie second finger; it produced intolerable pain and rapid swelling: about three-quarters of an hour af. ter the accident, I extracted the splinter, and, upon examination, found the arteries which supplied this finger beating 104 strokes in a minute, while the radial artery was beating only 92."

The third.

“ It is not the mere cessation of life which produces a slough. I believe that under some circumstances of the identity of this influence which is exerted by the nerves, a kind of inverse operation takes place upon the subjects of its former alliance, and that the slough so produced is essentially different from that putrefaction which succeeds to ordinary death; that it is, in short, state of the sensible textures, which no other agent in the universe could produce, save that principle of life, and which the principle itself can produce only under one condition of it. After ordinary death, the integrity of the textures may be a long time preserved; a slough may be formed in a few hours after the influence of a cause whose relation is with the principle of life,” · What connexion have these properties with hydraulics or chemistry? They are all of them the properties of life, which cannot be imitated by the application of any other laws. This is well enough illustrated in a passage in the text, which we shall transcribe, in order to relieve, as far as we can, this intelligent author from a difficulty we did not expect would be started in such a quarter.

“ The same principle (says he) not only regulates the calibre, but the cohesion also, of vessels: in acute inflammation, that property of the principle which prevents rupture of the arteries is generally increased, as the vessels in this state bear a great degree of distention: we have, however, an analogy for this in the arteries of the penis; we may therefore presume that the natural strength of the property is not diminished in inflammation. In the local determination of blood to which apoplexy succeeds, the force of this property must be diminished; because I have seen a man, who had two attacks of apoplexy, sustain phrevitis without such effect. This distinction, which has been deduced from my own experience, is very similar to one of Mr. Hunter, who supposed that in phlegmonous inflammation there is an increase both of the action and of the power of the vessels; while in iuflammation which terminates in mortification there is an increase of action, but not a corresponding increase of power :* by this word power' (than wbich no expres

“ * Treatise on the Blood, p. 8."

sion can be more vague), I understand the property of the organic spirit, by which the cohesion of the fibres of vessels is preserved."

We need hardly remark, that every action must be sustained by a corresponding power ; and the only power we know of in the living body is the power supplied by life. That this is greater at one time than at another, every man knows by his own experience. It is not less certain that, under particular circumstances, actions are accomplished to which the whole body, or certain parts, is unequal at other times. On such occasions, therefore, the power must be increased. From the nature of a living organ, this increase of power can only be supported to a certain degree; and, if action still continues, it must now suddenly cease.

Thug we find, that, after violent bodily exertions, the muscles suddenly cease to act; and, if that cessation extends to the heart, syncope sometimes follows, from which the subject does not always recover, or recovers very slowly. If this increased action is confined to a part, the powers of that part are increased; but, if the action continues beyond what the powers of that part can support, death must follow. But this death, being only partial, is effected by a new ac. tion, in which all the lymph in the vessels, having first disengaged itself from the serum and red particles, coagulates : the parts themselves are also immerged in the same substance, which instantly coagulates. Thus the parts not only die, but, in the last act of life, probably more powerful than any that preceded it, form themselves into a slough. By this mode of death, the vessels are secured from hæmorrhage, which would otherwise follow the separation of the dead part. Now, all these actions, even to the mode of dying and the separation of the dead part, are the effect of the living power, and cannot be imitated, though they may be induced by artificial means. That the nerves have a share in all these actions, we cannot doubt; but then we suspect that they have no other share than as chorde internunciæ. If this continuity of sensation is prevented, all sympathy ceases; and many of the actions which are necessary for the nourishment and restoration of parts cease with it.

Å section on the Diseases of Nerves follows. The first of these, as we might suppose, is the Tic doloureux. This chapter, which occupies 40 pages, is extremely well constructed. The experiments are well designed; the result of each related with equal minuteness and candour; and the inference from the whole such as impresses us with a high sense of the author's accuracy and fidelity, and with a proportionate estimation of his labours. If, as we suspect, Mr. Hunter some. where remarks, that divided nerves unite not by a growth

from

1

from the divided ends, but by a conversion of coagulated lymph into nerve, we shall not be surprised if Mr. Pring found all his endeavours at preventing a re-union, and consequent return of the disease, ineffectual. We will venture to suggest one other, which can only be accomplished where the nerve is not very deeply seated. We mean to remove the whole of the substance to below the part of the nerve taken away. Perhaps it may be as well to preserve skin enough to procure the healing by the first intent, or at least that may be tried, and, if not eifectual, the incised wound may be left to granulate and cicatrize in the ordinary way. A short practical paper on “ Tumours of Nerves' closes this section.

The third section," on the Effects of external Injuries of the Nerves," closes the volume, and is by far the most va. luable part to every practical purpose. The previous matter is, indeed, as we might expect, chiefly introductory to these most important conclusions. The first chapter, on Inflammation of Nerves, contains more well-directed experi. ments, fair inductions from them and from the histories selected from other quarters, than we have met with in any other work. Not that the experiments are unnecessarily multiplied; but, from the clear conception of the author, they are all directed to the object in view, and the inference from each is undeniable. If the general result furnishes less information than we flattered ourselves with receiving, we are bound to impute this to that judgment and sense of rec, titude which is perceptible in every part of the work. We every-where find experiments constructed, not to confirm a doctrine, though, doubtless, that must often have been the author's wish, but to inquire into the validity of his own or of other people's conclusions.

The last article is on Injuries of Nerves producing Spasms. In this the author has tetanus, or trismus, principally in view. The subject commences with a long quotation from a paper of Sir Everard Home's, which is quoted more at length than was necessary, principally lest any suspicion of misrepresentation should be attached to the relation. The case is certainly interesting, and does credit to the writer. The injury first received was by pressure on the thumb. The part healed, and for two years after no inconvenience was felt, excepting that the thumb was not always under the voluntary direction of the patient. During the third year, when in a post-chaise,

“A cold wind blew directly into the carriage, and he endeavoured to pull up the window; but, not seeing the glass, rise, he looked down, and his hand, instead of pulling up the window, was lying

"pon

upon his knee. The thumb was bent in towards the palm of the hand: a spasm came upon the muscles of the arm, making theme bend the elbow, and immediately he became insensible: in a quarter of an hour he perfectly recovered himself. Some hours after, upon bending his thumb, to shew what had happened to him in the car. riage, tbere was a return of the same attack, which also rendered him insensible for a few minutes."

No ill symptoms returned till more than two months after, when, eagerly waving his hand, a contraction seized the patient, and he suddenly fell to the ground in a state of in.. sensibility. From this time, these events occurred frequently, without any apparently exciting cause: the spasms were, however, in a certain degree, arrested by a tight ligature; and, as they were generally preceded by universal uneasiness, a tourniquet was always ready to be tightened on the first alarm. Electricity was found useless.

From the effect of pressure, and its interruption of the continuity of action, it was presumed that a division of the nerve might produce a more powerful effect. This was accomplished where the fibre passes under the annular ligament of the wrist to the thumb. The retraction of the cut-ends of the nerve was much greater than expected, as the nerve had been previously detached from all its surrounding connexions. A temporary universal spasm succeeded this division ; but, for eight hours afterwards, no spasm occurred. In fifteen hours the spasm was general, excepting that the brain was not affected. The wound not healing by the first intent, the callosity of the cicatrix became a source of uneasiness, and the spasms continued with little alteration, They were somewhat abated, as that hardness was absorbed; but returned in such a manner as to prove the inefficacy of the operation, which Sir Everard imputes to the wound not healing by the first intention.

From this time (continues Sir Everard) the patient was not under

my directiou; but I understood that he tried the effect of large doses of opium, which did not afford relief. He was then in. duced to employ electricity, which was also unsuccessful; and he died in a fit, which at the time was believed to be apoplexy, abont tive months after the operation had been performed; but, as the body was not examined, the nature of the fit could not be ascertained,

“ In this case, some of the branches of the median nerve had acquired from disease an unnatural power of contraction, which was made evident by the operation; and there is every reasou to believe that the spasmodic attacks which took place were in reality convulsive motions in the nerves theinselves, which excited corre. sponding contractions in those muscles which were under their influence."

Mr.

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