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others the same perception of the importance of his facts and opinions as he himself entertained. Perhaps it may have arisen from my attending more to his facts and opinions, than to his mode of explaining them, that I have been led to form so high an estimate of his intellectual powers. I can draw no other inferences from the facts than those which he has drawn, and therefore am I a convert to his opinions. p. 21.

This is a very elegant clog, no doubt; but it is not just the one we should have pronounced. Having no wish, however, to compete with Mr Abernethy in this species of composition, we shall content ourselves with remarking, that, while we look upon Mr Hunter to have been a singularly acute and faithful observer, both of the natural structure of the body, and its morbid changes, and to have promoted the science of surgery more by his treatise on Inflammation, than all the surgeons in Europe had done before him, by all their works put together, we scarcely know any physiologist, who, in his reasonings respecting the causes both of healthy and diseased phenomena, thinks and expresses himself, in general, with greater vagueness and inconsistency.

No part of his writings affords so many proofs of this, as his Treatise on the Blood. It is here that we find his speculations respecting the vital principle in general, and the life of the blood in particular; and really, although we have not confined ourselves to a single perusal of his reasonings on these subjects, we are not sure that we yet fully comprehend them. According to our present understanding of them, however, he seems to have maintained, that the principle of life was a matter diffused over the whole system ;-that it formed a constituent part of all the fluids as well as solids ;—that the brain and nerves were principally composed of it;-and that to it every part of the machine owed its peculiar properties, and its power of resisting decomposition. With respect to the source of this matter, he seems to have had no settled opinion; for we find him advancing two very different suppositions regarding it, almost in the same paragraph. One is, that the motion of the blood on the solids, generates it in the solids, and the motion of the solids on the blood, in the blood; the other, that the blood supplies it to alk parts of the machine, along with their nourishment.

The remarks we have already made, render it quite unnecessary, we trust, to reply formally to this modification of the doctrine of life. It is a conjecture-if conjecture it can be called -which has not a single argument in its support, and which explains nothing. And, indeed, were it not that the general tone in which it is advanced, clearly shows it to have been a favourite topic with its author, it is accompanied with one remark,

which we should have been disposed to interpret into a distrust of its soundness, even on his part. Life,' says he, is a property we do not understand: We can only see the necessary leading steps toward it.'

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In ascribing life to the fluids, as well as solids of the body, Mr Hunter seems in reality to have meant, that the supposition should apply only to the blood. The merit of this speculation, we believe, is entirely his own. To conceive,' says le, that blood is endowed with life, while circulating, is perhaps carrying the imagination as far as it will go; but the difficulty arises merely from its being fluid, the mind not being accustomed to the idea of a living fluid.' Nothing, we apprehend, can be truer than this; and we will only add, that the difficulty is one, which, we suspect, few imaginations will entirely succeed in overcoming. It is just as incorrect to say, that blood enjoys life, as it is to maintain, that malt possesses distillation: Blood is the material employed in the process,life, the process itself.

Nor is there, we believe, in all physiology, any example of an analogy more loose, or an induction more imperfect, than that which seems to have suggested this theory to the mind of Mr Hunter. Assuming, in the first place, that the contraction of a muscle is, of itself, a sufficient proof that it is possessed of life, he then maintains, that muscular contraction, and the coagulation of the blood, are analogous phenomena;—that is, that the decomposition of a fluid, by which it is separated into two parts, one a little thicker than the other, and by which its chemical constitution is for ever altered, is similar to the temporary shortening of an organized fibre, unaccompanied by the slightest perceptible change in its clementary composition. And in order to strengthen this analogy, he endeavours to show, by a variety of experiments, that the coagulation of the fluid, and the contraction of the fibre, are often promoted or retarded by the same chemical circumstances. The experiments, however, have no pretensions to accuracy in theinselves; and even if they had, they are altogether inconclusive. Phenomena, in reality very different from each other, may be modified in a similar manner by the same cause. It has never, we believe, been considered by physiologists as any argument for the similarity of sensation and voluntary motion, that both are effectually destroyed by a large dose of a narcotic. In the next place, with the view of lessening our natural tardiness to conceive that a simple fluid can be endowed with life, he brings forward experiments, by which he imagines it to be clearly established, that both the yolk and the white of the egg are examples of this

phenomenon. Here, however, as in the former instance, the experiments are faulty, and do not warrant the conclusions deduced from them.

Such are the doctrines, of which Mr Abernethy is bold enough to maintain the probability and rationality in the pamphlet before us. Of the nature of his defence, we shall allow our readers to judge, entirely from his own language; for, as Mr Abernethy, in becoming the champion of Mr Hunter, has borrowed a little of his armour of obscurity, it is more than probable that we should misrepresent, in endeavouring to interpret, his meaning. Besides, it is right that our readers should be presented with a few specimens of that eloquence, which is calculated to move the feelings of a Royal College of Surgeons.

Before proceeding, however, to any extracts, it is proper to observe, that Mr Abernethy has attributed opinions to Mr Hunter respecting the nature of the Vital Principle, directly the reverse, it seems to us, of those which that physiologist actually entertained. He is uniformly represented by Mr Abernethy as supposing that the principle of life is a subtile and invisible substance, of a very quickly and powerfully mobile nature;' whereas, Mr Hunter himself, without once affirming that he regarded it as either subtile, or invisible, or the contrary, distinctly states, in the only paragraph in which its circumstances with respect to motion or rest are considered, that it is a motionless matter.

The following passages comprehend the whole substance of Mr Abernethy's inquiry into the application of the hypothesis of the Vital Principle to the explanation of Irritability.

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I proceed to inquire,' says he, into Mr Hunter's opinion, that irritability is the effect of some subtile, mobile, invisible substance, superadded to the evident structure of muscles, or other forms of vegetable and animal matter, as magnetism is to iron, and as electricity is to various substances with which it may be connected. Mr Hunter doubtless thought, and I believe most persons do think, that in magnetic and electric motions, a subtile invisible substance, of a very quickly and powerfully mobile nature, puts in motion other bodies which are evident to the senses, and are of a nature more gross and inert. To be as convinced as I am of the probability of Mr Hunter's Theory as a (of the) cause of irritability, it is, I am aware, necessary to be as convinced as I am that electricity is what I have now supposed it to be, and that it pervades all nature. To obtain this conviction, it is necessary that the facts connected with this subject should be attentively considered; but for such an examination I have no time; neither would it be considered as suitable to the general design of these Lectures.' p. 39.

See his Treatise,' p. 89,

Taking it for granted that the opinions generally entertained concerning the cause of electrical motions are true, analogy would induce us to suppose, that similar motions might be produced by similar causes, in matter organized as it is found to be in the vegetable and animal systems.

The phenomena of electricity and of life correspond. Electricity may be attached to, or inhere, in a wire: It may be suddenly dissipated, or have its powers annulled; or it may be removed by degrees or in portions, and the wire may remain less and less strongly electrified, in proportion as it is abstracted. So life inheres in vegetables and animals; it may sometimes be suddenly dissipated, or have its powers abolished, though in general it is lost by degrees, without any apparent change taking place in the structure; and in either case putrefaction begins when life terminates.

'The motions of electricity are characterized by their celerity and force; so are the motions of irritability. The motions of electricity are vibratory; so likewise are those of irritability. When by long continued exertion the power of muscles is fatigued, or when it is feeble, their vibratory or tremulous motions are manifest to common observation; but the same kind of motion may be perceived at all times by attention, as has been shown by Dr Woolaston in the Croonian lecture for the year 1810. It is then I think manifest, that Mr Hunter's conjectures are the most probable of any that have been offered as to the cause of irritability. p. 41.

That the same doctrine is fully adequate to the explanation of all the functions of the nervous system, is shown with equal spirit, and still more admirable brevity, thus

Mr Hunter's opinion of a subtile and mobile substance, inhering in the nervous chords, is not essentially different from that of Haller. He does not indeed suppose it to be confined in tubes, neither does the philosophy of the present time require such a supposition; for no one at present will doubt that a subtile substance may be attached to, or inhere in a chord, without mechanical confinement. Will not a wire when electrified continue to be so, if surrounded by non-conductors? Experiments made on the limbs of animals with electricity, produced in the manner first explained by Volta, show that different parts of the body have different conducting powers; skin and membrane being very bad conductors-and brain, muscle and blood, being remarkably good ones.

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The celerity with which motions are transmitted from the tangible extremities of nerves most distant from the brain, and the celerity with which volition is transmitted to the muscles, in consequence of sensations thus induced, are sufficient to convince us that such effects must be produced by the motions of a very mobile substance. It is not necessary to suppose, that when such motions are transmitted along the nervous chords, an evident motion of the visible matter of those chords should be induced. Electrical motions take place along a wire, without occasioning any visible motion of the metal itself. p. 69.

In the first Lecture, I endeavoured to show, that Mr Hunter's theory of life was verifiable, and that it afforded the most rational solution of the cause of irritability, which had hitherto been offered to the public. It now appears that it does not essentially differ from that of the best physiologists with regard to the explanation it af fords of the nervous functions. p. 79.

Lastly, Mr Abernethy undertakes to prove, that the Hunterian hypothesis is sufficient to account for the prevention of putrefaction, and the regulation of temperature in living bodies; which he does in the following manner.

If the vital principle of Mr Hunter be not electricity, at least we have reason to believe it is of a similar nature, and has the power of regulating electrical operations. That electricity is the great chemist both in organized and unorganized bodies, will be generally credited; and that the power which combines may also prevent decomposition, is too obvious to need discussion. That electricity is capable of augmenting and diminishing the temperature of unorganized matter, is well known. Does not platina wire drop like wax in fusion, when it intervenes between the different ends of the Voltaic battery? and do not the spherules of rain fall to the ground at midsummer as firmly frozen as in the depth of winter, when they pass through a stratum of air refrigerated by electrical operations? I believe I need say no more on these subjects. p. 88.

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Thus,' concludes Mr Abernethy, my mind rests at peace in thinking on the subject of life as it has been taught by Mr Hunter. * P. 94.

Now, whatever our author may have intended this Inquiry' to be, we think it must be pretty apparent to every one, that it is any thing but a defence of Mr Hunter's theory. It is the development of a speculation altogether peculiar to himself: And if its object be not to maintain, that life is electricity, which Mr Abernethy, very inconsistently with his argument, disavows, it is, that since there is one subtile, invisible, and powerfully mobile, substance, in nature, there may be another;―a proposition, we should think, which few will be inclined to deny.

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The experiments of Sir Humphrey Davy,' says Mr Abernethy, seem to me to form an important link in the connexion of our knowledge of dead and living matter. He has solved the great and long hidden mystery of chemical attraction, by showing that it depends upon the electric properties which the atoms of different species of mat. ter possess: nay, by giving to an alkali electric properties which did not originally belong to it, he has been able to control the ordinary operations of nature, and to make potash pass through a strong acid, without any combination taking place. That electricity is something, I could never doubt; and therefore it follows as a consequence, in my opinion, that it must be every where connected with those atoms of matter which form the masses that are cognizable to our senses

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