to us very similar to those adopted by Linnæus to comprehend the whole Systema naturæ. Lapides crescunt, vegetabilia crescunt et vivunt, animalia crescunt, vivunt et septiunt.

We shall, perhaps, be accused of having dwelt too long on topics so unimportant.. For this we have already made our apology, and may now add, that such subjects are perpetually obtruded on the public, and the attention to them, we are convinced, proves a considerable retardation of progressive improvement in a most important science. For this reason, we have not hitherto attempted to defend ourselves from some animadversions in a most respectable journal, which we could not doubt were directed to us:-we are the more ready to do it now, as it may prove the means of introducing a subject the importance of which cannot be questioned, and to which we have devoted several pages in this and in our preceding Number. We can assure our candid and very respectable brethren, that, when we acknowledged our incapacity to understand Dr. Carson, we spoke only our real feelings; and, we regret to say, such is our dulness, that, notwithstanding all that has been written by way of elucidation, we still remain in the dark. We are glad to find, however, that, in the "cause of the blood's motion through the arteries, Dr. C. does not materially differ from other writers." If we understand the question, his discovery is in "the manner in which the blood enters the heart from the vena cava. To account for this, some hydrostatic laws are proposed, explaining the effect of the resilience of the lungs, the vacuum in the heart, and the law by which all fluids find their level. We are by no means certain that we are right in these positions; because it is well known that the blood circulates in animals that have no lungs and no heart,* consequently no resilience and no vacuum. Nay, we are assured that, in animals whose lungs are formed like the human, the circulation will continue ten or fifteen minutes after respiration has ceased. We are aware that some of the advocates for resilience claim it only

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* See Hunter on the Blood, p. 183, chapter on the Heart.

as

as an auxiliary power:* hence it may be urged, that the heart can do without it for a quarter of an hour or so. Without inquiring into so complicated a subject, we shall just copy, from the same writer, Dr. Carson's manner of explaining that process, which is now pretty generally called "the adhesive inflammation."

"When a wound is made in the body, and the parts brought together and kept in that state, the plastic nature of the blood that had oozed out of the arteries drying near the surface, unites the edges of the wound; but the blood oozing out of the arteries remains liquid. The veins in the mean time have become emptied, in consequence of the blood which they contained having taken the less resisted course, and returned to the heart. The blood, then, which had flowed from the mouths of the arteries into the interstices between the divided surfaces, being less resisted towards the mouths of the veins than in any other direction, necessarily enters the veins and continues its course to the heart. Other blood follows, and thus a communication is established between the artery and the opposite vein. The blood forming this slow current coagulates upon the external surface, and in due time a vessel is thus formed between an artery on one side and a vein on the other of the wound."

Now, is this intended as a riddle, or is it a description of the properties of the blood to coagulate, and, if it retains its life, to unite parts which were previously divided?—all which has been so minutely described by the most accurate physiologist of the last century.

We are now led to consider the experiments of a physiologist who has done much to improve the healing art, and whose pathological doctrines we have always treated with respect. By this gentleman's experiments, it appears that an artery has no pulsation, excepting when external pressure is applied to it. We are not disposed to do more than express our doubts whether the experiments hitherto made are

* A kind of "suction influence," another journal calls it, "which explains, and which only can explain, why a punctured vein does not bleed unless a ligature is thrown upon it, between the puncture and the heart." If this were established with certainty, how much trouble might be spared in bandaging an arm after bleeding! See Annals of Med. p. 167.

conclusive. We have been told that, in the artery of a dog, mere exposure is enough so far to alter its action as to induce a contraction almost equal to obliteration. This experiment has been confirmed by another writer. "It is singular," says he, "that, on exposing arteries, a contraction of a small portion, sometimes forming a mere ring, frequently took place, with a corresponding augmentation of the part just above." Now, this is exactly what we should expect if an artery, by exposure, is deprived of its vasa arteriarum, which, it is well known, are derived from the surrounding parts. In this condition, as we observed in our last Number (see pages 502 and 505), there is an imperfection in the ar tery, which (to use a language we find most writers are at last obliged to adopt) may induce the artery to act as if "from a consciousness of its own condition." Thus, without being aware of it, we fall into another mode of expressing Mr. Hunter's "stimulus of necessity;" that is, the new condition of the parts, and the danger to which the animal is exposed, proyes a stimulus to a new mode of action, and, under this new mode of action, the pulsation may cease.

We have offered this hint to show how many minute circumstances are often overlooked, even by accurate philosophers, in making experiments on living animals. A still more important consideration, however, is within our view. By the experiments which have been lately made on arteries, we have reason to believe that their contractile powers is much greater than is generally supposed. We are aware that this is not so well ascertained in the human subject, yet Mr. Warner succeeded in stopping the bleeding of divided arteries in the leg and fore-arm without ligatures.*

Thus

We recollect a tradition, that, in those days, government proposed experiments to be made on the larger arteries of condemned criminals. The surgeons very fairly felt themselves lessened by being made executioners, and demanded the liberty of taking up the arteries, if the agaric should prove unequal to stopping the flow of blood. This was refused, and the criminals were liberated. In these more enlightened days, might not some criminals who have

forfeited

Thus have we somehow brought ourselves to a real Retrospect; and, in so doing, we trust, have convinced our readers how completely retrospective we have always been. This subject will again occur in our critical department, in order that our readers not only may be enabled with greater facility to comprehend the whole, but led to compare and reason for themselves. We shall anticipate some of Mr. Bell's remarks on the ligatures of arteries, reserving our general analysis of his work till the whole volume is completed.

After several observations on some " ingenious trifles which have been offered as improvements," and "on what he was taught both in the dissecting room and the hospital, his early experience in preparing for his injections," &c. Mr. B. proceeds to a detail of "what is essential to the ligature on an artery." This is afterwards summed up in the following paragraph: "There are thus four changes, 1. The obstruction of the artery by the ligature. 2. The formation of a clot behind the ligature. 3. The discharge of coagulable lymph by the inflamed coats. 4. The final change by which these coats degenerate into a common texture." All these are exhibited in the plate, and the examples are taken from the human subject."-Now, if we understand Dr. Jones, great care must be taken that the artery is not permanently obstructed, if justice is done to his operation; and, if this is really the case, the clot of blood and the discharge of coagulable lymph appear to us both equally unnecessary, or are provided for without the necessity of obstructing the artery by ligature. Indeed, Mr. Bell gives an instance in which the carotid of a dog was obstructed by a cord put loosely round: an engraving shows the same vessel in an ass obstructed in a similar manner. "The ligature lies quite loose, was never drawn, consequently never cut the coats of the artery; an incised wound could, therefore, not have been

forfeited their lives by the severity of our laws be selected, to see how far an artery will contract by mere exposure, or what other means might be used to lessen the most painful and most dangerous part of many operations.

made

made here, nor could the blood be mechanically obstructed by the ligature, yet the artery is obstructed, the effect of the ligature is perfect." If such is the case, and we are not disposed to doubt it, where is the necessity for "obstructing the artery by a ligature;" or what proof have we that the coats are inflained in order to throw out coagulable lymph?

As Mr. Bell's performance will come before us again, we should dismiss it at present were it not for a remark or two on his language very much to our purpose. Where did he meet with the expression, "an artery's stimulus to its perfection," or what are his motives for adopting, with apparent reluctance, "what is called in the present language of surgery the adhesive inflammation?" If these expres

sions are used as the most appropriate, it would have been handsome to have given the inventor credit for them. But, in our opinion, one of them is improperly applied, and the other hastily assumed: Ist. As far as has hitherto been discovered, the artery contracts, as the blood coagulates, from the stimulus of necessity. The artery was previously as perfect as the nature of its functions required, but now it is unequal to those functions, and, in order to preserve the animal, contracts till it is gradually obliterated. 2ndly. There have hitherto been no proofs that the adhesive inflammation is at all necessary for the union of the sides of the artery; though Dr. Jones discovered an effusion of lymph when he cut through the inner coats of an artery; yet that process could not be the cause of its obliteration, as blood afterwards circulated through it, and it has even been found that contractions have taken place where no coagulated lymph was discovered.

Thus have we been insensibly led into the retrospect of surgery before medicine. We have but few other remarks

*The stimulus of perfection is a term used by Mr. Hunter to signify those actions by which an animal arrives at the highest degree of perfection of which his nature is capable. Of this kind are the descent of the testicle, and the various changes which occur at puberty, &c. An action is induced by the stimulus of necessity, when the animal's life is endangered, and only sayed by such an action.

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