FREQUENTLY as external hæmorrhages have, from the earliest periods of time, excited the attention and demanded the aid of medicine, it may em extraordinary that the most eminent of the profession should yet differ in the explanations which they have given of the process by which the constitution tends to suppress them. Such, however, is the fact. Some surgeons have viewed the subject too partially; one assigning this part of the process, and another that, as the cause of the whole phenomena: some have confounded the natural process with the circumstances induced by art; and others appear to have entertained opinions which were altogether erroneous. While these imperfections and contradictions stand on record, on a subject of such importance, some well-conducted experiments, by which truth may be sifted from the false and hypothetical, must be considered as great desiderata; and a successful attempt to supply those desiderata is entitled to the thanks of the pathologist.

Before entering on the immediate object of his work, Dr. Jones has given a few preliminary observations relative to the structure of the arteries, by which he chiefly attempts to shew, that the inner and middle coats of these vessels are easily torn by a slight force applied in the circumference, but that the outer coat is extremely dense, strong and elastic: so that "if an artery be surrounded by a tight ligature, its middle and internal coats will be as completely divided by it as they can be by a knife, whilst the external coat remains entire." He also observes that the truncated extremities of a divided artery retract a certain way within the sheath, and likewise contract in a greater or less degree. These facts are subsequently ap plied to the explanation of the process under examination.

He commences the work by a consideration of the doctrines proposed by Petit, Morand, Kirkland, J. Bell, &c. relative to the natural process of suppression, when the hemorrhage is from a divided artery; and then proceeds to relate his own expetiments, executed chiefly on horses and

2

dogs; in all of which the state of the vessels was ascertained by dissection a short period after death. Our limits will only admit of a brief account of the deductions which the author made for the experiments, on which his inferences are founded, we must refer the reader to the work, itself. The author shall speak in his own

words.

"The results of the experiments related in the last section" (amounting to nineteen in number), "will not allow us to give so concise and simple an account of the process as has hitherto been done; but they afford us one more satisfactory, because it accords better with the operations of the animal economy, in which we are accustomed to observe the most important changes gradually produced by the co-operation of several means ratherthan by the sole influence of any one in particular.. They accordingly shew, that the blood, the action, and even the structure of arteries, their sheath, and the cellular substance connecting them with it; in short, that all the parts concerned in or affected by hæmorrhage, contribute to arrest its fatal progress, by operating, in the case of a divided artery of mo derate size, in the following manner.

66

"An impetuous flow of blood, a sudden. and forcible retraction of the artery within its sheath, and a slight contraction of its extremity, are the immediate and almost simulta-" neous effects of its division. The natural impulse, however, with which the blood is driven on, in some measure counteracts the. retraction, and resists the contraction of the artery. The blood is effused into the cellular and passing through that canal of the sheath substance between the artery and its sheath, which had been formed by the retraction of the artery, flows freely externally, or is extravasated into the surrounding cellular membrane, in proportion to the open or confined state of the external wound. These fibres entangle the blood as its flows, and thus the gulum at the mouth of the artery, and which appears to be completed by the blood, as it passes through this canal of the sheath, gradually adhering and coagulating around its internal surface, till it completely fills it up from the circumference to the centre."

foundation is laid for the formation of a coa

"A coagulum then, formed at the mouth of the artery, and within its sheath, and which I have distinguished in the speriments by the name of the external coagulum, presents

inflammation." This fact was first noticed by Desault, and the experiments of Dr. Jones place the matter beyond all doubt. If a ligature is tied tight round an artery, and immediately removed, a large quantity of coagulating lymph is poured out from the division of the internal and middle coats, and the artery soon becomes completely impervious. We shall transcribe the first experiment.

"Aug. 6, 1803. A considerable portion of the right carotid artery of a dog was laid bare, and three ligatures were applied around it, close to each other, so as to cover nearly a quarter of an inch of the artery. The ligatures were drawn tight enough to cut through the internal and middle coats of the artery, and then, by means of a piece of small twine, which had been laid along the artery, and on which the knots of the ligatures had been made, were carefully removed, so as not at all to injure the artery. Dr. Farre, who assisted me in this experiment, and myself then observed the artery, until we were convinced that the circulation through it was perfectly restored; and the only extraordinary appearance which we observed on the artery, was a slight impression made on its external surface by the ligatures. The external wound was then sewed up.

66

August 9. The animal died this evening, in consequence of profuse secondary hæmorr hage from one of his femoral arteries, on which an experiment had been performed. "Dissection. On cutting away the liga tures in the integuments covering the carotid, we found a quantity of thin pus in the wound, extending down to the artery, which however was covered and surrounded by a very thick layer of lymph, not only on the part on which the ligatures had been applied, but also about an inch below, and an inch and a half above. In proceeding to cut open the artery, I only expected to find its middle and internal coat cicatrized, and its canal more or less completely pervious; but, to my great astonishment, it was completely obstructed and filled up with lymph, which not only adhered to, but appeared to form one substance with, the parietes of the artery. The lymph at each of its extremities appeared rather of a dark red colour, in consequence of the adhesion of some red particles."

The canal of the artery was not entirely obstructed in one or two other experiments, in which only one ligature was, used. From this fact, ascertained in regard to the arteries of brutes, Dr. Jones has suggested some practical inferences, in the form of queries, which bear every appearance of probable advantage and success. He observes, that

provements which have been introduced in the operation of aneurism, may perhaps appear to most surgeons to have rendered that ope ration sufficiently simple and safe: but if it nal of an artery of the human subject, in the be possible to produce obstruction in the caabovementioned manner,may it not be advantageously employed in the cure of aneurism? inasmuch as nothing need be done to prevent the inmediate union of the external wound. The operation may then be considered merely as a simple incised wound. May not this mode of obstructing the passage of blood through the arteries be also used with advantage in cases of bronchocele? There may be other cases in which it may prove useful, but I shall not dwell longer on what may appear to be premature suggestions and queries.—It is enough for my present purpose to have pointed out the true principles on which the ligature acts." p. 135.

The subject of Chap. IV. which is illustrated by fourteen experiments, relates to the process of adhesion, and the changes which an artery finally undergoes, in con sequence of the application of the ligature to the cut extremity of it, or of two ligatures, between which a complete division is made. This part of the subject is foundceding chapter, and therefore will not ed altogether on the doctrine of the predetain us. It is worthy of consideration by the practical surgeon.

The concluding Chapter relates to "the improper form and application of the ligature, as tending to produce secondary hæmorrhage." The object of the ligature is not only a temporary suppression of hæmorrhage, but a permanent security against its return. Now to obtain the speedy and complete adhesion of its internal coats, the ligature should be such, and so applied, that the wound in these coats may as nearly resemble a simple incised wound as possible. The ligature therefore, should neither be broad and flat, nor irregular in its surface. Coagulating lymph appears to be effused only at the points which are cut: and the author believes, that if the ligature does not completely cut through internal and middle coats all round the artery, complete adhesion cannot take place between its internal surfaces, and therefore secondary hemorrhage will take place as soon as the ligature has ulcerated through any part of the artery, and that of course it will become more frequent and copious as the process of ulceration ad

vances.

without any fear as to its coming too speedily away.

The plates afford clear and distinct illustrations of the different states of the arteries, found in the different experiments on dissection.

Upon the whole this experimental essay, if it do not bring much of absolute novelty before us, will conduce at least to render our ideas on the subject more distinct and definite; and will enable us, in a great measure, to estimate the value,

and to discriminate the truth and the er rors, of the observations relative to the subject, which are already on record; and thus to remove much confusion and un. certainty which hung over it. The experiments appear to have been conducted with caution and dexterity, and are related with simplicity and apparent fidelity ;— they are sufficiently numerous to admit of a satisfactory generalization, and no deduction is attempted to be inferred which the facts do not obviously warrant.

IN a dedication addressed," to the readers of the Annals of Medicine," written by Dr. Duncan senior, we are informed that he has resolved to close his periodical labours. We cannot but feel regret at taking leave of an author, who has presented to the public an annual volume for 28 successive years; but we are happy to find that he still proposes to take an active share in the conduct of a new work, which is perhaps already familiar to many of our readers, "the Edinburgh Medical and Surgical Journal."

The volume before us consists, as usual, of an analysis of books, original essays, and articles of medical news. The first section, the analysis of medical books, which occupies above half the volume, we shall pass over with merely remarking, that the most interesting articles are those inwhich the opinion latterly stated by M. Seguin, respecting the febrifuge principle of cinchona, is examined and refuted. We must indeed express our astonishment that such an hypothesis should be proposed by a man so distinguished for scientific research.

The original communications commence with a valuable essay written by Dr. Kellie, entitled, "Observations and Experiments on the Electricity of Animals." Galvani himself, in the early part of his researches, discovered that contractions might be excited in the muscles of a frog, without the intervention of metals or other foreign substances, merely by bringing different parts of the body into contact; experiments of a si milar kind were afterwards performed by Humboldt, and more lately were repeated and extended by Aldini. These experiments prove that the matter, whatever it be, which produces contractions, must reside in the animal itself, and that

they must therefore be considered as entirely distinct from those operations in which the electric fluid, generated by means of the pile or the trough, is passed through a limb, and thus excites it to action. It was to this class of phenomena that our author particularly directed his attention, and he has accordingly present ed us with a train of well-conducted and sufficiently diversified experiments, on the contractions produced by bringing into contact the nerves and muscles of the same animal under different circumstances. The experiments are detailed in a perspicuous manner, and ample directions are given to those who may be desirous of repeating them. To analyze all the experiments would carry us beyond our usual limits, but we shall present our readers with the consequences that are deduced from them, which are highly interesting, and which, we may add, the experiments fully authorize.

"In general, we may conclude from these experiments:

1. That the muscles of the extremities of prepared frogs, are convulsed when brought to touch their denuded nerves.

"2. That they are also, and often more powerfully, convulsed, when the circle beed by other animal conductors. But, if an tween the muscles and the nerves is complet isolating substance be interposed, no muscular contraction can be produced.

"3. That the substances employed to close the circle, do not excite contractions in the ratio of their conducting powers.

"4. That convulsions take place only in those parts whose nerves are touched," although other excitable parts enter into the

circle.

5. That the preparation of the animal, absolutely necessary for the success of these experiments, consists in isolating the nerves, so that no other conducting substance be con

7. That when the nerves are tied, нO

convulsion can be excited by completing the circle with the nerve above the ligature. "8. The matter put in motion, and producing muscular contraction in these experiments, bears every resemblance to the electric fluid. For it is conveyed by water, the bodies of animals, the metals, &c., and is arrested by glass and sealing-wax. It passess rapidly through the bodies of animals. It excites convulsions, which, however, cease when the parts are kept steadily in contact, i. e. when an equilibrium is produced.

9. By the preparation of the frog, this matter is accumulated in the nervous system, and is put in motion when the circle is formed, by the immediate contact of the muscles and nerves, or by conducting substances interposed between these, or between muscular parts connected by the nerves only.

10. That the matter thus put in motion, produces contractions only when it passes to the muscles through the nerves.

"11. That the fluid thus put in motion, acts as a stimulus to the nervous energy.

"12. But it cannot be the nervous energy itself: 1. Because no accumulation can take place in the living entire body, the nerves being every where surrounded by conducting fluids and solids. While, for the success of these experiments, it is absolutely necessary that the nerve be isolated; no contractions can be produced, even in the prepared animal, when immersed under water, or when the nerves are surrounded by any good conducting medium.-2. Because the nervous power is excited by chemical, or by mechanical stimuli: and, on the other hand, is destroyed by opium, and other poisons, which cannot he imagined to act on the electrical

fluid."

The paper concludes with some observations upon the theories proposed by Humboldt and De la Metherie; the former of whom supposed that the galvanic fluid was secreted in the brain, and carried by the nerves to the muscles; the latter, that the galvanic fluid is itself the vital principle. To both these hypotheses Dr. Kellie opposes objections which we think decidedly prove their futility; but we forbear to enlarge upon the subject, as we apprehend there are few persons in this country who are disposed to attach any credit to them.

The second paper contains the history of a singular affection of the right leg, accompanied with symptomatic epilepsy, which was cured in the Royal Infirmary of Edinburgh by the use of galvanism," The case, which proceeds from the pen ANN. REV. VOL. IV.

of Dr. Duncan senior, is detailed at full length, and certainly deserves attention. An injury appears to have been received by the nerves of the leg, in consequence of which, not only the functions of the part were materially decayed, but frequent epileptic fits were induced. The disease was entirely removed: and it may be fairly assumed that the cure was effected by the application of the galvanic influence. A certain degree of uncertainty always attaches to cases of this description, where the nervous system is the principal seat of disease. The almost unlimited power which the imagination possesses over such affections, should, in every instance, induce us to be extremely cautious in our conclusions respecting the physical effects of remedies; the cures performed by Dr. Haygarth, with his fictitious tractors, were even more decisive than that now under consideration.

We

would not, by this observation, be thought to insinuate any thing unfavourable to the judgment or candour of Dr. Duncan; we think indeed that the case, evidently depending upon a local cause, was one in which the application of the electric fluid cidedly of opinion that this agent may be was especially indicated, and we are deapplied with the most effect as extricated from the galvanic apparatus.

We are next presented with an account of three cases of hydrocephalus chronicus, by Dr. Munro junior: the first is very accurately described, and is accompanied by an engraving. It has been observed that the subjects of this complaint have frequently come into the world with difficulty, and it has been questioned whether the severity of the labour should be considered as the cause or the effect of the disease; we agree with the author in thinking the latter supposition the more probable. The phænomena of this complaint may throw some light upon a point which has been much agitated by physiologists, whether the brain is to be considered as moulding and fashioning the skull, or whether the skull limits the form and size of the brain. We may infer, from such cases as those before us, that the figure and size of the skull is dependant upon that of the brain; and that, to its power of yielding to the pressure of the internal parts, may be attributed the longer duration and comparative mildness of the symptoms, when the disease takes place in those subjects, where the different lines which compose the skull are not yet firmly united together. The paper con

3 G