Jacksonian prize was adjudged by the Royal College to Mr Hodgson for an Essay, which has laid the foundation of the excellent treatise now before us. In separate parts, the very author treats in succession, 1st, of the diseases of arteries in general; 2d, of aneurism; 3d, of wounded arteries; and 4th, of the diseases of veins. Besides being the subject of inflammation, ulceration, and sphacelation, like other structures, the arteries are liable to other and peculiar morbid changes, to cartilaginous and steatomatous thickenings of their internal coat, and to a deposition of atheromatous and calcareous matter. And these changes are very commonly the forerunners of the more formidable disease of aneurism. But, before entering on the subject of aneurism proper, Mr Hodgson directs our attention to the cases of preternatural dilatation of the arteries. This disease is different from aneurism, as all the coats of the vessels are uniformly dilated, without any breach of their continuity. Its most frequent seat is the ascending portion, and arch of the aorta, though it has been observed in the thoracic and abdominal aorta, and at the divisions of the carotid and iliac arteries. The pouch or sac which is thus formed, is commonly thickened, and covered with atheromatous and calcareous depositions ; but this dilatation seldom if ever is found to contain those lamellated coagula which are so generally discovered in the true aneurismal sac; which last, on the contrary, is not often found interspersed with calcareous or ossific deposits like those pouches or dilatations, in which all the coats of the artery are entire. A true aneurism may be, and sometimes is, found engrafted upon a sac of simple dilatation.

Our readers are aware, that the observations of Scarpa have led to the conclusion, that, in aneurism, the formation of the tumour is preceded by a rupture or breach of the internal and middle coats of the artery, and that the sac is formed by the consequent dilatation of the outer coat, and cellular sheath of the vessel.

After having ascertained the fact, therefore, that the whole circle of an artery is found to be preternaturally dilated, in a great many cases, without laceration or destruction of any of its coats, it seems to us a mere affair of arbitrary definition, whether such cases shall be called aneurism or not; and especially, it seems to us, that Mr Hodgson, after describing this case of preternatural dilatation as a distinct disease, and beginning his section on aneurism with a definition, limiting its interpretation to the case in which the internal and middle coats have given way, would have saved to himself, and to his readers, some little confusion, by maintaining this distinction throughout. Instead of

which, he resumes the consideration of dilatation with integrity of the coats of the artery, and reasons upon the subject in a way which leaves us, in some degree, at a loss to know whether he would class it with aneurism or not. Thus, he begins with stating the question, "Does aneurism ever consist in a general or partial dilatation of all the coats of an artery, or is it constantly produced by the destruction of all, or most of the coats?"

That disease, indeed, already described by him in a separate section, and said to consist in a preternatural dilatation of the whole circle of an artery, and not in a partial or lateral distension of its coats, Mr Hodgson continues to disunite from aneurism. But the case of a partial dilatation of the coats without rupture, he seems inclined to consider as less separable from ordinary aneurism; and he maintains, that, in a great proportion of aneurisms, the disease has commenced in a partial dilatation of the coats of the artery, although, in the progress of the disease, the internal coats do at length give way. In the generality of cases, indeed, he allows with Scarpa, that the formation of the aneurismal tumour is preceded by rupture of the internal and middle coats of the artery. But very many, he contends, have their origin in previous, general, or partial dilatation of all the coats.

"Those aneurisms which are situated at the origin of the aorta, are generally formed by dilatation of the coats of the vessel. The internal surface of the sac, in most instances, exhibits some of those morbid alterations which are peculiar to the internal coat of an artery. The mouth of these sacs is generally larger than any other part of the cavity, and there is not that circumscribed margin between the artery and the sac, which is constantly met with where aneurism is formed by destruction of the coats of the vessel."

Mr Hodgson has seen this partial dilatation, in almost all the arteries which are subject to aneurism. Such dilatations frequently precede the formation of aneurism in the arteries of the extremities. The cases and observations brought forward by Mr Hodgson, as well as the disputes which have always existed amongst anatomists on this subject, leave no doubt as to the existence of these pouches, and dilatations of the coats of an artery without any rupture; and all that our author seems to contend for is, that many aneurisms have their origin in such general and partial dilatation.

66 1st, Numerous aneurisms are formed by destruction of the internal and middle coats of an artery, and the expansion of the external coat into a small cyst, which giving way from distension, the surrounding parts, whatever may be their structure, form the remainder of the sac. 2dly, Sometimes the disease commences in the

dilatation of a portion of the circumference of an artery. This dila. tation increases until the coats of the vessel give way, when the surrounding parts form the sac, in the same manner as when the disease is in the first instance produced by destruction of the coats of an artery."

The original question, however, proposed by Mr Hodgson, "Does aneurism ever consist in a general or partial dilatation of all the coats of an artery; or, is it constantly produced by the destruction of all or most of these coats?" seems thus rather to be gotten rid of, than answered.

It seems, however, to be our author's conclusion, that, although aneurism has often its origin in such dilatation, the case of dilatation ought not to be considered as one of aneurism, till the internal and middle coats of the artery have given way. There is one thing peculiar to this restricted case of aneurism which deserves notice, the deposition of the fibrous portion of the blood in concentrical laminæ upon the internal surface of the sac." It is almost universally found in aneurisms in which the coats of the artery have given way, but in those sacs which consist in a general and partial dilatation of the coats of the vessel, I have never met with it."

Aneurism, and those diseases of the coats of the arteries which precede its formation, occur much more frequently in men than in women. And the following table exhibits the comparative frequency of aneurisms in the two sexes, in different cases of the disease, in which our author has had an opportunity of seeing his patients during life, or of examining the parts soon after death.

Having considered most of the questions connected with the nature and formation of aneurisms, and having pointed out the

symptoms and diagnosis of the disease, Mr Hodgson gives us some very important and highly interesting observations on the spontaneous cure and medical treatment of aneurism, a subject which, he observes, might, from the bold and successful operations now performed with so much precision, appear superfluous. But the processes of nature are the lights of surgery, and the guides of the operator; and when the disease is beyond the reach of surgery, as in aneurism within the cavities of the thorax and abdomen, the attempts of nature sometimes prevent a fatal termination, and when her processes are understood, they may be assisted by medical treatment.

The processes by which the spontaneous cure of aneurism is effected, are thus stated by Mr Hodgson.

First, The removal of the whole tumour by sphacelation, in consequence of the extreme inflammation excited by the distension of the surrounding parts.

Secondly, The tumour assuming such a position, as to obliterate by its pressure the superior or inferior position of the artery communicating with the sac.

Thirdly, The gradual deposition of the fibrine of the blood in the aneurismal sac and the artery leading to it, so as to render them impervious, and allow a subsequent process, by which the tumour is removed.

Mr Hodgson illustrates all those modes of spontaneous cure by cases and observations, and deduces from them the circumstances under which they may respectively take place. The last mode is by far the most frequent and the safest, and that which art is most capable of assisting. Indeed, in all our operations for aneurism, Mr Hodgson shews, that it is by this mode the cure is ultimately effected, though the unassisted efforts of nature are sometimes sufficient for the purpose. Numerous instances, he observes, are recorded, in which this process is noticed as having taken place; but its importance in the cure of aneurism, and the circumstances which influence its accomplishment, do not appear to have received that attention which, in a practical point of view, they deserve.

The process consists of the three following stages, according to the result of Mr Hodgson's inquiry: First, The cavity of the sac is gradually filled with layers of coagulum.. Secondly, The circulation through the vessel is in most instances prevented by the extension of this coagulum, to the origin of the next important ramifications that are given off by the artery, from which the disease originates.

Thirdly, The coagulum is gradually absorbed, and the ar

tery and the sac contract, until the one becomes an impervious cylinder, and the other a small fleshy tumour.

Thus, where the circulation can be carried on by the collateral branches, a perfect cure of the aneurism is effected, and life is preserved. But, in internal aneurisms, in aneurisms of the aorta, particularly of the arch or ascending portion of that vessel, the completion of this process in all its steps would not be so fortunate. But here nature proceeds no farther than she can be useful; and Mr Hodgson, by a selection of cases and observations has shewn, that a deposition of coagulum may take place in an aneurismal sac to such an extent, as entirely to preclude the communication between its cavity, and that of the artery from which it originates; that a sac thus filled with coagulum, cannot prove fatal by rupture; and that the gradual absorption of its contents, and the consequent contraction of the sac, may proceed to such an extent as to effect a cure of the disease, without any obstruction taking place in the calibre of the vessel from whence it originated.

A true aneurism commonly communicates with the canal of the artery by a small and lateral opening, the aneurismal sac soon begins to exhibit the formation of those deposits of concentric layers of coagulable lymph;-and, by the successive depositions of those layers the sac is strengthened, and, in some cases, filled up and rendered solid; and then the process of condensation and absorption takes place, and an aneurismal tumour, which had risen out of the thorax, beaten furiously, and threatened destruction, gradually retires, and at length disappears. It is consoling to know, that even under such an alarming and generally fatal state of things, there is this chance of escape. The cases reported by Morgagni of the cures performed by Valsalva and Albertini ;-those related more lately by Pelletan, and other continental surgeons and physicians, afford examples of this fortunate interruption to the fatal termination of aortic aneurism. Several cases, in illustration of the completion of this fortunate process in different orders of arteries, are related by Mr Hodgson. We select the two following, as having occurred in the aorta itself:

"A miller, about fifty years of age, had, for five years before his death, been afflicted with severe symptoms of asthma. Various medical men considered him as labouring under that peculiar asthma to which those who follow his occupation are subject. His symptoms, however, were always relieved by copious bleedings. The above was all the information which could be procured relative to his disease, -when the body was examined. The lungs were perfectly healthy. A small aneurismal sac originated from the posterior part of the arch