232 



ARTERY, PATHOLOGICAL CONDITIONS OF. 



and, lastly, a large and important vessel in 

 this condition has been tied without its being 

 crushed or broken down short, and being fol- 

 lowed by consecutive haemorrhage. From 

 these observations some reasonable doubt may 

 be entertained of these deposits being the 

 result of inflammation, more particularly as, 

 at the period of life alluded to, there is an 

 evident disposition to the formation of earthy 

 deposits in many structures and organs as well 

 as in the arteries. 



When a large aneurism runs its course with 

 great rapidity, an opportunity is frequently 

 afforded of observing a condition of the vessel 

 most favourable to the production of the dis- 

 ease, and which therefore may be considered 

 as one of its direct or immediate causes. The 

 vessel in this case, on being slit up, exhibits 

 its internal lining membrane less smooth and 

 polished than in its natural state ; its colour is 

 changed to a deep roseate carmine, and it sepa- 

 rates from the subjacent fibrous coat with com- 

 parative facility. This latter structure is also 

 changed in colour, but not to so bright a red 

 as the other. Between these coats, but more 

 closely attached to the internal, (for they peel 

 off with it,) are numerous specks of a soft 

 steatomatous material of a white or pale grey 

 colour, presenting, on a superficial inspection, 

 somewhat of the appearance of the calcareous 

 deposit already spoken of. An artery in this 

 condition has lost more or less of its elastic 

 properties; it is distended, and its calibre 

 increased equally around. As the arteries are 

 always full, the impulse of every new wave 

 of blood driven on the greater quantity con- 

 tained within the distended vessel increases its 

 apparent pulsation, for it is in the diastole or 

 expanded condition of the artery that the pulse 

 is felt. This loss of elasticity must obviously 

 weaken the vessel, and cause it to be less re- 

 sisting: a fact that can be proved by expe- 

 riment after death, when an artery so circum- 

 stanced will be found to yield and tear under 

 a distending force that would have little effect 

 on it if in health, and will explain how an 

 apparently trifling exertion may produce aneu- 

 rism in one man, whilst numbers of others 

 exposed to similar or even greater violence 

 escape safe and unharmed. 



If arteritis can be justly considered as an 

 immediate cause of aneurism, it follows that 

 any thing tending to produce this condition of 

 the vessel will predispose to the disease. An 

 investigation of the natural history of this 

 affection would, therefore, prove equally useful 

 and interesting, but as yet a sufficient num- 

 ber of facts have not been collected from which 

 any useful practical induction can be drawn. 

 The experience of an individual cannot be 

 sufficient to establish a fixed and general posi- 

 tion, but may be valuable if it induces others 

 to a similar line of investigation, in order to its 

 being verified or contradicted ; and from a 

 minute attention to the previous history of 

 several cases, I have frequently been able to 

 connect intemperance, particularly in the use 

 of spirituous liquors and repeated or in-con- 

 conducted courses of mercury, with the pro- 



duction of arteritis. How far these can explain 

 the comparative infrequency of the disease in 

 females and its prevalence amongst men sub- 

 ject to exposure, and too often of reckless and 

 dissolute habits, must be determined by future 

 observation ; but, in corroboration of the latter 

 part of this opinion, it may be remarked, that 

 few old persons are subjected to a course of 

 mercury that do not perish shortly after by the 

 bursting of a bloodvessel, of apoplexy, or 

 haemoptoe most frequently. 



When arteritis has proceeded to the extent 

 of producing these steatomatous deposits, if 

 aneurism is not inevitable, it is certainly very 

 likely to ensue. In some instances the loss of 

 elasticity is so great as to cause all the coats 

 of the vessel to yield and become distended 

 into the sac of a true aneurism : in others, 

 (and far more frequently) the process of ulce- 

 ration commences, the lining membrane cover- 

 ing one of these spots first becoming soft, 

 then exhibiting a distinct ulcer which proceeds 

 from within, eroding the middle coat either 

 through its entire thickness to the cellular, 

 which is then easily distended into the aneu- 

 rismal sac ; or so far as that it shall be likely 

 to give way and tear under a trifling shock, 

 even under the impulse of the circulation. 

 In the pathological collection of the medical 

 school of Park-street, Dublin, there are pre- 

 parations exhibiting these forms of aneurism 

 and the different stages of dilatation, of soft- 

 ening, and of ulceration in the most satisfactory 

 manner. 



Circumscribed false aneurism, When a 

 person experiences a sensation as if something 

 had given way or been torn within his limb, 

 or even without such previous warning, per- 

 ceives a small hard, pulsating tumour situated 

 somewhere immediately on the course of a large 

 or leading artery, it is to be suspected that an 

 aneurism has formed. And this suspicion is 

 confirmed, if the tumour becomes larger or 

 smaller, according to the diastole or systole 

 of the artery, or is diminished by pressure, or 

 almost disappears if the patient should happen 

 to faint. If pressure be applied on the trunk 

 of the artery between the tumour and the 

 heart, its pulsation ceases, its size is sensibly 

 diminished, and it becomes soft and flaccid; 

 if on the farther or distal side of the tumour, 

 its size is increased, and its throbbing rendered 

 far more evident. The pulsation is said to 

 become more faint in proportion to the growth 

 of the tumour, and this, though generally true, 

 is not so universally, for this symptom will 

 presently be found to be influenced by a num- 

 ber of circumstances, such as the blood within 

 the sac being fluid or coagulated, the situation 

 and depth of the tumour within the limb, and 

 the coverings of fasqia it may possess. In 

 most instances there is a peculiar whizzing 

 sound, plainly perceptible on applying the ear 

 or a stethoscope to the tumour, termed by the 

 French the " bruit de soufflet;" but its pre- 

 sence or absence is by no means pathogno- 

 monic, foi it m t \y be artificially produced by 

 pressure on the trunk of any large artery. 



On examining a circumscribed aneurism 



