but the term has been applied to every collection of matter effused, and changed by stagnation in an inclosed cavity. The matter of abscesses, and of the ulcers following them, is various, according to the nature of what is effused, and which may be, 1, A matter thinner than serum; 3, A quantity of red globules; 4, A matter furnished by particular glands seated in the part; 5, A mixture of matters from different sources, changed by peculiar fermentation. It is the second only which affords a proper pus; the effusion whereof, whether in suppurating parts or ulcers, seems to be the peculiar effect of an inflammatory state of the vessels; and for this reason it is, that, when ulcers do not produce a proper pus, a circumstance always absolutely necessary to their healing, we, in many cases, bring the ulcers to a state of proper suppuration, by the application of stimulants exciting inflammation, such as balsams, mercury, copper, &c. 255. When the matter effused into the cellular texture of an inflamed part, is tainted with a putrid ferment, this produces, in the effused matter, a state approaching more or less to that of putrefaction. When this is in a moderate degree, and affects only the fluids effused, with the substance of the cellular texture, the part is said to be affected with CANGRENE; but if the putrefaction affect also the vessels and muscles of the part, the disease is said to be a SPHACELUS. 256. A gangrene, and its consequences, may arise from a putrid ferment diffused in the mass of blood, and poured out with the serum effused, which it operates upon more powerfully while the serum is stagnant, and retained in the heat of the body but it may also arise from the peculiar nature of the matter effused being disposed to putrefaction; as particularly seems to be the case of the red globules of the blood effused in a large quantity. In a third manner also, a gangrene seems frequently to arise from the violent excitement of the inflammation destroying the tone of the vessels, whereby the whole fluids stagnate, and run into putrefaction, which taking place in any degree, destroys still further the tone of the yessels, and spreads the gangrene. 257. In inflammation, the tendency to gangrene may be apprehended from an extreme violence of pain and heat in the inflamed part, and from a great degree of pyrexia attending the inflammation. The actual coming on of gangrene may be perceived, by the colour of the inflamed part changing from a clear to a dark red; by blisters arising up on the part; by the part becoming soft, flaccid, and insensible; and by the ceasing of all pain while these appearances take place. As the gangrene proceeds, the colour of the part becomes livid, and, by degrees, quite black; the heat of the part entirely ceases; the softness and flaccidity of the part increase; it loses its consistence, exhales a cadaverous smell, and may then be considered as affected with sphacelus. 258. Gangrene is thus a third manner in which inflammation terminates: and the schools have commonly marked a fourth termination of inflammation; which is, by a scirrhus, or an indolent hardness of the part formerly affected with inflammation. This, however, is a rare occurrence, and does not seem to depend so much upon the nature of inflammation, as upon the circumstances of the part affected. It is in glandular parts chiefly that scirrhosity is observed; and it is probably owing to the parts readily admitting a stagnation of the fluids. I have observed, that inflammation seldom induces scirrhus; but that this more commonly arises from other causes; and when inflammation supervenes, which it is sooner or later apt to do, it does not so commonly increase as change the scirrhosity into some kind of abscess. From these considerations, it does not seem necessary to take any further notice of scirrhus as a termination of inflammation. 259. There are, however, some other terminations of inflammations not commonly taken notice of, but now to be mentioned. One is, by the effusion of a portion of the entire mass of blood, either by means of rupture or of anastomosis, into the adjoining cellular texture. This happens especially in inflammations of the lungs, where the effused matter, by compressing the vessels, and stopping the circulation, occasions a fatal suffocation; and this is perhaps the manner in which pneumonic inflammation most commonly proves fatal. 260. Another kind of termination, is that of certain inflammations on the surface of the body, when there is poured out under the cuticle a fluid, which being too gross to pass through its pores, therefore separates it from the skin, and raises it up into the form of a vesicle containing the effused fluid; and by which effusion the previous inflammation is taken off. 261. Besides these already mentioned, I believe there is still another manner in which inflammation terminates. When the internal parts are affected with inflammation, there seems to have been almost always upon their surface an exudation, which appears partly as a viscid concretion upon their surface, and partly as a thin serous fluid effused into the cavities in which the inflamed viscera are placed. Though we have become acquainted with these appearances only, as very constantly accompanying those inflammations which have proved fatal; it is however probable, that like circumstances may have attended those which were terminated by resolution, and may have contributed to that event. It is in favour of this supposition that there are instances of pneumonic inflammation terminating in a hydrothorax. SECT. IV. Of the remote causes of inflammation. 262. The remote causes of inflammation may be reduced to five heads. 1, The application of stimulant substances; among which are to be reckoned the action of fire, or burning. 2, External violence operating mechanically in wounding, bruising, compressing, or over-stretching the parts. 3, Extraneous substances lodged in any part of the body, irritating by their chemical acrimony or mechanical form, or compressing by their bulk or gravity. 4, Cold, in a certain degree, not sufficient immediately to produce gangrene. 5, An increased impetus of the blood determined to a particular part. |