In those cases of acute abscess of the palm of the hand, fore-arm, arm, thigh or leg, where the matter is situated beneath or centrad of the fascia, there is generally a dull cutaneous inflammatory discoloura tion, and an (edematous feeling, which, with the other symptoms already enumerated, indicates the presence of matter. In such cases the fascia must be freely divided with the bistoury. An oedema tous boggy sensation is the best index of matter being secreted, yet it is often exceedingly difficult to distinguish its presence; the ludas crudilus is a valuable acquisition to a surgeon. When an acute abscess is examined, it is coated with coagulable lymph of a smooth membranous-looking. ash colour, which is termed the sac or cyst, and adheres by a vascular cushion to the surrounding cellular substance, the latter of which, in the vicinity of the abscess, is more dense and vascular; and its cells are closed with coagulable lymph. In this vas cular cushion and stratum of coagulable lymph, the capillary vessels modified to secrete the purulent matter are situated, together with the nerves, veins, and absorbents. In all abscesses, a secreting and absorbing action is going on. A remarkable cir cumstance is that an abscess advances almost al ways to the surface of the body, which has been attempted to be explained on the principle of plants growing towards the light. It appears, however, more probable from the skin offering less resist ance, for when matter is deposited beneath a fascia, it burrows in all directions. The matter secreted in an acute abscess, occurring in a healthy consti tution, is named pus or purulent matter, and is of a yellow cream colour, and about the consistence of rich cream. For its chemical properties the reader is referred to the article CHEMISTRY. Pus slightly irritates the contiguous skin of an abscess or ulcer, and even the granulations : therefore, from these fretting qualities, it ought to be absorbed by lint and tow as soon as secreted.
An abscess, when freely opened and dressed daily with simple dressings, gradually fills up by the formation of suppurative papill? or granulations, and when these arrive to be nearly on a level with the skin, it is generally termed an ulcer : an ulcer, therefore, is simply a diseased, or abraded secreting surface, (for there arc numerous healthy secreting surfaces,) and has been correctly defined by authors to be a solution of continuity in any of the soft parts of the body, attended with a secretion of pus or some other discharge. Another definition, but not so perspicuous or correct, is, that it is a chasm formed on the surface of the body by the removal of parts back into the system by the action of ab sorbents ; and a third is, a granulating surface se creting matter, the last of which is most satis factory. The ulcer consequent on an acute abscess occurring in a healthy constitution, is named a healthy ulcer, from its being a process of nature to repair the breach of continuity, but the same is ap plicable to the syphilitic ulcer. Simple, conse quently, is a better appellation than healthy to this kind of ulcer, as no diseased action can be said to be healthy. It is termed the simple purulent ulcer ;' and 'ulcers in parts which have sufficient strength to carry on the actions necessary for their recovery.' In the Philosophical Transactions for 1819, Sir E. Home has detailed some most in genious microscopical observations on the conver sion of pus into granulations, by the extrication of carbonic acid gas from coagulated pus, forming , tubes or canals, which are filled with red blood, and thus connected with the circulation : this, how ever, appears too chemical a process. In this spe
cies of ulcer, the granulations are bright red coni cal points, regularly formed, numerous, firm and distinct ; and the matter secreted by them is pus hi a moderate quantity. These granulations, when they arrive at the level of the skin, form a thin film or skin, which begins at the edge, if the structure of the skin has been destroyed, and spreads over the sore, and in the middle, or all over the sore, if the cutaneous tissue is preserved, as is beautifully exemplified in the ulceration supervening to a gentle scald. The treatment of this simple ulcer is merely to absorb the pus, and afford support to the edges and the cutaneous circulation ; dry lint, therefore, is often preferable to that spread with simple oint ment, and should be notched towards the centre in order to give exit to the pus. For the same reason a pledget or compress of tow should be put over it, and a roller gently applied above. The great art in the treatment of this ulcer is not to stimulate it, and to preserve the new skin when formed. On renewing the dressings, the old should be tho roughly softened with warm water before removal. When the ulcer occurs in the leg, which, from its exposed and depending situation, is most subject to ulcers, the roller should be applied from the toes to the groin, as exemplified in fig. 1, of Plate DXVI : and the patient should keep as much as possible in the horizontal position. Various sub stances are used for bandages, as calico, linen, and flannel.
This simple or healthy ulcer is very easily in flamed or irritated, and then assumes the name of the irritable ulcer, or the ' inflamed ulcer,' or ' ul cers in parts whose actions are too violent to form healthy granulations, whether this arises from the state of the parts or of the constitution,' and is char acterized by the sore becoming hot and painful, and the granulations of a dark red colour, approaching to purple, very small, and scarcely distinguishable, the edges of the sore thin, ulcerated, or phagedenic, having a worm-eaten appearance, and the skin around the ulcer inflamed, of a dark purple colour. The secretion is thin, and either bloody, dirty white, or of a green colour ; and is so acrid as to excori ate the surrounding skin, and even the granulations themselves. The surface of the sore is occasionally of a brown instead of a purple colour, while at other times white or ash•coloured ; and there are fre quently irregular elevations and depressions, as if they were excavated by the matter. This species of ulcer is easily produced by the most trifling ex citing cause. The treatment of this irritable ulcer is by the application of large anodyne fomentations and poultices, low diet, and absolute rest in the horizontal position, until the inflammatory action is completely subdued, which is indicated by the absence of the pain, and the diminution of the in flamed colour of the surrounding skin ; by the edges becoming defined and clean ; by the sore becoming more florid in colour, and by the secretion becom ing creamy and purulent ; or, in other words, by the sore presenting the characters of the simple ul cer. For the first two or three days simple oint ment should be used, and a roller applied. The diet and exercise ought to be slowly increased.