The phagedena is a suppurating sore, dependent upon the application of a peculiar contagion. No granulations are formed, but both sets of vessels yield a thin fluid. The surface of the sore has a jagged appearance, dependent upon the irregularity of the absorption, and not upon the deposition of organic particles, or granulations. The colour of the surface is dark, but clear, or fiery. The surrounding integuments are erysipelatous. The discharge is thin and serous, and the pain considerable. This is divisible into two varieties: First, the true phagedenic, which does not go deeper than the skin, but spreads rapidly along the surface. This kind frequently stops in its progress suddenly, and skins over as fast as it spread. Second, the noma, or penetrating phagedena, which extends deeply, penetrating sometimes perpendicularly down through the cellular substance to the muscular fascia; at other times, proceeding more irregularly, penetrating deeper at one part than another, and having its margins ending less abruptly in the neighbouring skin. This never cicatrizes rapidly; but, sometimes, when the sore assumes a healing appearance, it suddenly becomes again diseased, and a considerable portion sloughs off. The alternation of proceeding a certain length in the cure, and relapsing, is frequently repeated, and often renders the disease very tedious. The best application for the common phagedena is an ointment consisting of an ounce of ung. resinos. and a drachm of red precipitate. The application of caustic to the surface also frequently stops the progress of the disease. The hepatized ammonia, much diluted, is also very useful as a lotion. The penetrating phagedena is more difficult to cure; for, even after the diseased action is removed, the ulcer remains in an irritable, or overacting date. The application which I have found most useful is powdered opium, mixed with simple ointment, in the proportion of two drachms of the former to an ounce of the latter. After the phagedenic action ceases, the sore must be treated according to the genus of simple ulcer to which it belongs. When the sores seem to pursue their ravages obstinately, the most effectual mean of stopping their progress (until we discover a specific remedy, or one which can change the nature of the action), is to apply the caustic to every part, and so freely, as to produce a pretty thick slough. Whenever this appears to separate, precipitate must be applied, in order, if possible, to prevent the recurrence of the diseased action.