Suppuration is a natural termination of inflammation; and the ulcerative action is invariably induced by the suppurative, unless this remain chronic. The ulcerative action is to be considered as in part a restoration of the natural one; for we find, that it produces a restoration of the structure, granulations being formed by the vessels which formerly supplied the organic particles, whilst the interstitial vessels still yield a morbid fluid, called pus; but this they cease to do, whenever they again are placed in the natural situation; that is to say, whenever they become covered with the granulations, or are rendered interstitial. In proportion, then, as granulations are formed, a certain number of vessels are rendered interstitial, so that the discharge gradually diminishes, until at last it ceases; for, when we come to the formation of a cuticle, we have very few interstitial vessels left, the skin having naturally few. At this time, the one set of vessels having completed their action, and the part being restored, the other also resume their action, and a thin exhalent fluid is thrown out by the new cuticle, which keeps it soft and moist, and which is the natural insensible perspiration. The action of the two sets of vessels, then, is dependent on each other; and, whenever one is diseased, the other becomes also more or less so. GENUS I. _Of the Healthy Ulcer._ From these remarks, as well as from those which were formerly made, it will appear, that a healthy ulcer has a natural tendency to heal, and that we ought only to be careful not to interrupt the natural progress, nor allow the action to flag.