When, by the use of the remedies already mentioned, the progress of the gangrene is stopped, the ulcerative action is induced in the part immediately adjoining to the dead portion, and a red line of separation appears. By means of this ulcerative action, which takes place in every point where the mortification stops, the dead part is separated from the living, and comes away as soon as the bonds of dead muscular fibres, tendons, &c. which unite them, are destroyed by putrefaction. When this separation takes place, or when it is advanced so far as to permit us to accelerate it by dividing the loose tendons, &c. the exposed part must be dressed as an ulcer, or wrapped up in a poultice of the same temperature with the human body. If, however, the disease have penetrated deep, and destroyed the limb so much as to render it impossible to cure it, or useless, if it were possible, then amputation must be performed; but this, whatever desire the patient may express, must not be practised until the mortification be fully stopped, and the ulcerative action induced; because, if performed sooner, the mortification seizes the stump, and the patient is quickly killed. The system is likewise in such a state as to be unable to sustain the action which is necessarily produced by the operation. It is even improper to cut too near the diseased portion; because the parts here, although the mortification be stopped, are so weakened, that they are less apt to unite. The vessels often break out soon after they are tied, and a new mortification is by no means an unlikely occurrence. Even when the amputation is performed pretty far up the limb, the corners of the stump frequently mortify, or become livid; but a few doses of bark and wine stop the progress of the disease. Although it is a general rule that amputation is necessary whenever the member is so destroyed as to become useless, and although this must not be performed until the ulcerative action be induced, yet it must not invariably be performed whenever this action takes place, because sometimes at this period the patient is unable to sustain the general action which the operation would produce. We must, therefore, if the patient be much reduced by the extent, or long continuance of the disease, rather delay until, by good diet, wine, &c. we have procured an increase of strength; but, if we find that either the patient loses ground, or his weakness remains stationary under this treatment, we must then amputate; because, it is probable, that the continuance of the dead portion in contact with the living is tending to induce still the general action of descent[73].