_Dry_ or _senile gangrene_ presents a very distinct contrast to the moist type. It occurs generally in patients over fifty, often as the result of causes which are slow of action. As a result of the shrinking and corrugation of the tissues, with the dryness of the same by evaporation, there is a peculiar appearance known as _mummification_, the foot, for instance--the feet are usually first involved--resembling the foot of a person who has been embalmed, except that it is discolored. It is possible sometimes to have a combination of moist and senile gangrene, especially when there has been infection by which putrefaction is permitted. When from the outset putrefactive processes are prevented, the gangrene of this type is almost invariably dry. In practically all of the cases of this character there will be found evidences of vascular disease, usually in the femoral artery and its branches. Gangrene of the foot alone is most commonly due to endarteritis, while gangrene of the foot and leg together are usually due to embolism or thrombosis. While disease of the vessel walls is usually of the type either of endarteritis or arterial sclerosis, peculiar to the closing years of life, and commonly affecting the lower extremities, gangrene due to embolism of arteries or thrombosis, or both, may occur in the young, and in the upper extremities as well, in the latter case the emboli being detached from the heart, while thrombosis may be caused by a tight splint or bandage, or even the use of crutches. I have repeatedly amputated the arm as well as the leg for gangrene of this type. =Signs and Symptoms.=--The appearance and the odor of a part will indicate impending or actual traumatic gangrene. The pallor, the coldness, the dryness of senile gangrene are also characteristic. In the latter form constitutional symptoms are not indicative nor essentially of septic type. As soon, however, as a process of spontaneous separation begins putrefaction is inevitable and sepsis unavoidable. In moist gangrene there is seldom acute pain. This is one of the predominating subjective features of the senile form. Hemorrhages occur, sometimes terminating fatally, in the moist forms when large vessels are eroded. This is particularly true of the _phagedenic_ or _hospital_ form. A recognition of their possibility may enable us to avoid sudden death from this source.