It is a corroding ulcer, without hardness of the surrounding parts, presenting no appearance of regeneration of the tissues which have been destroyed. It may follow either upon a pustule or an abrasion. Sometimes it destroys the prepuce and glans in a few days, or again, when chronic, it spreads deceitfully, healing at one part and destroying at another. The ulceration is often deep, penetrating the corpora cavernosa, or the corpus spongiosum urethræ: in such cases it is followed with violent hemorrhage, which often produces a great and sudden improvement in the sore. After slow cicatrisation it not unfrequently happens that the scar gives way, and the ulceration returns. Sometimes another character is given to the sore, by the rapid sloughing of the parts. In this modification, a small black spot is first observable, unattended with pain: it enlarges rapidly, and, after no long time, the mortified part separates, exposing an unhealthy surface, which is immediately attacked and progressively destroyed by phagedena. The part may again slough, and, by an alternation of mortification and phagedenic ulceration, the external organs of generation, male or female, may be wholly destroyed. In the present day, however, its ravages are much less extensive and more easily combated than formerly, and it seldom, if ever, proves fatal. One very troublesome case is in my recollection, where the patient suffered two attacks at the interval of two years. During the progress of the disease he was seized with delirium tremens; a bubo formed and ulcerated; a violent hemorrhage occurred from the sore; sloughing and phagedena alternated; and both prepuce and glans were entirely lost. An eruption followed, accompanied with ulceration of the throat and nostrils. He recovered much mutilated. Ulcers originally of a simple character may become affected with phagedena, or sloughing, from the state of the constitution, from mismanagement, or from exposure to an unhealthful atmosphere. But in such cases, after the separation of the slough, the exposed surface is found to be of a healthy granulating character, contrary to what is observed in the originally phagedenic disease. Buboes, when they occur, have the same malignant action as the primary sore: the breach of surface is extended either by sloughing or by phagedenic ulceration, and the edges of the sore are ragged and undermined.