The _prognosis_ is always grave in the extreme, the main risks being general toxæmia and septic pneumonia. When recovery takes place there is serious deformity, and considerable portions of the jaws may be lost by necrosis. [Illustration: FIG. 23.--Cancrum oris. (From a photograph lent by Sir George T. Beatson.)] _Treatment._--The only satisfactory treatment is thorough removal under an anæsthetic of all the sloughy tissue, with the surrounding zone in which the organisms are active. This is most efficiently accomplished by the knife or scissors, cutting until the tissue bleeds freely, after which the raw surface is painted with undiluted carbolic acid and dressed with iodoform gauze. It may be necessary to remove large pieces of bone when the necrotic process has implicated the jaws. The mouth must be constantly sprayed with peroxide of hydrogen, and washed out with a disinfectant and deodorant lotion, such as Condy's fluid. The patient's general condition calls for free stimulation. The deformity resulting from these necessarily heroic measures is not so great as might be expected, and can be further diminished by plastic operations, which should be undertaken before cicatricial contraction has occurred. BED-SORES Bed-sores are most frequently met with in old and debilitated patients, or in those whose tissues are devitalised by acute or chronic diseases associated with stagnation of blood in the peripheral veins. Any interference with the nerve-supply of the skin, whether from injury or disease of the central nervous system or of the peripheral nerves, strongly predisposes to the formation of bed-sores. Prolonged and excessive pressure over a bony prominence, especially if the parts be moist with skin secretions, urine, or wound discharges, determines the formation of a sore. Excoriations, which may develop into true bed-sores, sometimes form where two skin surfaces remain constantly apposed, as in the region of the scrotum or labium, under pendulous mammæ, or between fingers or toes confined in a splint. [Illustration: FIG. 24.--Acute Bed-Sores over Right Buttock.] _Clinical Features._--Two clinical varieties are met with--the acute and the chronic bed-sore. The _acute_ bed-sore usually occurs over the sacrum or buttock. It develops rapidly after spinal injuries and in the course of certain brain diseases. The part affected becomes red and congested, while the surrounding parts are œdematous and swollen, blisters form, and the skin loses its vitality (Fig. 24). In advanced cases of general paralysis of the insane, a peculiar form of acute bed-sore beginning as a blister, and passing on to the formation of a black, dry eschar, which slowly separates, occurs on such parts as the medial side of the knee, the angle of the scapula, and the heel.