=Ulcerous Form.=--This does not occur in children under five, but may attack persons of all greater ages. It is often seen following measles and scarlet fever, and in the poor and ill nourished, and after the unwise use of calomel. There are redness and swelling of the gum about the base of the lower front teeth, and the gums bleed easily. Matter, or pus, forms between the teeth and the gum, and the mouth has a foul odor. The gum on the whole lower jaw may become inflamed, and a yellow band of ulceration may appear along the gums. The glands under the jaw and in the neck are enlarged, feeling like tender lumps, and saliva flows freely. In severe cases the gums may become destroyed and eaten away by the ulceration, and the bone of the jaw be diseased and exposed. As in the graver cases it may become necessary to remove dead bone and teeth, and the very dangerous form next described may sometimes follow it, it will be seen that it is a disease requiring skilled medical attention. The treatment consists in using, as a mouth wash and gargle, a solution of chlorate of potash (fifteen grains to the ounce) every two hours. Cases usually last at least a week. =Gangrenous Form.=--This is a rare and fatal form of inflammation of the mouth and occurs in children weak and debilitated from other diseases, as from the contagious eruptive fevers, chronic diarrhea, and scurvy. It is seen more often in hospitals and is contagious. A foul odor is noticed about the mouth, in which will be seen an ulcer on the gum or inside of the cheek. The cheek swells tremendously, with or without pain, and becomes variously discolored--red, purple, black. The larger proportion of patients die of exhaustion and blood poisoning within one to three weeks, and the only hope is through surgical interference at the earliest possible moment. =CANKER.=--A small, shallow, yellow ulcer, appearing on the inside of the lips or beneath the tongue during some disorder of the digestion. It is very tender when touched and renders chewing or talking somewhat painful. Treatment consists of touching the ulcer carefully with the point of a wooden toothpick which has been dipped in pure carbolic acid (a poison) and then rinsing the resulting white spot and the whole mouth very carefully, so as not to swallow any of the acid. Inflammation of the mouth occurs in two other general diseases, in syphilis and rarely in diphtheria. In children born of syphilitic parents, deep cracks often appear at either side of the mouth and do not heal as readily as ordinary sores, but continue a long time, and eventually leave deep scars. In diphtheria the membrane which covers the tonsils sometimes spreads to the cheeks, tongue, and lips, but in either case the general symptoms will serve to distinguish the diseases, and neither can be treated by the layman.