In Small-pox, besides the general catarrh of the mouth already mentioned, there are vesicles or pustules analogous to those on the skin. We have first whitish patches consisting of raised and desquamating epithelium. The epithelium is soon discharged and superficial ulcers result. In Scurvy there is great swelling and oedema of the mucous membrane of the gums around the teeth. The gums bleed, and, apparently as a consequence of this, ulcers form around the teeth and may extend down to the bone, which may undergo necrosis. Very often the teeth are loosened. As a consequence of the use of mercury we sometimes have a considerable stomatitis. It occurs after the medicinal use of mercury and also among workmen who make use of it in their occupations. The mucous membrane is swollen, especially that of the gums and cheeks, and there is severe salivation. Ulcers frequently form, especially on the internal surface of the cheeks and lips, and on the edges of the tongue. They may be in the form of flat excoriations or deeper ulcers with a membranous covering.