The ulcerated state of the mouth is usually connected with special disorder of the digestive organs, and that condition of acidity for which I have already recommended soda, magnesia, and similar remedies, while locally the mouth needs just that local care which is applicable in cases of thrush. Now and then, severe inflammation of the gums occurs, in which they become extremely swollen; and ulceration takes place of the gum just above where the tooth should come through, and even around some of those which have already appeared. These are cases in which lancing the gums would do nothing but mischief. They require the local care already insisted on, a mild plan of diet, and treatment to reduce any feverishness; and above all one medicine, the chlorate of potass, which in doses of four grains every four hours for a child a year old, is almost a specific. AFFECTIONS OF THE SKIN.--There are a few affections of the skin to which children in early infancy are especially liable, concerning which a few words must be said. The Latin word _intertrigo_ is used for that _chafing_ of the skin of the lower part of the body of an infant which is by no means unusual, and is often very distressing. It is almost invariably due to want of care. Either wetted napkins are dried, and put on again without previous rinsing in water, or they have been washed in water containing soda, and not passed through pure water afterwards, or attention is not paid to change the infant's napkin immediately that it requires; or a fresh napkin is put on without previous careful ablution of the child; or lastly it occurs almost unavoidably in cases of diarrh[oe]a from the extension of irritation beginning at the edge of the bowel. Care is usually all that is needed to remove, as it is to prevent this condition. The precautions which I have referred to with regard to cleanliness must be carefully observed, and moreover, each time even after passing water, the child should be carefully washed with thin gruel, or barley water, then dusted abundantly with starch powder, while the napkin must be thickly greased with zinc ointment. After the first six or seven months of life the napkin can be almost always dispensed with, if the child has been brought up in good habits, and in all cases of chafing, it is much the better way to put no napkin on the child when in bed, but to lay under it a folded towel, which can be removed, and a clean one substituted for it as soon as it becomes soiled. There is a very obstinate form of chafing, with great redness of the skin, and disposition to crack about the edge of the bowel which depends on constitutional causes, and calls at once for the interference of the doctor.