put nitrate of silver upon the whole of the ulcer, and increased the mischief. I simply desired that the ulcer should be left at rest; that the patient, to avoid touching the tooth, should neither talk nor move his tongue more than necessary; that he should wash his mouth with some poppy fermentation, and take a little soda and sarsaparilla twice a day. In three days about one-third of the ulcer was healed up, actually cicatrized, the enlarged gland nearly gone, and the earache much diminished. “This rapid improvement might appear something like exaggeration, but all surgeons know that the tongue has those elements within it which contribute to the most rapid repair of injury. I do not know any tissue that repairs itself more rapidly. It is abundantly supplied with capillaries filled with arterial blood, and has an enormous distribution of nerves, and these are two elements that contribute to rapid reparation. It was quite clear that the treatment was in the right direction, viz., that of giving rest to the tongue and ulcer. After a few more days I requested him to consult a dental surgeon with respect to the propriety of taking off the points of the tooth. This was afterwards done, and the patient soon lost his anxiety about cancer, his earache, and all his other severe symptoms.” I cannot doubt that the starting point of a large number of similar painful ulcers and of true cancer of the mouth is to be looked for in disease of the teeth. When we come to the teeth themselves, the pain lies in the irritated nerves of the pulp. Of course it cannot be denied that the pulp itself may be the original seat of the pain, but, if so, the number of such cases must be few. When we reflect on the mode of nutrition of the tooth, it seems almost self-evident that any depressing agency which could lead to disease of the pulp must, by an augmented action, cause greater disease in the structures which depend on the pulp for their nutrition to start with. At most, disease and pain in the pulp alone must be nothing less than a pathological curiosity. Such, however, is not the case in the vast multitude of cases dependent on caries, in which the pulp has lost in part or in whole its protection from external morbid influences. The origin of caries is one of the most interesting subjects in the whole domain of surgery. I have been astonished to find that among dentists it is not more definitely settled. So able a writer as Wm. Henry Potter (of Harvard) says: “In the first place, it may be said that caries of the teeth does not resemble caries of the bone. The term caries, as applied to the teeth, is a misnomer, given at a time when the true nature of the process was not understood.... The pathological change which occurs in caries is a decalcification and disintegration of the several tissues of the teeth.”