is made, when there may be detected a little roughness on some part of one of those teeth, and the mystery is explained. There may be no, or a very slight increased growth of the molar, which, in the opposing jaw, corresponds to that which is evidently carious. The carious tooth may be firmly implanted; and yet, notwithstanding the firm manner in which it is fixed in the jaw, no time ought to be lost in its removal. The operation may occupy some time, and should be conducted with proper caution if the horse be young; and I have by me a molar taken from the jaw of a colt that was rising four, in which the crusta petrosa was diseased. A wood-cut representing that tooth, is inserted at page 29; and the darker spot indicates the place where decay had commenced. During youth the fangs of the molars are of great length, consequently, any violence would be likely to do injury to the thin plates of the alveolar cavity. In old animals the fangs being shorter, greater speed may be allowable; but in every instance where the tooth is firm, judgment must be exercised. Supposing the horse to be young, the following method will be found to answer:--The precise position of the tooth having been ascertained, and the animal cast, traction, with a proper instrument, is made in the right direction. In the first attempt the force is not designed to extract the tooth; if it can be perceptibly moved or raised upward, so that the nerves and arteries of the pulp may be broken or ruptured, a great point has been gained, and the molar should be no further drawn in the first instance. The instrument should be then loosened, and another hold having been taken, a renewed effort should be made, when a little additional way may be gained. After this, a further hold should be taken, and thus adapting the grasp of the instrument to each pull, and proceeding gradually, the molar may be extracted. The operator, however, must not, in every instance, anticipate that he will be thus successful. The tooth may be perceptibly moved, but after this it may resist all subsequent attempts. The surgeon will become aware that only great force could accomplish his wishes, and he will therefore reflect whether the employment of the necessary violence might not fracture the jaw as well as extract the tooth. Something has been gained by rupturing the arteries and nerves. The pain and course of the disease has, in a degree, been checked. The molar is no longer a part of the body, but a foreign substance; and Nature, if left alone, will proceed in her own way to eject it. The course, however, that Nature, if unaided, would pursue, might be too slow to prevent evil consequences. The operator, therefore, discontinues his attempts for the present; and though some foolish persons will think slightly of him, for not at once doing the thing he desired to accomplish, he orders the animal to be let up, and led back into the stable. Many a proprietor has been so displeased by this, that he has