A gentleman, a physician, aged thirty-two years, strong and vigorous, with no lack of nerve-energy, calls to have his teeth attended to, with the disease in the first stage throughout the mouth. Upon examination, he observes upon the gum of one of the lower cuspids a dark purplish ring encircling the neck, from one-sixty-fourth to one sixteenth of an inch in depth; the tooth _in situ_ is white and clean. With the aid of the mouth and hand mirror he shows the condition to the patient, and, taking up an excavator, endeavors to pass it down between the tooth and gum, on the labial surface. After it gets down a little way the instrument meets with an obstruction, over which, calling the patient's attention to the fact, he carefully guides the instrument until it drops down on the tooth-substance beyond it; then, turning the instrument and pressing it upward, he breaks off a portion of the concretion; which proves to be what is ordinarily called lime-salts, or tartar. That is the cause of the purple ring on the gum, which is merely the outward manifestation of the disease. Take it off thoroughly, polish the surface of the tooth, and in three days' time the gum will show a perfectly healthy color. The condition described is the first stage of the disease, and the treatment given is all that is required for a cure of the case at this time. But take the same man and let him go for ten years without the simple operation detailed. The disease spreads, and causes inflammation of the process, and, finally, its absorption--sometimes on the labial surface for one half or two-thirds the length of the tooth. It runs its course, the tartar accumulating, all the time following up the line of attack. At the end of ten years what has become of the line of tartar? Sometimes it will be found extending clear around the tooth. Sometimes it will not be found at all; it has done its work--the tooth is loose, but the concretion is gone, in whole or in part. In this case the patient wants the tooth out, but, he asks, what has become of the tartar? The answer is that the natural acids found in the oral cavity have dissolved it, and it has passed into the stomach or out of the mouth in the saliva. But the tooth is so loose that it is a torment to the man; it lies in its socket, entirely loose, almost ready to drop over. It hurts so that he cannot bear the pain. The tooth is taken out. There is no tartar on it, or very little; there is a little speck near the point that looks like a foreign body; but the point of the tooth--the apex--is as sharp as a needle. After the disease has done its work of separating the tooth from its socket, the destroying agent begins to absorb the tooth at the point, irregularly, causing the sharpness described. Now, because no tartar is found upon the tooth, does that argue that it has never been there? Not at all; the loosened tooth shows simply that it has been there and has been absorbed.