Take an old silver thimble, an old silver coin, or other silver article, and with a very fine file, convert it into filings. Sift through gauze, to separate the coarse from the fine particles. Take the finer portion, and mix with sufficient quicksilver to form a stiff amalgam, and while in this state, fill the cavities of decayed teeth. This is precisely the same as the metallic amalgam used by all dentists. Quicksilver may be bought at a trifle per half-ounce or ounce, at the chemist's. We have not the slightest hesitation in pronouncing this to be the best thing of the kind. Caution: as it turns black under the action of the acids of the mouth, it should be used sparingly for front teeth. A tooth should never be filled while it is aching. (See 144.)