TARTAR.--If there is a tendency to the formation of tartar, then it will be necessary to have recourse to some tooth-powder. Tooth-powders, however, must be chosen with care, as many of them are composed of substances highly injurious to the teeth. "Many of the tooth-powders which are offered for sale, with the promise of rendering the teeth beautifully white, perform, for a time, all that is promised, at the expense of permanent and irremediable injury to the teeth; for they often contain a quantity of tartaric or other acid, which effects a gradual decomposition of the enamel."[FN#25] Prepared chalk is one of the simplest and best tooth-powders. [FN#25] Bell on the Teeth. The following form, also, may be used with advantage:-- Prepared chalk, three ounces; Orris root, powdered, half an ounce; Powdered myrrh, half an ounce; Cuttle fish, powdered, one ounce; Essential oil of cinnamon, four drops.--Mix. The best preservative, then, against the formation of tartar, is to see that the child cleans his teeth thoroughly night and morning with the brush, powder, and water, and also (if possible) that he rinses out the mouth after each meal. If the gums should be tender, irritable, and bleed (as is frequently the case when an individual gets out of health, or the tartar accumulates) the mouth may be washed night and morning with a tumbler of tepid water, containing from ten to twenty drops of the tincture of myrrh, and the same quantity of spirits of camphor; or the following form may be used:-- Alum, one drachm and a half; Tincture of myrrh, two drachms; Camphor mixture, five ounces and a half.--Mix. ACIDS.--The use of acids to the teeth cannot be too strongly deprecated: they decompose their substance, and lead to their rapid decay. Hence the whiteness produced by acid tooth-powders and washes is not less deceitful than ruinous in its consequences. As has been just observed, they perform all that their vendors promise, causing the teeth, for a little while, to become very white and beautiful in their appearance, but, at the same time, injuring them irremediably: the enamel becomes gradually decomposed, the bone of the tooth exposed, and its death is the inevitable consequence. It is therefore of great importance when acid medicines are ordered for children that they should be taken through a glass tube, to prevent their coming in contact with the teeth. From a want of this precaution, I know a lady (and there are many such instances) who once had as sound and fine a set of teeth as any one could boast of, but from this cause has had nearly the whole of the upper row destroyed. She was in delicate health: it was judged requisite that she should take for a considerable time (with other medicines) sulphuric acid; but the glass tube was not thought of, and the consequences followed which have been described.