Tooth Powders; Dentifrices ; Poudres pour les Dents; etc.. These preparations should be compounded of materials which, while cleaning the teeth without injury to the enamel, will also be anti-acid, anti-scorbutic, and tonic in their action upon the gums. Cooley says : " Great care should be taken to finely pulverize all the dry ingredients, and to reduce the harder and gritty ones to the state of impalpable powder, either by patient levi-gation or trituration, or by elutriation. (See Nos. 25 (Pulverization), 31, and 14.) To ensure the perfect mixture of the ingredients, they should be stirred together until they form an apparently homogeneous powder, which should then be passed or rubbed through a fine gauze-sieve. Those which contain volatile or perishable substances, or which, like charcoal, are affected by contact with the air, should be put up in dumpy, wide-mouthed bottles, and kept closely corked." "Tooth powders are nearly all compound powders. The only simple powder in common use as a dentifrice is powdered charcoal. Powdered bicarbonate of soda, cream of tartar, etc., are also employed, though less frequently." The following list includes some of the best tooth-powders in common use, as well as several advertised nostrums and named powders of the stores. By omitting the honey and spirit, the formula) given for tooth pastes furnish others for tooth powders; and vice versa. Thus, the example given under each will increase the number of the other; and both will suggest to the reader other formula.

1289. Poudre D'etersive Dentifrice

1289.     Poudre D'etersive Dentifrice. "Willow charcoal and white sugar in impalpable powder, each 8 ounces; calasaya bark in impalpable powder, 4 ounces; mix thoroughly in a mortar, sift through the finest bolting cloth, and perfume with a mixture of attar of mint, 2 drachms; attar of cinnamon, 1 ounce; and tincture of amber, 1/2 ounce.

1290. Camphorated Chalk

1290.    Camphorated Chalk. Precipitated carbonate of lime (chalk), 1 pound; powdered orris root, 31/2 pounds; powdered camphor, 1/4 pound; reduce the camphor to fine powder by triturating it in a mortar with a little alcohol; then add the other ingredients, and when the mixture is complete, sift through the finest bolting cloth. (See No. 28 (Sifting).)

1291. Precipitated Chalk

1291.     Precipitated Chalk. This is prepared by adding a solution of carbonate of soda to a solution of chloride of calcium (both cold), as long as a precipitate forms. This last is well washed with pure water, and dried out of the dust, as the last. The refuse sulphate of lime of the soda-water makers, which is poisonous in quantity, is often sold for it by the druggists. Pure chalk is wholly soluble in vinegar, and in dilute acetic, hydrochloric, and nitric acid, with effervescence. Sulphate of lime is insoluble in these fluids.

1292. To make Prepared Chalk

1292.      To make Prepared Chalk. Rub 1 pound chalk with sufficient water, added gradually, to make it a smooth cream; then stir this into a large quantity of water, after the coarser particles have settled decant the milky fluid into another vessel, and allow the chalk to settle; decant the clear water, and dry the sediment.