Chalk, Brown. A familiar name for umber.
Chalk, Cam′phorated. Syn. Cretaceous tooth powder, Cam′phorated t. p.; Cre′ta cam′phorata, C. cum campho′ra, L. Prep. 1. Camphor, 1 oz.; add a few drops of spirit of wine, reduce it to a very fine powder, and mix it (perfectly) with precipitated chalk, 7 oz.; lastly, pass it through a clean, fine sieve, and keep it in a corked bottle. These proportions make the strongest “CAMPHORATED TOOTH POWDER” of the shops.
2. Camphor, 1 oz.; precipitated chalk, 15 oz.; as before. These are the best and safest proportions, and those now generally adopted by the West-end perfumers.
3. As either of the above, but using prepared chalk in lieu of precipitated chalk. Less white and velvety, but cleans the teeth better than the softer article.
Uses, &c. Camphorated chalk is much esteemed as a dentifrice; especially by smokers, and those troubled with foul teeth, or offensive breath. It may be scented with a few drops (3 or 4 to each oz.) of otto of roses, oil of cloves, or neroli, or of the essences of ambergris, musk, or vanilla; but care must be taken not to overdo it. When the teeth are much furred or discoloured, it may be mixed with about one seventh of its weight of finely powdered pumice stone (sifted through lawn), which will render it more effective. A little carmine, rouge, light red (burnt ochre), red coral, or rose pink, is also sometimes added to give it a tinge approaching that of the gums. The quantity of camphor (1 to 3 or 4) commonly ordered in certain books is absurdly large, and would render the compound not only unpleasant in use, but actually detrimental to the teeth. See Dentifrices.
Chalk, French. Soap stone or steatite, a soft magnesian mineral, possessing the property of writing on glass. It is used by tailors for marking cloths. Its powder (obtained by scraping) is very soft, velvety, and absorbent of grease. It forms the boot powder of the boot- and shoe-makers.
Chalk Mixture. Syn. Mistura Cretæ, L. Prepared chalk, 1 part; gum arabic (in powder), 1 part; syrup, 2 parts; cinnamon water, 30 parts; mix by trituration.—Dose, 1 to 2 oz., with astringent tinctures and opium. Care should be taken to use the prepared chalk as directed; the precipitated chalk has a crystalline character, and is said to occasion irritation of the bowels. (Squire.)
Chalk, Precip′itated. Syn. Precipitated car′bonate of lime; Cre′ta præcipita′ta, Cal′cis carb′onas præcipita′tum, L. Prep. 1. By adding to a solution of chloride of calcium, any quantity, another of carbonate of soda (both cold), and well washing the precipitate with pure water, and drying it out of the dust.
2. (Ph. D.) Solution of chloride of calcium (Ph. D.), 5 parts; carbonate of soda, 3 parts; (dissolved in) water, 4 parts.
3. (B. P.) Dissolve chloride of calcium, 5 oz.; and carbonate of soda, 13 oz.; each in two pints of boiling distilled water; mix the two solutions, and allow the precipitate to subside. Collect this on a calico filter, wash it with boiling distilled water, until the washing cease to give a precipitate with nitrate of silver, and try the product at the temperature of 212° F.