Uses, &c. It is chiefly employed for making aromatic confection, cretaceous powder, and chalk mixture. That of the shops is seldom pure, the refuse of the soda-water makers (sulphate of lime) being commonly sold for it. When pure it is wholly soluble, with effervescence, in dilute hydrochloric acid. (See below.)
Chalk, Prepa′′red. Syn. Cre′ta (Ph. E. & Ph. L. 1836), Cre′ta prepara′ta (Ph. L. 1851), Cre′ta al′ba (Ph. D.), L. Prep. 1. (Ph. D. 1836.) Rub chalk, 1 lb., with sufficient water, add gradually, until reduced to a smooth cream; then stir this into a large quantity of water, and, after a short interval, to allow the coarser particles to subside, pour off the supernatant water (still turbid) into another vessel, and allow the suspended powder to settle; lastly, collect the chalk so prepared and dry it. In the same way shells are prepared, after being first freed from impurities and washed with boiling water.
2. (Commercial; Whi′ting.) On the large scale the chalk is ground in mills, and the elutriation and deposit made in large reservoirs. It is now seldom prepared by the druggist.
Pur. Almost entirely soluble in dilute hydrochloric acid, provided it contains no sulphate
of lime or silica, giving off small bubbles of carbonic acid gas.
Test. The salt formed by dissolving the chalk in hydrochloric acid, if rendered neutral by evaporation to dryness and redissolved in water, gives only a very scanty precipitate on the addition of a saccharated solution of lime, indicating absence of phosphate. (B. P.)
Uses, &c. In medicine, as an absorbent, antacid, and desiccant; in acidity, heartburn, dyspepsia, and other like stomach affections, and in diarrhœa, depending on acidity or irritation; in the latter, generally combined with aromatics, astringents, or opium. It forms a valuable dusting powder in excoriations, ulcers, &c., especially in those of children.—Dose, 10 gr. to a spoonful, in a little water or milk, or made into a mixture with mucilage or syrup.
Chalk, Red. A natural clay containing about 18% of protoxide and carbonate of iron.
CHALYB′EATES. Syn. Chalybea′ta, Ferrugin′ea, L. The medicinal qualities of the preparations of iron are noticed under the name of that metal. Those most frequently employed in medicine are—IRON FILINGS; Quevenne’s iron; the BLACK OXIDE, MAGNETIC OXIDE, and SESQUIOXIDE OF IRON; the AMMONIO-CHLORIDE and SESQUICHLORIDE; the CARBONATE and SACCHARINE CARBONATE; the CITRATE and AMMONIO-CITRATE; the IODIDE, LACTATE, and SULPHATE; the TARTRATE, AMMONIO-TARTRATE, and POTASSIO-TARTRATE OF IRON; and the CHALYBEATE MINERAL WATERS. For the doses, &c., see the respective articles.
CHAM′OMILE. Syn. Anthe′mis, L. The flowers of the Anthemis nobilis (Anthemidis Flores, B. P.). They are bitter, stomachic, and tonic; in dyspepsia, loss of appetite, intermittents, &c. They are an effectual remedy for nightmare; and, according to Dr Schall, the only certain remedy for that complaint.—Dose, 10 gr. to 1⁄2 dr., or more, in powder or made into a tea. Fomentations are also made with it. See Extracts, Oils, Pills, &c.