Preparation. - (Unoff.): Syrupus Calcii Iodidi, 3.4 p. c. - iodine 7.6, iron wire 2.8, sugar 70, dist. water q. s. 100, dose, 3ss-l (2-4 Ml. (Cc.)).

Properties and Uses. - Similar to Creta Prseparata, page 738.

Calcii Glycerophosphas. Calcium Glycerophosphate, C3H5(OH)2-CaPO4 + H2O. - (Syn., Calc. Glycerophos., Calcium glycerino-phospho-ricum; Fr. Glycerino-phosphate de Chaux; Ger. Calcium glycerino-phosphat.)

Manufacture: Neutralize solution of glycerophosphoric acid with milk of lime or calcium carbonate, filter off calcium phosphate, concentrate filtrate in vacuum, precipitate with alcohol. It is a fine white powder, odorless, almost tasteless, somewhat hygroscopic, soluble in water (50), more soluble in cold water and in the presence of citric acid, insoluble in alcohol; saturated aqueous solution alkaline; this normal form contains 98 p. c. of the salt. Tests: 1. Cold, saturated aqueous solution heated to boiling - white, iridescent scales (anhydrous calcium glycerophosphate); decomposes at 170° C. (338° F.), evolving inflammable vapors, at red heat converted into calcium pyrophosphate. 2. Saturated aqueous solution + ammonium oxalate T. S. - white precipitate, insoluble in acetic acid, soluble in hydrochloric acid; + lead acetate T. S. - white curdy precipitate, insoluble in nitric acid. Impurities: Heavy metals, chloride, phosphates, sulphate, water, alcohol-soluble substances. Should be kept in well-closed containers. Dose, gr. 5-10 (.3-.6 Gm.), in powder, water, capsule, tablet, suspended in water or syrup, or dissolved in little citric or diluted hydrochloric acid, or wine. 47

Preparation. - (Unoff.): Elixir Calcii et Sodii Glycerophosphatum, .875 p. c, + solution of sodium glycerophosphate 2.5, phosphoric acid .8, +, dose, 3j-2 (4-8 Ml. (Cc.)).

Properties and Uses. - Nervine, tonic, where calcium and phosphate are required; phosphorus of lecithin of food is converted into glycerophosphoric acid before assimilation - the most natural form for administering phosphorus. Rachitis, neurasthenia, scrofula, difficult dentition, wasting diseases, convalescence, sciatica, incontinence of urine, diabetes.

Creta Praeparata. Prepared Chalk, CaCO3. - (Syn., Cret. Prsep., Drop Chalk, Creta Laevigata; Fr. Craie preparee, Craie Lavee; Ger. Praparirte Kreide, Schlammkreide.)

Manufacture: Chalk is a very abundant mineral, occurring largely on the coast of the English Channel and consisting of infinitesimal shells of foraminifera composed mostly of calcium carbonate, but having more or less silica, aluminum, iron, magnesium, and organic matter. Our official prepared chalk is this native friable CaCO3, freed from most of these impurities by elutriation, which consists in washing finely powdered chalk or whiting (the latter being the deposit from the first washings of water) with cold water, allowing the coarser particles to subside, decanting the milky liquid on suitable straining cloths, collecting the moist residue and forming same into small nodules by dropping soft mass from a funnel-shaped vessel onto a drying-tray, or may be molded into crayon-sticks, and in either shape left white or tinted with various coloring substances. It is a white, grayish-white, very fine, amorphous powder, conical drops, odorless, tasteless, permanent, almost insoluble in water, alcohol, decomposed and dissolved by diluted acetic, hydrochloric, or nitric acid, with copious effervescence; dissolved in diluted hydrochloric acid - residue not more than 2 p. c.; contains 97 p. c. of the salt. Tests: 1. Dissolve .1 Gm. in diluted acetic acid 5 Ml. (Cc), add to filtrate ammonium oxalate T. S. - white precipitate, insoluble in acetic acid, soluble in hydrochloric acid. 2. Heat to redness - loses gradually carbon dioxide, yielding calcium oxide; gypsum sometimes sold for it.

Preparations. - 1. Pulvis Cretae Compositus. Compound Chalk Powder. (Syn., Pulv. Cret. Co.; Fr. Poudre de Craie composee; Ger. Kreidepulver mit Gummi.)

Manufacture: Mix thoroughly prepared chalk 30 Gm., acacia 20 Gm., sugar 50 Gm. Dose, gr. 5-60 (.3-4 Gm.).

Prep.: 1. Mistura Cretae. Chalk Mixture. (Syn., Mist. Cret.;

Fr. Mixture avec la Craie; Ger. Kreidemixtur.) Manufacture: Gradually add cinnamon water 40 Ml. (Cc), water 20 Ml. (Cc.) to compound chalk powder 20 Gm. in a mortar, triturate until uniform, transfer to graduated vessel, rinse mortar with water q. s. 100 Ml. (Cc), mix thoroughly. Must not be dispensed unless recently prepared. Dose, 3 j-4 (4-15 Ml. (Cc)).

2. Hydrargyrum cum Creta, 57 p. c, + mercury 38 p. c

Unoff. Preps.: Troches, 3 3/4 gr. (.24 Gm.). Pulvis Cretae Aromaticus, 25 Gm., + Saigon cinnamon 8, myristica 6, clove 3, cardamom seed 2, sugar 56, dose, gr. 15-60 (1-4 Gm.). Pulvis Cretae et Opii Aromaticus - arom. powder of chalk 97.5, opium 2.5, dose, gr. 10-60 (.6 1 Gm.).

Properties and Uses. - Mainly in tooth powders, etc.; the precipitated is considered best for such preparations, as it is finer and contains no grit; the prepared is preferable for chalk mixtures, face and toilet powders, from its more adhesive properties, dusting powder to ulcers, burns, abrasions; antidote to oxalic acid poisoning; the troches used as a mild astringent, antacid in diarrhoea, gastric acidity (preceded by a purge), being well adapted for children; the mixture for diarrhoea, loose bowels of infants, etc.

Incompatibles: Acids and sulphates.

Calcii Bromidum. Calcium Bromide, CaBr2. - (Syn., Calc. Brom.; Fr. Bromurede (Chaux) Calcium; Ger. Bromcalcium, Calcium (bromid) bromatum.)

Manufacture: Dissolve pure calcium carbonate in hydrobromic acid, filter, evaporate to dryness - CaCO3 + 2HBr = CaBr2 + H2O + CO2; or by boiling milk of lime with ammonium bromide. It is a white granular salt, odorless, sharp, saline taste, very deliquescent, soluble in water (.7), boiling water (.4), alcohol (1.3), insoluble in chloroform, ether; aqueous solution (1 in 20) neutral, slightly alkaline; this hydrated form contains 84 p. c. of the salt. Tests: 1. Aqueous solution (1 in 20) + ammonium oxalate T. S. - white precipitate, insoluble in acetic acid, soluble in hydrochloric acid. 2. Aqueous solution (1 in 10) + silver nitrate T. S. - yellowish-white precipitate, insoluble in nitric acid or excess of ammonia water. Impurities: Heavy metals, iron, alkalies, barium, magnesium, bromate, chlorides, iodide, sulphate. Should be kept in well-closed containers. Dose, gr. 10-30 (.6-2 Gm.), in water.