The element calcium (L. calx, calcis, limestone, Gr.

Calcium Caii 40 900

is one of a group of three - calcium, barium, strontium - which form the alkaline earths. These metals, like the alkalies and magnesium, decompose water, liberating hydrogen; metallic calcium is light, yellow, ductile like gold, malleable; seldom met with except as the native salts, which are very abundant. The carbonate occurs in calc-spar, chalk, limestone, marble, shells of eggs, mollusca, etc.; acid carbonate in water; sulphate in alabaster, gypsum, bones; phosphate in apatite, animal bone, etc.; fluoride in fluorspar; chloride in water; silicate in rocks of various kinds.

Tests for Calcium Salts: 1. With soluble salts the alkaline carbonates give white precipitates, insoluble in excess. 2. With ammonium or potassium oxalate we get a white precipitate, insoluble in acetic but soluble in hydrochloric acid. 3. With sulphuric acid or KOH or NaOH get white precipitates in strong calcium solutions, but not in diluted solutions. 4. Give reddish-yellow color to flame.

Calx. Calcium Oxide, CaO. - (Syn., Lime, Quicklime, Burned Lime, Calcaria, Calx Viva, Calx Usta, Oxydum Calcicum, Calcium Oxide; Fr. Chaux (vive); Ger. Calcaria usta, Gebrannter Kalk,

Atzkalk, Kalk.)

Manufacture: By calcining white marble or the purest varieties of native calcium carbonate - CaCO3 + heat = CaO + CO2. It is in hard, white, grayish-white masses, granules, or white powder, odorless, caustic taste, soluble in water (840), boiling water (1740), glycerin, syrup, insoluble in alcohol; moistened with water becomes heated and gradually converted into a white powder (calcium hydroxide, slaked lime), which mixed with water (3-4) forms smooth magma (milk of lime); agitated with water alkaline; contains 95 p. c. of the salt, and on ignition loses not more than 10 p. c. Tests: 1. Mix 5 Gm., after slaking, with distilled water 100 Ml. (Cc), + few drops of hydrochloric acid, agitate until dissolved, boil, cool - should be acid, and not more than .05 Gm. of insoluble matter should deposit. 2. Neutralize a portion of this solution with ammonia water, + ammonium oxalate T. S. - white precipitate, insoluble in acetic acid, soluble in hydrochloric acid. Impurities: Carbonate, volatile substances. Should be kept dry, in air-tight containers.

Preparations. - 1. Liquor Calcis. Solution of Calcium Hydroxide. (Syn., Liq. Calc, Lime Water, Aqua Calcis, Solution of Lime, Calcaria Solutum; Fr. Eau (Liqueur) de Chaux; Ger. Aqua Calcariae, Kalkwasser.)

Manufacture: This aqueous solution (saturated) is prepared by slaking lime 50 Gm., with distilled water 1000 Ml. (Cc), gradually added, agitating occasionally for half an hour, allowing particles to subside, decanting and rejecting supernatant liquid; transfer magma to a filter, wash repeatedly with boiling distilled water until only faint cloudiness with silver nitrate T. S. (abs. of chloride), return magma to suitable container, add distilled water 5000 Ml. (Cc), agitate thoroughly, let stand 24 hours, agitate, let coarse particles subside, pour liquid, holding undissolved calcium hydroxide in suspension, into tightly-stoppered bottle, shake occasionally to insure saturation; pour off clear liquid as required; undissolved calcium hydroxide must not be used for making additional quantities of this solution unless it should assay full strength. It is a clear, colorless, odorless liquid, alkaline taste and reaction; contains .14-. 17 p. c. of calcium hydroxide-stronger when cold. Tests: 1. Absorbs carbon dioxide from the air, forming on its surface a pellicle of calcium carbonate. 2. Heat produces turbidity, due to separation of calcium hydroxide, which redis-solves on cooling. Impurities: Alkalies, alkali carbonates. Dose, ℥ss-4 (15-120 Ml. (Cc.)).

Prep.: 1. Linimentum Calcis. Lime Liniment. (Syn., Lin. Calc, Carron Oil; Fr. Liniment (Savon) calcaire; Ger. Kalkliniment.) Manufacture: 50 p. c. Mix by agitation lime water and linseed oil, each 50 Ml. (Cc); used externally.

Unoff. Preps.: Liquor Calcis Saccharatus (Br.), calcium hydroxide 5 p. c, sugar 10, water q. s. 100, dose, xv-60 (e1-4 Ml. (Cc)). Liquor Calcis Sulphuratae, calcium oxide 16.5 p. c, + sublimed sulphur 25, water q. s. 100. Syrupus Calcis, official 1880-1910, lime (5.5 p. c, sugar 35, water q. s. 100, dose, exv-60 (1-4 Ml. (Cc.)).

Properties and uses. - Lime - escharotic, depilatory, antacid, arrests putrefaction, hence added to stools of dysentery, cholera, typhoid fever, cesspools, sewers, ulcers, favus, psoriasis; Liquor-astringent, antacid; diarrhoea, diabetes, gravel, dyspepsia, scabies, Tinea capitis, ulceration of bladder, urethra, mucous and purulent discharges, ascarides of the rectum, chronic bronchitis, vomiting, nausea, prevents milk curdling in stomach, aphthae, thrush, typhoid fever, phthisis, rachitis, cutaneous eruptions, antidote to arsenic trioxide; Liniment - burns, scalded throat, etc.; Syrup - acute rheumatism, infantile diarrhoea, vomiting, urinary affections.

Calx Chlorinata. Chlorinated Lime. - (Syn., Calx Chlorin., Chloride of Lime (misnomer), Calx Chlorata, Calcium Hypochlorite Bleaching Powder, Oxymuriate of Lime, Chloris Calcicus, Chloru-retum Calcis, Calcis Chloridum, Calcii Hypochloris; Fr. Chlorure de Chaux, Poudre de Tennant ou de Knox; Ger. Calcaria chlorata, Chlorkalk, Bleichkalk.)

Manufacture: Powdered slaked lime is spread upon shelves arranged in boxes or chambers into which from the top chlorine gas is passed a -long as it is absorbed, at a temperature not above 25° C. (77° F.), to avoid formation of calcium chlorate - 2Ca(OH)2 + 4C1 = Ca(C1O)2 + ( aCl2 + 2H2O. It is a white, or grayish-white, granular powder, odor of chlorine, moist and gradually decomposed on exposure, when it should not be used or dispensed, partly soluble in water, alcohol, the insoluble portion readily settling when it is mixed with water, lumps readily break down; contains 30 p. c. of available chlorine. Tests: 1. Shake 1 Gm. with distilled water (50) - filtrate colors red litmus blue, then bleaches it. 2. Dissolve in diluted acetic acid - evolves abundance of chlorine, trifling residue remains undissolved; add to this solution ammonium oxalate T. S. - white precipitate, insoluble in acetic acid, soluble in hydrochloric acid. Should be kept cool, dry, in air-tight containers. Dose, gr. 1-5 (.06-.3 Gm.), in solution; mouth wash (1 p. c); lotion (3-5 p. c); ointment (10 p. c).