The element chromium (Gr.

Chromium Crii VI 52 903

color, + ium - i. e., salts are colored) is not or much service in medicine, as it enters into only one official compound. Natively it occurs mostly as chrome iron ore or chromite, FeO,Cr2O3, having analogous composition to magnetic iron ore, FeO,Fe2O3; forms two basic oxides, chromous, CrO, and chromic, Cr2O3, and an acid oxide, trioxide, CrO3 (official); there is also the dioxide, CrO2, and trichromic tetroxide, Cr3O4.

Tests for Chromium Salts: 1. NaOH, KOH, NH4OH, and NH4SH frill each precipitate green chromic hydroxide, Cr2(OH)6. 2. Soluble lead salts precipitate lead chromate (chrome yellow), PbCrO4, insoluble in acetic acid, soluble in HC1 and NaOH.

Chromii Trioxidum. Chromium Trioxide, CrO3. - (Syn., Chrom. Triox., Chromic Acid (Anhydride), Acidum Chromicum, Anhydrous Chromic Acid; Fr. Acide chromique; Ger. Acidum chromicum, Chromsaure.)

Manufacture: Heat together, to solution, potassium dichromate (30), water (50), sulphuric acid (77.5), let stand 12 hours, drain crystals - K2Cr2O7 + 2H2SO4 = 2CrO3 + 2KHSO4 + H2O. Chromic acid proper, H2CrO4, like arsenous and carbonic acids, can exist only in solution and upon evaporating this the acid becomes anhydride. It is in small, needle-shaped crystals, rhombic prisms, dark purplish-red, metallic lustre, odorless, destructive to animal and vegetable tissues, deliquescent, soluble in water (.6), boiling water (.5); decomposes in contact with organic solvents (alcohol, ether, glycerin), sometimes with dangerous violence (liberated oxygen); contains 95 p. c. of the salt. Tests: 1. Heat - dark, black, restored on cooling; fuses at 193° C. (380° F.) to reddish-brown liquid, which on cooling - dark red, brittle mass (often enclosing cavities filled with crystals), furnishing a scarlet powder. 2. Decomposes at 250° C. (482° F.) into green chromic oxide and free oxygen; protracted heating - residue (chromic oxide); warmed with hydrochloric acid - evolves chlorine. Impurities: Sulphuric acid, etc. Should be kept in glass-stoppered bottles, and not brought in contact with organic substances, as serious accidents might result. Dose, gr. 1/8 - 1/4 (.008-.016 Gm.).

Preparation. - (Unoff.): Liquor Acidi Chromid (Br.), 25 p. c.

Properties and Uses. - Antiseptic, disinfectant, deodorant, escha-rotic, astringent; coagulates albumin. Used externally on growths in the mouth, larynx, pharynx, nasal passages (polypi), rhinitis, gangrene, scorbutic, syphilitic, or gangrenous ulcers, tumors, bites of rabid animals, poisoned wounds, tineae, sycosis, lupus, sweating or tender feet, conjunctivitis, uterine hemorrhage, leucorrhoea, gonorrhoea, incontinence of urine. The aqueous solution is used mostly, 5-10 p. c, or even varying up to the strong acid.

Poisoning: Similar to potassium dichromate. Give emetics, then magnesium oxide or carbonate, sodium bicarbonate or borate, demulcent drinks (milk, egg-white), stimulants, heat, opium, stimulant enemas.