Uii+iv = 238.5.

The element uranium (fr. Gr.

the sky - i. e., in allusion to the planet Uranus) was discovered in 1789 in a mineral long known and called pitch-blend (uraninite), but which was supposed to be an ore of zinc or iron. Metal may be obtained by decomposing the chloride with potassium or sodium, is permanent, and belongs to the chromium group having, however, the appearance and color of nickel, sp. gr. 18.7; forms two classes of compounds - uranousii, uranic (uranyl)iv. Tests for Uranium Salts. - 1. Ammonium sulphide precipitates black uranic sulphide. 2. Hydrogen sulphide - no precipitate, but reduces yellow uranic to green uranous salt. 3. Alkaline carbonates - yellow precipitate. 4. Potassium ferrocyanide - reddish-brown precipitate; fused with borax - clear, yellow glass, greenish on cooling.

Uranii Nitras. Uranium Nitrate, UO2(NO3)2 + 6H2O. - (Syn., Uran. Nit., Uranyl Nitrate; Fr. Azotate de Urane; Ger. Urannitrat.)

Manufacture: Treat finely powdered pitch-blend with nitric acid, remove from solution the several associated metals (lead, barium, bismuth, iron, zinc, radium, polonium, etc.). It is in light yellow prisms, odorless, bitter, astringent taste, efflorescent, radio-active, soluble ,in alcohol, ether, water (1.2); aqueous solutions yellow, acid; contains 98 p. c. of pure salt. Tests: 1. Aqueous solution (1 in 20) with fixed alkali or ammonia water - yellow precipitate, insoluble in excess, but soluble in ammonium carbonate T. S.; with ammonium sulphide T. S. - dark brown precipitate; with sodium phosphate T. S. - yellow precipitate. 2. Aqueous solution 2 Ml. (Cc.) with sulphuric acid 2 Ml. (Cc), cool, add crystal of ferrous sulphate - dark brown color around the crystal. Impurities: Heavy metals, iron, manzinc, alkaline earths, uranous compounds, sulphate, etc. Should be kept dark, in well-closed containers. Dose, gr. 1/8-1/4 (.008-.016 Gm.). Properties and Uses. - Antidiabetic - diabetes, increases quantity and specific gravity of the urine, which contains albumin and glucose; violent poison, producing severe gastro-enteritis, nephritis, reduction of haemoglobin, degeneration of bloodvessels and viscera, and oxygenating power of the blood; chiefly as an indicator, volumetric solutions, to detect morphine, arsenic and phosphoric acids; use cautiously. ZINCUM. ZINC. Znii = 65.37. (Syn., Speltrum; Fr. Speltre, Zinc; Ger. Zink.)

The metal zinc (Ger. zinn, tin, with which it formerly was confounded) is official as thin sheets, irregular, granulated pieces, molded into thin pencils, or as fine powder. Occurs natively as sulphide (zinc-blend), ZnS, as carbonate (calamine), ZnCO3, as silicate, and as red oxide, and is obtained pure by subliming carbonate or oxide mixed with charcoal; the vaporized metal distils into receivers, where it solidifies. It is a bluish-white metal, crystalline fracture, in the form of thin sheets, irregular granulated pieces, molded into thin pencils, or in powder, sp. gr. 6.9-7.2 after it is rolled, tarnishes slowly with a film of oxide or carbonate, soluble in diluted sulphuric or hydrochloric acid with evolution of hydrogen and usually some insoluble residue; when heated at 100-150° C. (212-302° F.) becomes malleable, ductile; 49 above 200° C. (392° F.) becomes sufficiently brittle to be powdered in an iron mortar; at 414° C. (777° F.) melts, and at 940° C. (1724° F.) boils and may be distilled; contains 99 p. c. of pure metal. Impurities: Arsenic, antimony, phosphorus, sulphur.

Tests for Zinc Salts: 1. With ammonium sulphide - white precipitate (Zinc sulphide), soluble in mineral acids, not in acetic acid; only metal whose sulphide is white. 2. Caustic alkali, ammonia water - white precipitate (zinc hydroxide, Zn(OH)2), soluble in excess of reagent. 3. Solution of potassium ferrocyanide - white precipitate (dist. from Mg, Al - no precipitate).

Zinci Chloridum. Zinc Chloride, ZnCl2. - (Syn., Zinc.Chlor., Butter of Zinc; Fr. Chloruretum Zincicum, Chlorure de Zinc; Ger. Zincum chloratum, Zinkchlorid, Chlorzink.)

Manufacture: Boil zinc in hydrochloric acid until dissolved - 2Zn + 4HC1 = 2ZnCl2 + H4; the solution contains also iron and lead, which may be removed by adding nitric acid to form ferric chloride, and then zinc carbonate to precipitate ferric hydroxide, filtering, evaporating; may also be made by evaporating official solution of zinc chloride to dryness, adding near the end a little hydrochloric acid to avoid largely the formation of oxychloride. It is a white, nearly white, granular powder, porcelain-like masses, or molded into pencils, odorless; so intensely caustic as to make tasting dangerous unless dissolved in much water, very deliquescent; soluble in glycerin, water (.25), alcohol (1.3); aqueous solution (1 in 10) acid; when heated to 115° C. (239° F.) fuses to a clear liquid; at higher temperature partly volatilizes in dense, white fumes, partly decomposes with a residue of zinc oxide; contains 95 p. c. of pure salt. Tests: 1. Aqueous solution (1 in 20) with potassium ferrocyanide T. S. - white, gelatinous precipitate; with ammonium sulphide T. S. - white precipitate; with silver nitrate T. S. - white, curdy precipitate, insoluble in nitric acid, soluble in ammonia water; with ammonium carbonate T. S. - white precipitate, redissolved in excess of reagent. 2. Add to 5 Ml. (Cc.) of aqueous solution (1 in 10) sufficient potassium hydroxide T. S. to redissolve precipitate first formed, warm - no odor of ammonia. Impurities: Heavy metals, ammonium salts, oxychloride, sulphate, etc. Should be kept in small, glass-stoppered bottles. Dose, gr. 1/10-1/2 (.006-.03 Gm.).

Preparations. - 1. Liquor Zinci Chloridi. Solution of Zinc Chloride. (Syn., Liq. Zinc. Chlor., Burnett's Disinfecting Fluid; Fr. Chlorure de Zinc liquide, Solute de Burnett; Ger. Flussiges Chlorzink, Chlorzinklosung.)