Srii = 87.6.

The element strontium (L. fr. strontian, in Argyleshire, Scotland, where first found as strontianite, SrCO3) in the form of its compounds was not until recently used to any extent in medicine. It occurs natively as sulphate (celestite, SrSO4) and carbonate. The metal itself is yellow, malleable, harder than lead, sp. gr. 2.5, oxidizes quickly when exposed, hence has to be kept under naphtha, like the alkali metals. The salts can be produced in a manner similar to those of barium, thus: Heat strontium sulphate with carbon, which gives strontium sulphide; this sulphide dissolved in HCl yields the chloride, which by double decomposition with Na2CO3 gives pure strontium carbonate (strontii carbonas), SrCO3, 99 p. c. purity, from which the official salts are made.

Tests for Strontium Salts: 1. With alkaline carbonates, oxalates, or phosphates get white precipitate. 2. With calcium sulphate get white precipitate of SrSO4. 3. With H2SO4 or a soluble sulphate get white precipitate. 4. Add potassium chromate and get yellow precipitate, SrCrO4, soluble in acids; here K2Cr2O7 gives no precipitate. 5. Gives a beautiful red color to flame.

Strontii Bromidum. Strontium Bromide, SrBr2 + 6H2O. - (Syn., Stront. Brom.; Fr. Bromure de Strontium; Ger. Strontium-bromid.)

Manufacture: Dissolve strontium carbonate in hydrobromic acid until neutralized, evaporate, crystallize - SrCO3 + 2HBr = SrBr2 + H2O + CO2. It is in colorless, transparent, hexagonal crystals, odorless, bitter, saline taste, deliquescent (moist air), efflorescent (dry air), soluble in alcohol, water (.35), insoluble in ether; aqueous solution (1 in 20) neutral; contains 98 p. c. of pure salt. Tests: 1. Quickly heated - melts, and above 180° C. (356° F.) loses all water of crystallization; produces intensely crimson flame. 2. Aqueous solution (1 in 10) with silver nitrate T. S. - yellowish-white precipitate, insoluble in nitric acid or moderate excess of ammonia water; aqueous solution (1 in 20) with calcium sulphate T. S. - slowly a white precipitate (strontium sulphate), insoluble in dilute acids; diluted sulphuric acid or readily soluble sulphate gives quicker precipitate. Impurities: Heavy metals, barium, iodine, bromate. Should be kept in well-closed containers. Dose, gr. 10-30 (.6-2 Gm.).

Properties and Uses. - Similar to potassium bromide - epilepsy, gastric disorders, albuminuria.

Strontii Iodidum. Strontium Iodide, Srl2 + 6H2O. - (Syn., Stront. Iod.; Fr. Iodure de Strontium; Ger. Strontiumjodid.)

Manufacture: Dissolve strontium carbonate in hydriodic acid until neutralized, evaporate, crystallize - SrCO3 +2HI = SrI2 + H2O +CO2. It is in colorless, transparent, hexagonal plates, white, granular powder, crystalline crusts, odorless, bitter, saline taste, deliquescent and yellowish on exposure, soluble in water (.2), alcohol, slightly in ether; aqueous solution (1 in 20) neutral, slightly alkaline; contains 99 p. c. of pure salt. Tests: 1. Cautiously heated - crystals melt and gradually lose water of crystallization; at red heat - decomposed, losing iodine with residue of strontium oxide; produces intensely crimson flame. 2. Aqueous solution (1 in 10) with calcium sulphate T. S. - slowly a white precipitate (strontium sulphate), insoluble in dilute acids; diluted sulphuric acid or readily soluble sulphate gives quicker precipitate. 3. Aqueous solution (1 in 20) 5 Ml. (Cc.) with ferric chloride T. S. 1 Ml. (Cc.) - iodine liberated, which imparts violet color to chloroform, when shaken with it. Impurities: Heavy metals, barium, bromide, chloride, cyanide. Should he kept dark, in small, amber-colored, glass-stoppered bottles. Dose, gr. 10-30 (.0-2 Gm.).

Properties and Uses. - Alterative; does not irritate intestinal tract or depress nutrition; may be substituted for potassium iodide.

Strontii Salicylas. Strontium Salicylate, Sr(C7H5O3)2 + 2H2O. - (Syn., Stront. Salicyl.; Fr. Salicylate de Strontium; Ger Strontium salicylicum (salicylsaures.)

Manufacture: Dissolve salicylic acid (10) in hot water (100), add strontium carbonate (5.34), heat until effervescence ceases, filter, evaporate to crystallization. It is a white, crystalline powder, odorless, somewhat sweet, saline taste, soluble in water (19), boiling water (3.7), alcohol (61), boiling alcohol (14); contains, when dried to constant weight, 99 p. c. of pure salt. Tests: 1. When heated - decomposes with inflammable vapors of phenol odor, and residue of strontium carbonate and carbon; produces intensely red flame. 2. Aqueous solution (1 in 20) colorless, with calcium sulphate T. S. - slowly a white precipitate (strontium sulphate), insoluble in dilute acids. 3. Concentrated aqueous solution with a few drops of ferric chloride T. S. - dark red color and a precipitate; with diluted hydrochloric acid - voluminous, white precipitate (salicylic acid); aqueous solution (1 in 100) - deep violet-blue color. Impurities: Heavy metals, barium. Should be kept cool, dark, in well-closed containers. Dose, gr. 10-30 (.6-2 Gm.).

Properties and Uses. - Antirheumatic, tonic; rheumatism, gout, chorea, muscular pains, pleurisy, intestinal fermentation.

Incompatibles: Ferric salts, lime water, spirit nitrous ether, mineral acids, solutions of quinine salts, lead acetate, silver nitrate, sodium phosphate.

Allied Salts:

1. Strontii Lactas. Strontium Lactate, Sr(C3H5O3)2 + 3H2O). - Obtained by dissolving strontium carbonate in lactic acid until neutralized, evaporate, crystallize - SrCO3 + 2HC3H5O3 = Sr(C3H5O3)2 + H2O+CO2. It is a white granular powder, or in crystalline nodules, odorless, bitter, saline taste, permanent; soluble in water (4), also in alcohol. By heat decomposes into carbonate, which effervesces with HC1. Impurities: Barium, carbonate, oxalate, chloride, butyrate, propionate, arsenic, lead, iron, aluminum. Incompatibles: Carbonate and sulphate solutions; potassium chromate. Diuretic; nephritis, albuminuria, rheumatism, gout, causes disappearance of the urates. Dose, gr. 10-30 (.6-2 Gm.), ter die.