Nai = 23.

The metallic element sodium (L. sod-a, + ium, fr. solidus, contr. sodo, solid, hard, sod-ash, residue from burning masses or sods of marine plants) is not itself official, but many of its salts are. It is diffused widely in nature in the form of various compounds, occurring in the atmosphere, soil, spring- and sea-waters, rock and common salt, mainly as the chloride; there is also the native nitrate and silicate, all being more abundant and soluble than potassium salts, and, like them, dissolved by rain-water, which, in its onward movement, dissolves and deposits some of them almost everywhere. The metal is obtained similarly to potassium (heating carbonate with carbon, etc.), with which it is distributed universally.

Tests for Sodium Salts. - 1. Sodium salts are all soluble in water, consequently cannot be precipitated by any reagent. 2. The main test is that all compounds impart a yellow color to a colorless Bunsen flame, and the spectroscope gives a characteristic yellow line. 3. Sodium compounds are white, soluble in water, and non-volatile at a red heat.

Sodii Boras. Sodium Borate, Na2B4O7 + 10H2O. - (Syn., Sod. Bor., Borax, Sodium Tetraborate (Pyroborate), Sodae Biboras, Sodium Biborate, Natrium Biboricum (Biboracicum), Boras Sodicus; Fr.

Borate de Soude, Sel de Perse; Ger. Borsaures Natron, Natrium (pyro-borat)-borat.)

Manufacture: This salt, natively called tincal, is found in Thibet, Persia, Ca'ifornia, etc., occurring as a saline incrustation on lake shores and as crystals in the blue mud of Clear Lake. The large crystals are picked out, washed with sodium hydroxide solution to remove fatty matter, and the saturated earth lixiviated, the solution evaporated and crystallized; may also be made from the natural borates - boracite, borosodocalcite, crystomor-phite, etc., of Nevada, S. America, Europe, Asia. Mostly prepared from crude boric acid of Tuscany by fusing with sodium carbonate - 4H3BO + Na2CO3 = Na2B4O7 + CO2 + 6H2O. It is in colorless, transparent, mono-clinic prisms, white powder, odorless, sweetish, alkaline taste, slightly efflorescent in warm, dry air, soluble in water (15), boiling water (.6), glycerin (1), insoluble in alcohol; contains 52.32-54.92 p. c. of anhydrous sodium borate, corresponding to 99 p. c. of crystallized salt. Tests: 1. When heated - at first loses part of water of crystallization, then melts, swells, forming white, porous mass; at red heat - loses all water of crystallization, fusing to colorless glassy mass. 2. Produces intense yellow flame, while a borax bead on platinum wire, dipped in glycerin, gives a transient bright green flame. 3. Aqueous solution (1 in 20) alkaline, turns turmeric paper reddish-brown, but if solution acidified with hydrochloric acid, turmeric paper remains unchanged at first, but brownish-red on drying, and greenish-black on moistening with ammonia water. Impurities: Heavy metals, arsenic, carbonate, bicarbonate. Should be kept in well-closed containers. Dose, gr. 5-30 (.3-2 Gm.). Preparations. - 1. Unguentum Aquae Rosae, 5 p. c. Unoff. Preps.: Liquor Sodii Boratis Compositus (Dobell's Solution), 1.5 p. c, + sodium bicarbonate 1.5, liquefied phenol .3, glycerin 3.5, water q. s. 100. Mel Sodii Boratis, 10 p. c, + glycerin 5, clarified honey 85. Mel Rosae et Sodii Boratis, 10 p. c, -+- glycerin 5, honey of rose 85. Glycerinum Boracis (Br.), 16 2/3 p. c. Sodii Boro-Benzoas, 43 p. c, + sodium benzoate 57.

Properties and Uses. - Identical with boric acid, disinfectant, antiseptic, astringent - dysmenorrhea, uric acid diathesis, epilepsy, gravel; locally in aphthous ulceration, diphtheria, inflammation of the mouth, infantile diarrhoea, cystitis, ulcers, urethral and vaginal inflammations, scaly skin diseases (psoriasis, impetigo, eczema, etc.), prurigo pudendi, leucorrhoea, itching in urticaria, pruritus scroti et ani, conjunctivitis, gonorrhoea.

Incompatibles: Precipitates alkaloids, atropine, cocaine, morphine, quinine, etc., except in presence of glycerin, gelatinizes acacia, muci-

Fig. 451. - Sodium borate crystal.

lage, decomposes alkali carbonates with effervescence, in presence of glycerin.

Sodii Perboras. Sodium Perborate, NaBO3 + 4H2O. - (Syn., Sod. Perbor.; Fr. Perborate de Soude; Ger. Natriumperborate.)

Manufacture: Mix boric acid (248), sodium peroxide (78), add these to cold water (2000) acidified with sulphuric acid (or carbon dioxide), wash separated crystals with alcohol, dry at 58° C. (136° F.). It is in white, crystalline granules, powder, odorless, saline taste, stable in cool dry air, but decomposed, evolving oxygen in warm moist air, soluble in water; saturated aqueous solution alkaline, decomposes into nictaborate and hydrogen dioxide, gradually evolving oxygen, more rapidly when solution warmed - NaBO3 + H2O = H2O2 + NaBO2; contains 9 p. c. of available oxygen, corresponding to 86.5 p. c. of pure salt. Tests: 1. Produces intensely yellow flame; turmeric paper moistened with acidulated (HCl) aqueous solution - brown, particularly on drying; on moistening dried test paper with ammonia water - color changed to greenish-black. 2. Shake aqueous solution (1 in 50) with diluted sulphuric acid each 1 Ml. (Cc), + few drops of potassium dichromate T. S., + ether 2 Ml. (Cc.) - latter blue color. Impurities: Heavy metals, etc. Should be kept cool, in well-closed containers. Dose, gr. 1-2 (.06-.13 Gm.); chiefly externally.

Properties and Uses. - Antiseptic, deodorant, bactericide; wounds, purulent sores, varicose ulcers, toilet preparations, bleaching, disinfecting; similar to hydrogen dioxide, with the advantage of yielding an alkaline solution; applied as dusting powder, or in 2 p. c. solution.

Sodii Chloridum. Sodium Chloride, NaCl. - (Syn., Sod. Chlorid., Common (Table, Sea) Salt, Muriate of Sodium, Sal (Commune) Culinare, Chloruretum Sodicum; Fr. Chlorure de Sodium, Hydro-chlorate de Soude, Sel de Cuisine, Sel commun or marin; Ger. Natrium chloratum (purum),. Natriumchlorid, Chlornatrium, Kochsalz.)