Fig. 452. - Sodium carbonate crystal.

ally loses carbon dioxide; at boiling - entirely converted into normal sodium carbonate. Impurities: Heavy metals, carbonate. Should be kept cool, in well-closed containers. Dose, gr. 5-30 (.3-2 Gm.).

Preparations. - 1. Trochisci Sodii Bicarbonatis. Troches of Sodium Bicarbonate. (Syn., Troch. Sod. Bicarb., Fr. Tablettes (Pastilles) de Bicarbonate de Soude, Pastilles (de Vichy) digestif; Ger. Natron-pastillen.)

Manufacture: Triturate until fine powder myristica 1 Gm., sugar 54 Gm., gradually added, mix intimately with sodium bicarbonate 18 Gm., form mass with mucilage of tragacanth q. &., divide into 100 troches. Dose, 1-6 troches.

2. Caffeina Citrata Effervescens, 57 p. c. 3. Ferri Carbonas Sac-charatus, 35 p. c. 4. Potassii Citras Effervescens, 47.7 p. c. 5. Pulvis Effervescens Compositus, 38.5 gr. (2.5 Gm.). 6. Sodii Phosphas Effervescens, 47.7 p. c.

Unoff. Preps.: Liquor Sodae et Menthae, 5 p. c, + aromatic spirit of ammonia 1, spearmint water q. s. 100. Salia Effervescentia, 28-84.6 p. c. Sodii Citro-Tartras Effervescens (Br.), 51 p. c, dose, 3 j-2 (4-8 Gm.).

Properties. - Antacid, diuretic, slight depressant and sedative.

Uses. - Similar to potassium bicarbonate, but more slowly absorbed; dyspepsia, calculus, infantile croup, pneumonia, gravel, suppressed urine, diabetes, acute articular rheumatism, angina, pruritus, tonsillitis, ophthalmia, rhus toxicodendron poisoning, pain from burns, to dissolve diphtheritic membrane.

Incompatibles: Acids, acid salts, bismuth subnitrate.

Sodii Hydroxidum. Sodium Hydroxide, NaOH. - (Syn., Sod. Hy-drox., Caustic Soda, Sodium Hydrate, Soda, U. S. P. 1890, Soda Caustica, Natrium (Causticum) Hydricum; Fr. Soude caustique; Ger.

Natron, Atznatron.)

Manufacture: (1) Decompose a solution of sodium carbonate with milk-of lime, evaporate filtrate, congeal in molds; (2) allow metallic sodium to act on water - Na + H2O = NaOH + H; (3) evaporate liquor sodii hydroxidi, pour into molds. It is in dry, white, nearly white, fused masses, sticks, hard, brittle, showing crystalline fracture (must exercise great caution in its use, as it rapidly destroys organic tissues), deliquescent, absorbs carbon dioxide becoming coated with carbonate, soluble in water (.9), boiling water (.3), alcohol; solution, even greatly diluted, strongly alkaline, produces intensely yellow flame; contains 90 p. c. of pure salt. Impurities: Potassium, organic matter, insoluble substances. Should be kept in well-closed containers, and if these are bottles they must be of hard glass. Dose, gr. 1-2 (.06-. 13 Gm.), well diluted.

Preparations. - 1. Liquor Sodii Hydroxidi. Solution of Sodium Hydroxide. (Syn., Liq. Sod. Hydrox., Liquor Sodae, Solution of Soda, Solution of Sodium Hydrate, Natrium Hydricum Solutum, Solution of Caustic Soda; Fr. Soude caustique liquide, Lessive des Savonnier; Ger. Liquor Natri caustici, Atznatronlauge.)

Manufacture: 5 p. c. Dissolve sodium hydroxide 5.6 Gm. in distilled water q. s. 100 Gm. It is a clear, colorless, odorless, aqueous liquid (solution), very acrid, caustic taste (even if largely diluted, when it only should be tasted), strongly alkaline, readily absorbs carbon dioxide from the air, sp. gr. 1.056; contains not less than 4.5 p. c. of sodium hydroxide. Impurities: Carbonate, etc. Should be kept in bottles made of hard glass, with rubber stoppers, or glass stoppers coated with petrolatum. Dose, ev-30 (.3-2 Ml. (Cc.)), well diluted.

Unoff. Prep.: Soda cum Calce, 50 p. c, + calcium oxide 50.

Properties. - Strong escharotic, destroys tissue like potassium hydroxide, and otherwise just like it only not quite so poisonous.

Poisoning, Incompatibles: Same as for potassium hydroxide.

Sodii Acetas. Sodium Acetate, NaC2H3O2 + 3H2O. - (Syn., Sod. Acet, Acetas Sodicus (Natricus), Terra Foliata Tartari (Crystallisata); Fr. Acetate de Soude; Ger. Natrium aceticum, Natriumacetat, Essigsaures Natron.)

Manufacture: Neutralize acetic acid with sodium carbonate or bicarbonate, evaporate, crystallize - Na2CO3 + 2HC2H3O2 = 2NaC2H3O2 + H2O + CO2, or from acetic acid in purifying wood vinegar. It is in colorless, transparent, monoclinic prisms, granular, crystalline powder, odorless, cooling, saline taste, efflorescent, soluble in water (.8), alcohol (19); aqueous solution (1 in 20) neutral, slightly alkaline; contains 59.97-62.96 p. c. of anhydrous sodium acetate, corresponding to 99.5 p. c. of crystallized salt. Tests: 1. Begins to liquefy at 58° C. (137° F.), becomes dry and anhydrous at 120° C. (248° F.), at higher temperature decomposes with inflammable, empyreumatic vapors, and black residue of sodium carbonate and carbon, which gives intense yellow flame, is alkaline and effervesces with acids. 2. Add .1 Gm. to sulphuric acid and alcohol each 1 Ml. (Cc), warm - ethyl acetate, recognized by odor. Impurities: Heavy metals, arsenic, potassium. Should be kept in well-closed containers. Dose, gr. 15-60 (1-4 Gm.).

Properties and Uses. - Diuretic, rarely used in medicine, but to distil with sulphuric acid for acetic acid.

Sodii Citras. Sodium Citrate, Na3C6H5O7 + 2H2O. - (Syn., Sod. Cit., Natrium Citricum; Fr. Citrate de Sodium (Soude); Ger. Natrium-citrat, Citronensaures Natron.)

Manufacture: Neutralize a solution of citric acid with sodium carbonate or bicarbonate, concentrate, crystallize. It is in small crystals, a white, granular powder, odorless, cooling, saline taste, soluble in water (1.3), boiling water (.6), insoluble in alcohol; aqueous solution (1 in 20) slightly alkaline to litmus, not reddened by 1 drop

Fig. 453. - Sodium acetate crystal.