Preparation. - 1. Pulvis Jalapae Compositus, 65 p. c.

Potassii et Sodii Tartras. Potassium and Sodium Tartrate, KNaC4H4O6 + 4H2O. - (Syn., Pot. et Sod. Tart., Rochelle Salt, Tartarated Soda, Natrokali Tartaricum, Soda Tartarata, Sal Poly-chrestum Seignetti, Tartras Potassico-sodicus; Fr. Sel de Seignette,

Soude Tartarisee; Ger. Tartras natronatus, Kali-umnatriumtartrat, Seignettesalz.)

Manufacture: Add potassium bitartrate to hot solution of sodium carbonate, to neutralize free acid, thus obtaining normal double tartrate - 2KHC4H4O6+ (Na2CO3+10H2O) = 2(KNaC4H4O6, 4H2O) + CO2 + 3H2O; practically 8 parts potassium bitartrate + 6 sodium carbonate crystals yield 12 crystallized Rochelle salt. It is in colorless, transparent, rhombic prisms, or white powder, odorless, cooling saline taste, crystals slightly efflorescent in dry air, soluble in water (.9), almost insoluble in alcohol; aqueous solution (1 in 20) alkaline to litmus, not reddened by a drop of phenolphthalein T. S.; contains 73.72-77.39 p. c. of anhydrous potassium and sodium tartrate, corresponding to 99 p. c. of crystallized salt. Tests: 1. Heat to 74° C. (165° F.) - fuses to colorless liquid, which at higher heat froths, becomes brown, gradually carbonizes, emitting inflammable vapors of burning-sugar odor, residue consisting of potassium and sodium carbonates with carbon, imparting intensely yellow flame. 2. Aqueous solution (1 in 10) with acetic acid - white, crystalline precipitate; with silver nitrate T. S. - white precipitate, black on boiling. Impurities: Heavy metals, lead, ammonia, etc. Should be kept in well-closed containers. Dose, aperient, 3ij-4 (8-15 Gm.); hydragogue cathartic, ℥j (30 Gm.).

Preparation. - 1. Pulvis Effervescens Compositus. Compound Effervescing Powder. (Syn., Pulv. Eff. Co., Seidlitz Powder, Pulveres Effervescentes Aperientes; Br. Pulvis Sodae Tartaratae Effervescens, Effervescent Tartarated Soda Powder; Fr. Poudre gazifere purgative, Poudre de Seidlitz; Ger. Pulvis aerophorus, Laxans or Seidlitzensis, Brausepulver Abfiihrendes, Seidlitzpulver.)

Manufacture: Mix thoroughly sodium bicarbonate gr. 38.5 (2.5 Gm.) with potassium and sodium tartrate gr. 115.5 (7.5 Gm.), wrap in blue paper; then wrap in white paper tartaric acid gr. 33.5 (2.2 Gm.); contains (blue paper) 9.5-10.5 Gm.; 23-27 p. c. of sodium bicarbonate, 73-78 p. c. of potassium and sodium tartrate. Test: 1. Aqueous solution of blue paper contents (1 in 20) and acetic acid, each 5 Ml. (Cc), after effervescence shake vigorously - white, crystalline precipitate, soluble in ammonia water. Should be kept dry, in well-closed containers. Dose, 1 powder; dissolve contents of the blue paper in a half-glass of water (ordinary temperature), and to this add contents of the white paper - drink while effervescing.

Properties. - Cream of tartar, Rochelle salt, and Seidlitz powders are all diuretic, purgative, refrigerant, antilithic.

Fig. 444.   Rochelle salt crystal.

Fig. 444. - Rochelle salt crystal.

Uses. - Febrile diseases, dropsy, hemorrhoids, vomiting from gastric acidity and pregnancy. Cream of tartar is believed to be eliminated from the system unchanged, hence not so good when alkalinity desired for blood and urine. Small and frequent doses of Rochelle salt simply make urine alkaline.

Potassii Chloras. Potassium Chlorate, KClO3. - (Syn., Pot. Chloras, Kali Oxymuriaticum, Kali Muriaticum Oxygenatum, Chloras (Potas-sicus) Kalicus, Hyperoxymuriate of Potassa; Fr. Chlorate de Potasse; Ger. Kalium chlo-ricum, Kaliumchlorat, Chlorsaures Kali.)

Manufacture: Pass chlorine into water holding lime (preferably magnesium oxide) in suspension, thereby forming chloride and hypochlorite, the latter by heat being converted into chlorate and chloride, treat solution with potassium chloride, giving potassium chlorate which crystallizes out, and potassium (magnesium) chloride that remains in solution; magnesium is preferred, as potassium chlorate is less soluble in solution of magnesium chloride than of calciumchloride - 2Ca(OH)2+Cl4=Ca(CIO)2+CaCl2+2H2O;3Ca(ClO)2 = Ca(ClO3)2 + 2CaCl2; Ca(ClO3)2 + 2KC1 = 2KClO3 + CaCl2. May also be made by passing electric current into solution potassium chloride. It is in colorless, lustrous, monoclinic prisms, plates, or white granular powder, odorless, saline taste, permanent, soluble in glycerin, water (11.5), boiling water (1.8), almost insoluble in alcohol; aqueous solution (1 in 20) neutral; contains 99 p. c. of pure salt. Tests: 1. When heated - melts giving off oxygen, leaving residue of potassium chloride, readily soluble in water, and yielding with silver nitrate T. S. a white precipitate, insoluble in nitric acid, soluble in ammonia water; imparts violet flame; add .2 Gm. to hydrochloric acid 1 Ml. (Cc.) - deep greenish-yellow color, chlorine evolved. 2. Aqueous solution (1 in 20) with excess of tartaric acid T. S. - scant, white, crystalline precipitate (slowly); with platinic chloride T. S. - yellow crystalline precipitate. Impurities: Heavy metals, etc. Should be kept in well-closed containers, and handled cautiously, as dangerous explosions may occur if heated, subjected to concussion or triturated with organic substances (cork, tannin, dust, sugar, sulphur, antimony sulphide (sulphides), phosphorus, hypophosphites, catechu, glycerin, etc. Dose, gr. 5-20 (.3-1.3 Gm.).

Preparations. - 1. Trochisci Potassii Chloratis. Troches of Potassium Chlorate. (Syn., Troch. Pot. Chlorat.; Br. Trochiscus Potassii Chloratis; Fr. Tablettes (Pastilles) de Chlorate de Potasse; Ger. Pastillen von Chlorsaurem Kali, Kaliumchloratpastillen.)

Manufacture: Triturate together sugar 60 Gm., tragacanth 3 Gm., transfer to a sheet of paper and, by means of a bone or wooden spatula, mix with potassium chlorate 15 Gm., avoiding hard trituration or

Fig. 445.   Potassium chlorate crystal.