quescent when exposed to moist air. Solubility.-In 0.5 part of water; in 0.5 part of boiling. water; 1.8 parts of Alcohol; 30 parts of Ether. Citric Acid, like Tartaric Acid, is often used to produce an effervescing mixture with Ammonium, Sodium or Potassium Carbonates, the two solutions being mixed immediately before taking. Carbon Dioxide, which causes the effervescence, is formed thus: 3KHCO3+H3C6H5O7=K3C6H5O7+3CO2+3H2O. IMPURITIES. Sulphuric, tartaric and oxalic acids, iron, calcium, lead, heavy metals. INCOMPATIBLES.-Potassium tartrate, mineral acids, alkaline carbonates, sulphides, acetates. Citric Acid is used to make Caffeina Citrata, Caffeina Citrata Effervescens, Liquor Magnesii Citratis, Liquor Potassii Citratis, Potassii Citras Effervescens, Sodii Phosphas Effervescens, Syrupus Aurantii, and Syrupus Lactucarii. Dose, 0.500 gm. = 500 milligm. (8 gr.). Preparation Syrupus Acidi Citrici.—Syrup of Citric Acid. Abv.-Syr. Acid. Cit. Citric Acid, 10; Distilled Water, 10; Tincture of Lemon Peel, 10; Syrup to 1000. 8. ACIDUM TARTARICUM.-Tartaric Acid. Abv.-Acid. Tart. H2C4H1O=150.05. A dibasic organic acid [C2H2(OH)2(COOH)2], usually prepared from argol. It contains not less than 99.5 per cent. of pure Tartaric Acid. SOURCE. Boil Acid Potassium Tartrate with Calcium Carbonate. 2KHC4H4O6+CaCO3=CaC4H4Oь+K2C4H2O6+H2O+CO2. Calcium Chloride is now added, which precipitates more Calcium Tartrate. K2C4H4O6+CaCl2 = CaC4H4O6+2KCl. The Calcium Tartrate is finally decomposed with Sulphuric Acid. CaC4H4O6+H2SO4=H2C4H4O6+CaSO4. Then evaporate the fluid to the sp. gr., of 1.21. Separate the Calcium Sulphate crystals that form. Again evaporate, Tartaric Acid crystallizes out. CHARACTERS.-Colorless, translucent, monoclinic prisms, or as a white granular or fine powder, odorless, and having an acid taste. Solubility. In 0.75 part of water and in 3.3 parts of alcohol; in about 0.5 part of boiling water; slightly in Ether; almost insoluble in Chloroform. IMPURITIES.-Oxalic and sulphuric acids, iron, calcium, lead, heavy metals. INCOMPATIBLES.-Potassium salts, calcium, mercury, lead, vegetable astrin gents. Dose, 0.500 gm. = 500 milligm. (8 gr.). Tartaric Acid is used to make Acidum Hydriodicum Dilutum, Caffeina Citrata Effervescens, Potassii Citras Effervescens, Pulvis Effervescens Compositus, and Sodii Phosphas Effervescens. 9. ACIDUM LACTICUM.-Lactic Acid.—Abv. Acid. Lact. A liquid containing Lactic Acid, and lactic anhydrides equivalent to a total of not less than 85 per cent. nor more than 90 per cent. of Lactic Acid (CH, CHOH COOH = 90.05). SOURCE.-Usually obtained by subjecting milk-sugar or grape-sugar to lactic fermentation. CHARACTERS.-A colorless, or slightly yellow syrupy liquid, nearly odorless, of an acid taste, and absorbing moisture on exposure to damp air. Sp. gr., about 1.206. It is miscible with water, Alcohol or Ether. IMPURITIES.-Chlorides, sulphates, phosphoric, tartaric, citric, oxalic, or sarcolactic acid, butyric and other fatty acids, glycerin, sugars, heavy metals, organic impurities. Dose, 2 mils (30 m). Lactic Acid is used in Syrupus Calcii Lactophosphatis. For the Therapeutics of the Acids see p. 470. CLASS II. THE ANTISEPTIC ACID This is often im 1. ACIDUM BORICUM.-Boric Acid. Abv.-Acid. Bor. properly called Boracic Acid. H3BO3=62.02. It should contain not less than 99.5 per cent. of Boric Acid [B(OH)3]. SOURCE.-Native from Northern Tuscany, or made by the action of Hydrochloric Acid on Borax by filtration and recrystallization. Na2B4O7+2HCl+ 10H2O=4H2BO3+2NaCl+5H2O. CHARACTERS.-Transparent, colorless scales, of a somewhat pearly lustre, or six-sided, triclinic crystals, or as a white, very bulky powder, slightly unctuous to the touch, odorless, and having a faintly bitter taste. Solubility.—In 18 parts of water; 4 of Glycerin; 18 of Alcohol; 4 parts of boiling water and 6 parts of boiling Alcohol. IMPURITIES.-Chlorides, sulphates, iron, magnesium, calcium, arsenic, heavy metals. INCOMPATIBLES.-Alkaline hydroxides, carbonates and earths. 1. Glyceritum Boroglycerini.—Glycerite of Boroglycerin. Abv.— Glycer. Boroglyc. Synonyms.-Glycerite of Glyceryl Borate. Solution of Boroglyceride. Boric Acid, 310; Glycerin to 1000. 2. Unguentum Acidi Borici.-Ointment of Boric Acid. Abv.-Ung. Acid. Bor. Boric acid, 100; Paraffin, 50; White Petrolatum, 850. 2. SODII BORAS.-Sodium Borate. Abv.-Sod. Bor. Na2B4O7+10H2O= 382.16. Synonyms.-Borax. Sodium Tetraborate. Sodium Pyroborate. It contains not less than 52.32 per cent. nor more than 54.92 per cent. of anhydrous Sodium Borate, corresponding to not less than 99 per cent. of crystallized salt. SOURCE.-Native, as a saline incrustation on the shores of certain lakes and as a crystalline deposit at the bottom of the Borax lake of California, or by boiling together Boric Acid and Sodium Carbonate and crystallization. 4HзBO3+ Na2CO3 Na2B4O7+CO2+6H2O. CHARACTERS.-Colorless, transparent, monoclinic prisms, or as a white, powder, odorless and having a sweetish, alkaline taste. Solubility.-In 15 parts of water and 0.6 part of boiling water; in 1 part of Glycerin; insoluble in Alcohol. IMPURITIES.-Sodium carbonate, bicarbonate, nitrate and phosphate. INCOMPATIBLES.-Mineral acids, metallic and alkaloidal salts, mucilage of Sodium Borate is contained in Unguentum Aquæ Rosæ. 3. SODII PERBORAS.-Sodium Perborate. Abv.-Sod. Perbor. It contains not less than 9 per cent. of available oxygen, corresponding to about 86.5 per cent. of NaBO3+4H2O=154.06. SOURCE.-Boric Acid and Sodium Peroxide are gradually added to cold water; the precipitate thus formed is treated with a mineral acid and Sodium Perborate crystallizes out. CHARACTERS.-White, crystalline granules, or as a powder, odorless and having a saline taste. It is stable in cool and dry air, but is decomposed, with the evolution of oxygen, in warm or moist air. Solubility. It is soluble in water. Dose, 0.06 gm. = 60 milligm. (1 gr.). For the Therapeutics of Boric Acid and Sodium Borate and Perborate see p. 318. DIVISION II: THE METALS GROUP I The Alkali Metals: Potassium, Sodium, Lithium, Ammonium I. POTASSIUM 1. POTASSII HYDROXIDUM.-Potassium Hydroxide. Abv.-Pot. Hydrox. KOH=56.11. Synonyms.-Caustic Potash. Potassium Hydrate. It should contain not less than 85 per cent. of anhydrous Potassium Hydroxide. SOURCE.-Evaporate Liqour Potassæ, fuse the residue and pour into clean cylindrical moulds, which have been previously warmed. CHARACTERS.-Dry, white, or nearly white, fused masses, or in sticks, hard and brittle, showing a crystalline fracture; odorless. Great caution is necessary in handling it, as it rapidly destroys organic tissues. Exposed to the air, it rapidly absorbes Carbon Dioxide and moisture and deliquesces. Solubility.— In about 0.9 part of water and in 3 parts of Alcohol: soluble in 0.6 part boiling water and very soluble in boiling Alcohol. IMPURITIES.-Potassium carbonate. heavy metals. Preparation Liquor Potassii Hydroxidi.—Solution of Potassium Hydroxide. Abv.-Liq. Pot. Hydrox. An aqueous solution, containing not less than 4.5 per cent. of Potassium Hydroxide. SOURCE. Dissolve Potassium Hydroxide (of the full strength and quality directed by the U. S. P.), 60, in distilled water, 940. CHARACTERS.—A clear colorless liquid, odorless, and having, even when diluted, a very acrid and caustic taste, and a strongly alkaline reaction. It should not be tasted unless largely diluted. It absorbs Carbon Dioxide from the air. Sp. gr. about 1.046. INCOMPATIBLES.—Acids, acid salts, metallic salts and preparations of ammonia, belladonna, hyoscyamus and stramonium, the alkaloids of these being decomposed by caustic potash. Dose, 1 mil (15 M). For the Therapeutics of Potassium Hydroxide see p. 364. K2 2. POTASSII CARBONAS.-Potassium Carbonate. Abv.-Pot. Carb. CO3=138.20. Synonym.—Salt of Tartar. It should contain, when thoroughly dried, not less than 99 per cent. of Potassium Carbonate [CO (OK)2]. It contains not more than 15 per cent. of moisture. SOURCE. Pearlash, which is a product of the lixiviation of wood ashes, is treated with water, which dissolves little but Potassium Carbonate, and the solution is evaporated. CHARACTERS.-A white, granular powder, odorless, and having a very strong alkaline taste; very deliquescent. Solubility.-In 0.9 part of water and about 0.7 part of boiling water; insoluble in alcohol. IMPURITIES.-Nitrates, earthy matters, heavy metals. INCOMPATIBLES.-Acids; acid, alkaloidal, and most metallic salts, ethyl carbamate. The same incompatibles apply to the bicarbonate. Dose, 1 gm. (15 gr.). Potassium Carbonate is used in preparing Pilula Ferri Carbonatis (in which Ferrous Carbonate is formed), Spiritus Ætheris Nitrosi, Syrupus Rhei, and Syrupus Rhei Aromaticus. 3. POTASSII BICARBONAS.-Potassium Bicarbonate. Abv.-Pot. Bicarb. KHCO3 = 100.11. It should contain not less than 99 per cent. of Potassium Bicarbonate [CO(OH)(OK)]. SOURCE.-Pass Carbon Dioxide through a solution of Potassium Carbonate, and let the bicarbonate crystallize out. K2CO3+CO2+H2O=2KHCO3. CHARACTERS.-Colorless, transparent, monoclinic prisms, or as a white, granular powder, odorless, having a saline and slightly alkaline taste. Permanent in the air. Solubility. In about 2.8 parts of water at 25°C. (77°F.), and 2 parts at 50°C. (122°F.). At a higher temperature the solution rapidly loses Carbon Dioxide, and, after being boiled, contains only Potassium Carbonate. Almost insoluble in Alcohol. IMPURITIES. The carbonate and heavy metals. Potassium Bicarbonate is used in preparing Liquor Magnesii Citratis, Liquor Potassii Arsenitis, and Liquor Potassii Citratis. For the Therapeutics of Potassium Carbonate and Bicarbonate see p. 368. 4. POTASSII ACETAS.-Potassium Acetate. Abv. Pot. Acet. KC2H3O2 98.12. It should contain, when thoroughly dried, not less than 99 per cent. of Potassium Acetate. SOURCE. Add Acetic Acid in excess to Potassium Bicarbanate. Evaporate to dryness and fuse the residue. KHCO3+HC2H3O2 = KC2H3O2+H2O+CO2. CHARACTERS.-A white powder, or crystalline masses of a satin-like lustre, odorless, or with a faint, acetous odor, and having a warming, saline taste; very deliquescent on exposure to the air. Solubility.-In 0.4 part of water, and 2 parts of Alcohol; much more soluble in both liquids at high temperatures. IMPURITIES.-Arsenic, heavy metals. INCOMPATIBLES.-Mineral acids. These are incompatible with other acetates also. Dose, 1 gm. (15 gr.). 5. POTASSII CITRAS.—Potassium Citrate. Abv.-Pot. Cit. KзC6H5O7+ H2O=324.36. It should contain not less than 99 per cent. of Potassium Citrate [CзH(OH) (COOK)3+H2O]. SOURCE.-Neutralize Potassium Carbonate with a solution of Citric Acid, and evaporate to dryness. 3K,CO3+2H3C6H5O7=2K3C6H5O7+3H2O+3CO2. CHARACTERS.-Transparent, prismatic crystals, or a white, granular powder; odorless, and having a cooling, saline taste. Deliquescent on exposure to the air. Solubility.-In about 0.6 part of water; very soluble in boiling water; almost insoluble in Alcohol, freely soluble in glycerin. IMPURITIES. The tartrate and heavy metals. INCOMPATIBLES.-Alcohol, lead acetate, potassium permanganate in acid solution, silver nitrate. Dose, 1 gm. (15 gr.). Preparation Liquor Potassii Citratis.-Solution of Potassium Citrate. Abv.Liq. Pot. Cit. Citric Acid, 6; Potassium Bicarbonate, 8; water to 100. The acid and the bicarbonate are dissolved separately and the solutions mixed. It should contain not less than 8 per cent. of anhydrous Potassium Citrate [C3H4(OH) (COOK)3=306.34], with small amounts of Citric and Carbonic Acids. Dose, 16 mils (4 fl. dr.). 6. POTASSII CITRAS EFFERVESCENS.-Effervescent Potassium Citrate. Abv. Pot. Cit. Eff. Potassium Citrate, 200; Sodium Bicarbonate, 477; Tartaric Acid, 252; Citric Acid, 162. SOURCE.-The Citric Acid and Tartaric Acid, powdered, are mixed with the Potassium Citrate, after it has been dried and powdered; and the Sodium Bicarbonate is then thoroughly incorporated. The mixture is subjected to a high temperature in an oven, and when, by the aid of careful manipulation with a |