Preparations. - 1. Oleatum Hydrargyri, 75 p. c.

Unoff. Preps.: Oleates of Aconitine (50), Atropine (50), Cocaine (50), Quinine (75), Veratrine (50), etc.

Properties and Uses. - Important, since it is a solvent for medicines to be applied by inunction and the base of official oleates, which do not decompose (becoming rancid, etc.) like ointments, and enter the skin deeper without irritation. Oleate of Mercury - good in skin diseases (sycosis, chloasma, pediculi), syphilitic affections, thinning and loss of hair; oleates of atropine, cocaine quinine, veratrine, zinc, and some other unofficial oleates are very useful.

Acidum Stearicum. Stearic Acid, HC18H35O2. - (Syn., Acid. Stear., Acidum Stearinicum; Fr. Acide stearique; Ger. Stearinsaure.) An acid obtained from tallow and other solid fats, consisting chiefly of HC18H35O2.

Manufacture: This exists as the glyceride in all solid animal fats and in many oils, and is prepared from tallow by boiling with NaOH or K2CO3; this forms sodium stearate (soap) and liberates glycerin - C3H5(C18H35O2)3 + 3NaOH = C3H5(OH)3 + 3NaC18H35O2. The soap is decomposed by heating with water and H2SO4 (or HC1), thus setting free the fatty acids, which, floating on the surface, are removed; upon cooling, the solid acid mixture is subjected to strong pressure, thereby removing the fluid acids, oleic, etc. It is a hard, white, yellowish, glossy solid, odorless, slight tallow-like odor, tasteless, permanent, soluble in alcohol (21), chloroform (2), ether (3), freely in carbon disulphide, carbon tetrachloride, almost insoluble in water; melts at 56° C. (133° F.); congeals at 54° C. (129° P.); incinerate 1 Gm. - residue .1 p. c. Tests: 1. Boil 1 Gm. + monohydrated sodium carbonate .5 Gm. + distilled water 30 Ml. (Cc.) in capacious flask - hot solution not more than opalescent (abs. of undecomposed fat, paraffin). 2. Melt, shake with hot distilled water (1); separated water after filtration, + a drop of methyl orange T. S. - not reddened (abs. of mineral acids). Impurities: Undecomposed fat, paraffin, mineral acids.

Preparation. - 1. Suppositoria Glycerini, each 3 gr. (.2 Gm.). Properties and Uses. - Mainly in manufacturing glycerin suppositories, and as zinc and copper stearates, for various skin diseases.

2. Dibasic Fatty Acids.

(These have 2 hydrogen atoms replaceable by metals.)

Acidum Tartaricum. Tartaric Acid. - (Syn., Acid. Tart., Sal Essen-tiali Tartari, Dioxysuccinic Acid; Fr. Acide du Tartre - tartrique; Ger. Acidum tartaricum, Weinsaure, Weinsteinsaure.) A dibasic organic acid, usually obtained from wine lees or argol, containing 99.5 p. c. of H2C4H4O6.

I Fatty Series 951

Manufacture: Tartaric acid is found in vegetables and fruits, free and combined with potassium or calcium. The grape contains most, having it in the form of potassium acid tartrate, crude tartar, or argol. This substance is soluble in an aqueous saccharine solution, as of fresh grape juice; but when the weak saccharine solution begins to ferment alcohol is formed, in which argol is not soluble, consequently it is precipitated. Although argol is principally potassium acid tartrate, it also contains some calcium, magnesium, iron and aluminum salts. It is dissolved in water at 140-170° C. (284-338° F.) under pressure, clear solution not quite neutralized with chalk, adding only until effervescence nearly ceases, in order to retain in solution the magnesium, iron and aluminum salts - 2KHC4H4O6 + CaCO3 = CaC4H4O6 + K2C4H4O6 + CO2 + H2O; calcium chloride is now added to the hot mixture to convert remaining soluble normal potassium tartrate into insoluble calcium tartrate - K2C4H4O6 + CaCl2 = CaC4H4O6 + 2KC1; the resulting calcium tartrate is washed and heated with diluted sulphuric acid at 75° C. (167° F.); the solution of free acid is evaporated in lead vacuum pans and allowed to crystallize in lead-lined vats - CaC4H4O6 + H2SO4 = H2C4H4O6 + CaSO4. It is in colorless, translucent, monoclinic prisms, white granular or fine powder; odorless; acid taste and reaction; permanent; soluble in water (.75), boiling water (.5), alcohol (3.3), slightly in ether, almost insoluble in chloroform. Tests: 1. Aqueous solution (1 in 2), + equal volume aqueous solution of potassium acetate (1 in 3) - white, crystalline precipitate, soluble in solution of alkalies, mineral acids, but insoluble in acetic

Fig. 467.   Tartaric acid crystal.

Fig. 467. - Tartaric acid crystal.

acid. 2. Ignited - gradually decomposes with odor of burning sugar; incinerate 2 Gm. - ash .05 p. c. Impurities: Heavy metals, lead, sulphuric, oxalic acids. Dose, gr. 5-30 (.3-2 Gm.). Preparations. - 1. Effervescent Salts, 25.2 p. c, etc. Properties and Uses. - Owing to its greater cheapness is much used in place of citric acid in making lemonade, effervescing drinks, powders, etc. When mixed with sugar, mucilage, aromatics, etc., it serves to moisten the throat in pharyngitis, pulmonary catarrh, to dissolve false membranes of diphtheria, correct fetor of feet, etc. Related Acid:

1. Acidum Oxalicum. Oxalic Acid, H2C 2O4,2H2O, official 1870-1880. - Obtained by oxidizing many organic substances (fats, sugars, starch, etc.) with nitric acid or other strong oxidizing agents; also on large scale by heating sawdust with KOH and NaOH at 250° C. (482° F.) to form oxalates, adding calcium hydroxide to alkaline oxalate solution to produce insoluble calcium oxalate, decomposing this with sulphuric or hydrochloric acid; found natively in many plants (Oxalis, Rumex, Rheum, and other genera) as acid calcium or potassium oxalate, also in urine as calcium oxalate. It is in large, transparent, colorless crystals, soluble in water, alcohol, heated highly splits into H2O,CO2,CO - very poisonous.

Preparation. - 1. Tenth-normal Oxalic Acid Volumetric Solution.