Manufacture: Dissolve purified oxalic acid 6.45 Gm., in distilled water q. s. 1,000 Ml. (Cc).

Properties and Uses. - Poisonous, reducing agent, decolorizes permanganate solutions, precipitates gold and platinum solutions, removes iron stains from linen, paper, fabrics. Acid potassium oxalates under names salt of sorrel, salt of lemon, are also much used in decolorizing tissues of various kinds. Owing to close resemblance of oxalic acid to Epsom salt, fatal poisonings have resulted from mistaking the former for the latter.

Poisoning: Have vomiting, burning pain, constriction of throat and stomach, collapse, drowsiness, stupor, dark-colored discharges, death. Empty stomach, then give powdered chalk, whiting, or wall-plaster in water, slaked lime (lime water), dried whitewash, to form insoluble oxalate, hot fomentations to loins, enema, oil, abundant water, opium.

3. Tribasic Fatty Acids.

(These acids have 3 hydrogen atoms replaceable by metals.)

Acidum Citricum. Citric Acid. - (Syn., Acid. Cit., Acidum Citri - Limonis - Limonum - Limonorum; Fr. Acide (du Citron) citrique; Ger. Acidum citricum, Citronensaure, Citronsaure.)

Fig. 468. - Oxalic acid crystal.

Manufacture: This tribasie organic acid occurs in juices of plants, especially in their fruit, as strawberry, raspberry, cherry, currant, Lemon, lime, gooseberry, whortleberry, cranberry, tamarind, tomato, etc.; it is usually prepared from the juice of limes or lemons by first clarifying by ebullition, neutralizing with chalk and washing the resulting calcium citrate with boiling water, in which it is sparingly soluble, decomposing with diluted sulphuric acid; strain out calcium sulphate, concentrate, allow to crystallize in wooden vats lined with lead: (1) 2H3C6H5O7 + 3CaCO3 = Ca3(C6H5O7)2 + 3CO2 + 3H2O. (2) Ca3(C6H6O7). + 3H2SO4 = 2H3C6H5O7 + 3CaSO4. It is in colorless, translucent, right-rhombic prisms, white powder; odorless; acid taste; efflorescent in warm air; soluble in water (.5), boiling water (.5), alcohol (1.8), ether (30); contains 99.5 p. c. of H3C6H5O7 + H2O. Tests: 1. Aqueous solution (1 in 10) acid, which, rendered alkaline by calcium hydroxide T. S., remains clear, but, on boiling, becomes opaque (calcium citrate). 2. Slowly ignited, decomposes without odor of burning sugar (dif. from tartaric acid). 3. Nearly neutralize aqueous solution (1 in 10) with ammonia water, + calcium sulphate T. S. - clear (abs. of oxalic acid); incinerate 2 Gm. - ash .05 p. c. Impurities: Heavy metals, lead, oxalic, sulphuric, tartaric acids. Dose, gr. 5-30 (.3-2 Gm.).

Preparations. - 1. Syrupus Acidi Citrici. Syrup of Citric Acid. (Syn., Syr. Acid. Cit.; Fr. Sirop (d'Acide citrique) de Limon; Ger. Citronsauresirup.)

Manufacture: 1 p. c. Dissolve citric acid 1 Gm. in distilled water 1 ML (Cc), add it to syrup 95 Ml. (Cc), mix well; add tincture of lemon peel 1 Ml. (Cc), shake, add syrup q. s. 100 Ml. (Cc), mix thoroughly. Should be kept in containers previously washed with boiling water, and not dispensed unless free from molds and fermentation products. Dose, 3j-4 (4-15 Ml. (Cc)).

2. Liquor Magnesii Citratis, 33 Gm. per bottle (350 Ml. (Cc)).

3. Effervescent Salts, 16.2-19.5-25 p. c, etc.

Properties and Uses. - Irritant, antiscorbutic, stimulant, diuretic, refrigerant; rheumatism, hemorrhage, jaundice, scurvy, fevers, antidote to alkaline and narcotic poisons, good locally for diphtheritic angina, gangrenous sore mouth, jaundice, pruritus, cancerous tumors, reduces obesity, prolonged usage emaciates.

Fig. 469. - Citric acid crystal.

Acidum Lacticum. Lactic Acid, HC3H5O3. - (Syn., Acid. Lact., Isolactic, Ethyledene-lactic, or Oxypropionic Acid; Fr. Acide lactique; Ger. Acidum lacticum, Milchsaure.) A liquid containing lactic acid and lactic anhydrides equivalent to 85-90 p. c. of HC3H5O3. This is the second member of a group of monobasic diatomic acids which contain two hydroxyl groups, the hydrogen in one (the upper, COH2) being replaceable by alcohol, that of the other (lower, CO2H) by metals:

Manufacture: Lactic acid occurs in gastric juice, urine, intestinal juices, many plant-juices, sour milk, sour cabbage, and is produced from sugar by the special lactic ferment (Bade'rium lac'tis). Allow milk sugar, or inverted sugar, milk, or cheese and water to undergo fermentation, at 25-35° C. (77-95° F.), neutralize acid as fast as formed with chalk or zinc oxide, as butyric acid will be produced if much free lactic acid present, recrystallize resulting calcium or zinc lactate, decompose with sulphuric acid or hydrogen sulphide, evaporate filtrate. It is a colorless, yellowish, syrupy liquid, nearly odorless, acid taste and reaction; absorbs moisture on exposure; miscible with water, alcohol, ether; insoluble in chloroform, petroleum benzin, carbon disulphide; sp. gr. 1.206; does not vaporize below 160° C. (320° F.), and at higher temperature emits inflammable vapors. Tests: 1. Add to 2 Ml. (Cc.) of equal volumes of lactic and sulphuric acids, potassium permanganate .1 Gm., heat gently - aldehyde odor. 2. Incinerate 5 Ml. (Cc.) - ash .006 Gm. Impurities: Heavy metals, chloride, sulphate, organic substances, sugars, citric, oxalic, phosphoric, sarcolactic, tartaric acids, glycerin. Dose, 3ss-2 (2-8 Ml. (Cc.)), in lemonade; if by enema, the acid should be neutralized by sodium bicarbonate.

Preparation. - 1. Syrupus Calcii Ladophosphatis, 6 p. c.

Properties and Uses. - Caustic, large doses hypnotic, stomachic. Lactic acid has gained its popularity from the fact of its being one of the constituents of the gastric juice, etc. Given in dyspepsia, phos-phatic deposits, tuberculous diarrhoea, green infantile diarrhoea, diabetes, rheumatism, otitis, ulcers of nasal fossae, diphtheria, croup, insomnia, caustic to fungous caries, lupus, epithelioma, ulcers, tuberculous ulcers, laryngeal and pharyngeal affections (morbid growths, etc.).