AGENTS PROMOTIKG WASTE. 65 



acid, and sixty-four per cent.- water. Dose: H., 

 fl. 3i.-ij.; D., m ij.-v. 



Acidum Aceticum Dilutum, dilute acetic acid, 

 containing six per cent, absolute acid and ninety- 

 four per cent, water. 



Acetum, vinegar, an impure dilute acetic acid, 

 prepared by acetous fermentation of wine, cider, or 

 other fruit juice. 



Pure acetic acid is a colorless, strongly acid liquid, 

 having a pungent odor, and is prepared by the de- 

 structive distillation of wood or sawdust; the con- 

 densed products separate into two layers — the lower 

 one wood-tar; the upper, a two- to four-per-cent. solu- 

 tion of pyroligneous or impure acetic acid, together 

 with wood alcohol, acetone, and other allied bodies. 

 Sodium carbonate is now added, the volatile hydro- 

 carbons distilled off, and the remaining liquid evapo- 

 rated down— which leaves sodium acetate. This in 

 turn is further decomposed by sulphuric acid, and 

 again distilled, thus forming acetic acid. Acetic acid 

 dissolves resins, camphor, volatile oils, and many al- 

 kaloids, and unites with bases to form acetates. Ace- 

 tum or vinegar may also be prepared by the destruc- 

 tive distillation of wood, but usually is obtained 

 from the oxidation of impure alcohols by exposing 

 them to the air at about 80° F. while in contact with 

 a ferment. For this purpose the poorer grades of 

 wine, also cider, are used. 



Physiological Action. — Acetic acid is corro- 

 sive, irritant, and vesicant, and is seldom used inter- 

 nally, except in combination. Externally, diluted, 

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