AGENTS PROMOTING WASTE. 65 



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

 fl. 3 i.-ij. ; D., tt| ij.-v. 



Acidum. Aceticiim Dilutum, dilute acetic acid, 

 containing six per cent, absolute acid and ninety- 

 four per cent, water. 



Acetinn, vinegar, an impure dilute acetic acid, 

 prepared b}' 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 ^vood or saw^dust; the con- 

 densed products separate into two layers — the lowxr 

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

 tion of p3^roligneous 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 w^ood, 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 

 w4ne, 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, 

 5 



