During the destructive distillation of wood, an impure acid distils over; carbonate of soda is added to the distillate, and an acetate of soda formed, which is purified and distilled with sulphuric acid.


A colorless liquid of pungent odor and taste: sp. gr. 1.044. It is volatile and, on evaporation, should leave no residue. Contains 28 per cent. of anhydrous acid.