Pyroligneous Acid (Gr.Pyroligneous Acid 140071 , fire, and Lat. lignum, wood), also called pyroligneous and wood vinegar, the compound mixture of the volatile products from the destructive distillation of woody matters, which when purified yield acetic acid, wood naphtha, creosote, tar, etc. The method of producing it is noticed in the article Acetic Acid, vol. i., p. 62, as also its use in the crude state for furnishing compounds useful as mordants in calico print works, as pyrolignate of iron, alumina, etc. It has been applied to various other uses, as for example, in medicine, as an antiseptic and stimulant in a wash for gangrene and ulcers, although at present the more definite products, such as carbolic acid, are preferred. Its antiseptic qualities have led to its use in preserving articles of food, as herrings and other fish. The process is auxiliary to drying in the shade, which precedes the dipping of the articles in the acid. Herrings first cured by a sprinkling of salt left upon them for six hours, and then drained, being immersed a few seconds in pyroligneous acid and then dried for two months, are in an excellent condition for preservation and retain a smoky flavor.

The addition of a quart of the acid to the common pickle for a barrel of hams will cause the hams to acquire this flavor as if they had been smoked in the ordinary way.