(a.) Pertaining to, derived from, or designating, an acid formerly obtained by fusing salicin with potassium hydroxide, and now made in large quantities from phenol (carbolic acid) by the action of carbon dioxide on heated sodium phenolate. It is a white crystalline substance. It is used as an antiseptic, and in its salts in the treatment of rheumatism. Called also hydroxybenzoic acid.