Benzoic acid (C₆H₆COOH)
The acid juice of apples and various other fruits was employed for preparing different medicines before any attempt was made to isolate the acid itself. Free benzoic acid, however, obtained by subliming benzoin, was discovered and minutely discussed by the French physician, Blaise de Vigenial (1522-96) toward the end of the sixteenth century. Benzoic acid was discovered in gum benzoin in 1608 and prepared from urine by Sholle in 1785. Its composition was established by Liebig and Wohler's classical research in 1832. In 1832 Wohler discovered the relationship between benzoic acid and hippuric acid, and in 1832, Liebig and Wohler determined the true composition of benzoic acid and established its relation to the other benzoyl compounds.