The active chemical constituent of aspirin.
The acid and its salts (salicylates) occur
naturally in many plants; concentrated
sources include willow bark and oil of
wintergreen. When purified, salicylic acid is
a white solid, C6H4(OH)(COOH), which
crystallizes into prismatic needles at 159
degrees C. It is used as an antiseptic, in
food preparation, dyestuffs, and in the
preparation of aspirin.