Salicylic acid and salicin (q.v.) share the properties common to the group of aromatic acids, which, as a group, are antiseptic without being toxic to man - a property practically unique; are unstable in the body; are antipyretic and analgesic; and diminish the excretion of urea by the kidneys.
When salicin is taken internally no irritant action occurs, nor is there any antisepsis.
A valuable medicinal glucoside named salicin (q.v.) is also extracted from the bark.