Chem. [f. L. æscul-us a species of oak, in mod. Bot. applied to the horse-chestnut, + -IN, chem. form.] A glucoside contained in the bark of the horse-chestnut and allied trees; a crystalline fluorescent substance of composition C21H24O13.
1877. Watts, Fownes’ Chem., II. 604. The aqueous solution of æsculin is highly fluorescent, the reflected light being of a sky-blue colour.
