Stories We Like: A Guide to the Comma
benzidine ben·zi·dine (běn'zĭ-dēn')
A yellowish, white, or reddish-gray crystalline powder used in dyes and to detect blood.
an organic chemical belonging to the class of amines and used in making numerous dyestuffs. The azo dyes derived from benzidine are important because, unlike simpler classes of azo dyes, they become strongly fixed to cotton without a mordant.