Indigo tine

CH. NO. Indigo blue; dark blue crystalline substance with a coppery tinge, which constitutes the coloring matter of indigo; prepared by treating indigo with lime and zinc-dust, which di olve it in the form of indigo white, and by oxidizing the solution of indigo white; exceedingly insoluble in all ordinary solvents, and therefore very fast when formed upon a fiber. See ARTIFICIAL INDIGO. The