A thick black liquid, obtained during the distillation of coal for the manufacture of illuminating gas. This substance yields madder, a coloring substance formerly obtained from the roots of a plant. One ton of cannel coal when distilled leaves 12 gallons of coal-tar, from which are produced 1 lb. of benzene, 11/2 lb. of carbolic/ acid, and a number of other substances used for dyeing purposes. From these substances there may be obtained 16 distinct yellow colors, 12 orange, 30 red, 15 blue, 7 green, 9 violet, besides a number of browns, and an indefinite number of blendings.