What is "naphthalene red"

Naphthalene \Naph"tha*lene\, n. (Chem.) A white crystalline aromatic hydrocarbon, C10H8, analogous to benzene, and obtained by the distillation of certain bituminous materials, such as the heavy oil of coal tar. It is the type and basis of a large number of derivatives among organic compounds. Formerly called also naphthaline.

Naphthalene red (Chem.), a dyestuff obtained from certain diazo derivatives of naphthylamine, and called also magdala red.

Naphthalene yellow (Chem.), a yellow dyestuff obtained from certain nitro derivatives of naphthol.