HAIR DYES have been used since ancient times. There is evidence that the ancient Egyptians, Greeks, and Romans used them. The hair dyes used by the ancients were vegetable in origin. Nutgalls, saffron, thapsia,1 henna, indigo, camomile, sage tea, and many others were used for hair coloring. Dermatitis or systemic poisoning from hair dyes is not known to have occurred among the ancients; nevertheless, the ancient physicians were prejudiced against their use. This prejudice has persisted among physicians to the present. Metallic salts were also used as hair dyes as early as Galen's time. Lead salts were used for hair dyeing by the ancient Chinese. Occasional cases of metal poisoning were attributed to them, but neither the disapproval of physicians nor the hazard of poisoning from improper use of the dyes deterred people from employing them. Metallic salts alone or in combination with vegetable dyes in solution or