Ultraviolet quickly than violet light itself. He called them "oxidizing rays" to emphasize chemical reactivity and to distinguish them from "heat rays", discovered the previous year at the other end of the visible spectrum. The simpler term "chemical rays" was adopted shortly thereafter, and it remained popular throughout the 19th century, although there were those who held that these were an entirely different sort of radiation from light (notably John William Draper, who named them "tithonic rays"). The terms chemical rays and heat rays were eventually dropped in favor of ultraviolet and infrared radiation, respectively. In 1878 the sterilizing effect of
Ultraviolet communication in butterflies communicate their receptivity to males using their ultraviolet communication system. The ultraviolet reflection is thought to be concentrated to the ventral side of a female’s hind wing. Yoshiaki Obara determined this experimentally by comparing the number of approaches to different parts of butterfly wings. The results showed that the female’s ventral hind wing was the greatest releaser of male sexual behavior. Although ultraviolet reflectance releases the sexual behavior, the strongest reflection of UV light is not the strongest releaser for the behavior. As a result, male white cabbage butterflies must have a preference for a certain level of UV reflectance