Paul Müller was an industrial chemist who discovered that dichlorodiphenyltrichloroethane (DDT) could be used as an insecticide. This was the first insecticide that could actually target insects; in small doses it was not toxic to humans and yet it was stable enough to remain effective over a period of months. When DDT was introduced in 1942, the effects it would have on the environment were not well understood. It was widely hailed, in particular for its ability to reduce the incidence of typhus, malaria, and a number of tropical diseases by reducing insect populations. Although the dangers of DDT use eventually prohibited its further general use, the World Health Organization estimates that approximately 25 million human lives were saved by the discovery and use of DDT. For his work with DDT and the role his discovery played in the fight against diseases such as typhus and malaria, M...