Paul Hermann Muller. Portrait of Paul Hermann Muller (1899-1965), Swiss chemist and the pioneer of DDT (DichloroDiphenylTrichloroethane) insect- icide. From 1935 Muller tried to find a chemical that could be used to kill insects without damaging other animals. In 1940 he patented DDT, which had been first made in 1873, as an insecticide. It was cheap, easy to produce and highly effective. It was used to kill the insect carriers of malaria, yellow fever and typhus, and for this he was awarded the 1948 Nobel Prize for Medicine. DDT began to fall out of use during the 1970s as insects became resistant to it and the chemical's effect on other animals was noted.