Nobel Prize Recipient. Paul Müller, a Swiss chemist, received recognition after being awarded the 1948 Nobel Prize in Physiology or Medicine. He received the coveted award for, according to the Nobel Prize committee, "for his discovery of the high efficiency of DDT as a contact poison against several arthropods." In 1942 Müller discovered that the substance DDT or dichloro-diphenyl-trichloroethane was an effective insecticide. DDT halted the spread of malaria, typhus, yellow fever, and other diseases that were causing deadly epidemics world-wide to the human population. The United States Environmental Protection Agency issued a cancellation order in 1972 for DDT based on its adverse environmental effects, such as those to wildlife, as well as its potential human health risks. Born Paul Hermann Muller, the oldest of four children, he was the son of an employee of the Swiss Federal Railway. He was called "Pauly" his entire life. As a child, he had his own laboratory "inventing" things. He attended local schools with no plans for college. In 1916 he left school to accept a position as a laboratory assistant at Dreyfus and Company, and the following year he joined Lonza A.G. as an assistant chemist in the Scientific-Industrial Laboratory of their electrical plant. In these positions, he gained a wealth of hands-on experience, which would later help him in his career as an industrial chemist. He matriculated in 1918 and returned to school to obtain his diploma in 1919, which entitled him to attend Basle University. He majored in chemistry but had a minor in botany and physics. Graduating summa cum laude, he received his doctorate degree in 1925, and in May of that year, he began his career with J. R. Geigy A.G., eventually becoming Deputy Director of Scientific Research on Substances for Plant Protection in 1946. His early research involved vegetable dyes, natural tanning agents and disinfectants. Changing his interest, he began research for a moth-proofing agent for textiles, on pesticides in general, and he developed Graminone, a mercury-free seed disinfectant. In 1935, he started his researches on new synthetic contact insecticides, discovering DDT and patenting the substance in 1940. Closely related to DDT, Gesarol and Neocide, were marketed in 1942. During World War II, DDT eradicated malaria from the Pacific island areas in 1943, saving the lives of thousands of United States military. He was a prolific writer and his scientific papers were published in "Helvetica Chimica Acta". In 1961 Müller retired from the Geigy Company and established a private laboratory at his home in Oberswil, where he continued his investigations until his death. Besides the Nobel Prize, he received honorary doctorate degrees from universities around the world, in 1963 the Golden medal of the city of Thessanloniki in Greece, and the Medal of Honour from Paris, France in 1952. He married and the couple had two sons and a daughter.