On this day 126 years ago, on January 12, 1899 (December 1, 1898 lunar calendar), the Swiss chemist Paul Hermann Müller was born. Paul Hermann Müller (born January 12, 1899 in Oltan, Canton of Solothurn, Switzerland, and died December 12, 1965 in Basel) was a Swiss chemist. In the autumn of 1939, he discovered the insecticidal properties of DDT, for which he was awarded the Nobel Prize in Physiology or Medicine in 1948. This was the first time that a non-physiologist had won this honor. Müller's father was a commercial employee of the Swiss Federal Railways. They lived in Landsborg in the canton of Aargau when he was young, and later they moved to Basel. Müller attended primary and secondary school here. Due to his poor grades, he failed to attend university at first, but instead worked as a chemical experimenter for two years, during which time he worked at the Lonza company. From 1918 to 1919 he entered secondary school again and passed the examination to go to university. From 1919 he studied at the University of Basel, majoring in chemistry and subspecializing in physics and botany. In 1925 he received his doctorate with honors. The title of his doctoral thesis was "Chemical and electronic chemical oxidation of as.m-dimethylenediamine and its mono- and dimethyl derivatives". From May 25, 1925 Müller began working as a research chemist at the Gaggi company in Basel. His research began with plants and artificial dyes, then he turned to artificial tanning agents. It was only in 1935 that Gagi began to study textile protectants and pesticides. Müller developed a mercury-free seed mold release agent. In the fall of 1939 he recognized the insecticidal effects of DDT. In 1948 Müller won the Nobel Prize in Physiology or Medicine for "discovery of the strong effects of DDT on arthropods as a contact toxin." Müller worked at Gagi until his retirement in 1961, where he was vice president from 1946. Müller married in 1927 and had two sons and a daughter. Comments: DDT still played an important role at the time, although it was later banned