aichlorodiphenyl trichloro ethane or DDT

   Quite by chance, a 19th century Austrian Chemist, Othmar Ziedler, invented dichlorophenyl-tricloro-ethane or DDT, in 1874, But he ignored it since he could envision no practical value for it. it was not until 1939 that paul Muller of Switzerland observed its insecticidal properties. It was patented by the German company J.R. Geigy A-G in 1942 and within a few years became the most widely used unsecticide in the world.