Pierre Joseph Pelletier (1788-1842), French chemist. Pelletier was born at Paris. He studied at the Ecole de Pharmacie and taught there until his retirement in 1842. From 1809 he and J.B. Caventou began extracting chemicals from plants by using mild solvents rather than the traditional method of destructive distillation. In 1817, they isolated chlorophyll, the green chemical used by plants in photosynthesis. They also discovered a number of other 'vegetable bases' (alkaloids) such as strychnine, caffeine, cinchonine and veratrine by the same process. In 1823, Pelletier proved that alkaloids contain nitrogen in a ring structure in work done with Dumas. In 1827 they isolated quinine, a discovery for which they won a 10, 000 Franc prize from the Paris Academy of Science. In 1838 Pelletier and Walter isolated the cyclic organic chemical toluene.