Louis Pasteur

Louis Pasteur (1822–1895) was a French chemist and microbiologist whose discoveries established the germ theory of disease and transformed medicine, food safety and public health. He began as a chemist, discovering molecular chirality through his study of tartaric acid crystals, before a request from local industry led him to study fermentation. He showed that fermentation and spoilage are caused by living microorganisms, and he developed pasteurization, the gentle heating process that still protects milk and other foods. His swan-neck flask experiments helped disprove the idea of spontaneous generation. Turning to disease, he developed vaccines against chicken cholera and anthrax, and in 1885 successfully treated a boy bitten by a rabid dog with his new rabies vaccine. The Pasteur Institute, founded in Paris in 1887, continues his work in research and the prevention of infectious disease.