Louis Pasteur (1822-1895), French microbiologist. Pasteur found that fermentation is caused by micro-organisms, and also proposed the germ theory of disease. He developed a vaccine against rabies, which led to the founding of the Pasteur Institute in 1888. He saved the French silkworm industry by identifying diseases that were decimating the worms. He discovered the anthrax bacterium and developed a vaccine against it. He also discovered that gentle heating of wine and beer preserves them from souring: the process of pasteurisation which is now widely used in the food industry. This photograph is from the Bain News Service, one of the USA's earliest news picture libraries. The photographs date from the 1890s to the 1930s.