First demonstration of the connection between a specific fermentation and the activity of a specific living micro-organism. This paper is often considered the beginning of bacteriology as a modern science. The above work is a very much abridged “Extrait par l’auteur” of the complete text of Pasteur’s full paper which underwent roughly simultaneous publication in Mémoires de la Société des Sciences, de l’Agriculture et des Arts de Lille, 2e sér., 1858, 5, 13-26, and in Ann. de Chim. et de Phys., 3e sér., 1858, 52, 408-18.