Pasteur Proves Germ Theory — Founding of Microbiology
Before Pasteur, the dominant theory held that disease arose from 'miasma' (bad air) or spontaneous generation. Pasteur, a chemist investigating wine fermentation, proved by 1857 that fermentation was caused by living microorganisms, not a chemical reaction. His famous swan-neck flask experiments (1859–61) refuted spontaneous generation: broth in flasks with curved necks remained sterile indefinitely unless the necks were broken, allowing airborne microbes to enter. He went on to demonstrate that specific microorganisms caused specific diseases (anthrax, chicken cholera, rabies) and developed vaccines for chicken cholera (1880), anthrax (1881), and rabies (1885). His near-contemporary Robert Koch identified the specific bacteria responsible for tuberculosis (1882) and cholera (1883), and developed Koch's postulates — the criteria for establishing that a specific microorganism causes a specific disease. Together, Pasteur and Koch founded bacteriology and microbiology. The immediate practical applications — antiseptic surgery (Lister), pasteurisation, vaccines — represented the greatest reduction in human mortality in history.
- Year: 1861 CE
- Category: Scientific
