Germ Theory |
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Law of Ferments
1857

Claimed specific ferments as cause of particular fermentations.
Louis Pasteur - Paper on Lactic Fermentation
1857
Pasteur presents a paper on lactic fermentation to the Académie des sciences.

Pasteur's Idea
1859
Expressed the opinion that the causes of contagious diseases are similar to those of fermentation.
Louis Pasteur disproves spontaneous generation
1861

Pasteur conducts his famous germ theory experiment which disproved spontaneous generation.
Pasteur argued that if spontaneous generation had been a real phenomenon, the broth in the curved-neck flask would have eventually become reinfected because the germs would have spontaneously generated. But the curved-neck flask never became infected, indicating that the germs could only come from other germs.

Pasteur’s drawings of the flasks he used (Pasteur, 1861). Fig. 25 D, C, and B (top) show various sealed flasks (negative controls); Fig. 26 (bottom right) illustrates a straight-necked flask directly open to the atmosphere (positive control); and Fig. 25 A (bottom left) illustrates the specially designed swan-necked flask (treatment group).
Louis Pasteur discovers anaerobic (oxygen-deprived) life
1861
From his report: “This is, I believe, the first known example of animal ferments, and also of animals living without free oxygen gas. The comparison of the way of life and properties of these animalcules with the way of life and properties of the vegetable ferments who live equally without the aid of free oxygen, is selfevident, along with the consequences that may be deduced from it relating to the cause of fermentations.”
