Lister for isolating a pure culture of lactic acid bacterium.
The lactic acid bacilli are given either in the form of tablets or milk soured by them, or cheese made from the sour milk.
When Pasteur in 1857 showed that the lactic fermentation depends on the presence of an organism, it was already known from the researches of Schwann (1837) and Helmholtz (1843) that fermentation and putrefaction are intimately connected with the presence of organisms derived from the air, and that the preservation of putrescible substances depends on this principle.
Pictet, Vegetable Opium also contains a gum, pectin, a wax, sugar and similar substances, in addition to meconic and lactic acids.
Although on structural grounds there should be only two hydroxypropionic acids, as a matter of fact four lactic acids are known.
