70 MICROBES, FERMENTS, AND MOULDS. 



tion in putrefying bodies which would not be rejected 

 by modern naturalists and chemists. 



"After death . . . the foreign ferments, which are 

 always intent on change, are borne through the air 

 and introduce corruption into dead matter ... at 

 least, unless the flesh is combined with certain sub- 

 stances, such as sugar, honey, or salt. It is, therefore, 

 these ferments, attacking whatever matter is deprived 

 of life, which disintegrate and prepare it to receive a 

 new soul (or fresh life)." 



Linnaeus, again, says that " a certain number of 

 diseases result from animated, invisible particles, which 

 are dispersed through the air. . . ." Boerhave, in 1693, 

 distinguished three kinds of fermentation: alcoholic, 

 acetous, and putrefactive. But we must come down 

 to the beginning of this century in order to find more 

 definite ideas respecting the organic nature of ferments. 



In 1813, a chemist called Astier asserted that 

 every kind of germ from which ferments proceed is 

 carried by the air ; that this ferment, of animal 

 nature, is alive, and is nourished at the expense of 

 the sugar, and hence results disturbance of the 

 equilibrium between the elements of sugar. 



Subsequently, in 1837, Cagnard de La Tour de- 

 clared yeast to be a collection of globules which are 

 multiplied by budding; and in the following year 

 Turpin described the yeast of beer as a vegetable, 

 microscopic organism, which he termed Tonda cere- 

 visicB (Fig. 35). 



