78 FERMENTATION. 



formed ferment. But they went too far, in asserting 

 that fermentation was a necessary condition of the 

 origin or formation of such cells. 



Blondeau, in 1847, was still of opinion that fer- 

 mentation preceded the formation of ferment plants, 

 and that it was developed step by step with them. 



Two kinds of these plants are found in the yeast of 

 beer, Torvula ceremsicB and Penicillium Glaucum. 

 The first are the genuine globules of ferment, the lat- 

 ter is a white film, such as may be seen in other sub- 

 stances verging on putrefaction ; it is of a tube shape, 

 with ramifications, and Blondeau can only have seen 

 it in ferment which had been spoiled. 



That fermentation is very much determined by the 

 quality of these cells was what Liidersdorff attempted 

 to show, by proving that the cells of ferment, after 

 being rubbed in water for six hours, are incapable of 

 producing fermentation.* But Schmidt has rightly 

 observed,f that so much friction would considerably 

 facilitate the oxidation of the fermenting matter. 

 LiidersdorfFs experiment and its negative result only 

 serve to establish the assertion laid down (p. 64), 

 " that the cause of fermentation is to be found in the 

 oxidation or decomposition of the contents of the fer- 

 ment cells." Schmidt found in a single gramme 

 (15'4 grs.) of ferment (after it had been in contact 

 with water for six hours), by adding sulphate of mag- 

 nesia and phosphate of soda to the liquid, and collect- 



* Fogg's Ann. Bd. 67, s. 409. t Liebig's Ann. Bd. 61, s. 171. 



