318 STUDIES ON FERMENTATION. 



of suffar undergoing: fermentation, the number of cells is 

 capable of any increase." 



Notwithstanding Liebig's belief to the contrary, the idea 

 that the decomposition of sugar during fermentation is inti- 

 mately connected with a development of the cellules of the 

 ferment, or a prolongation of the life of cellules already formed, 

 is in no way opposed to the fact that the ferment is capable of 

 bringing about the fermentation of a pure solution of sugar. 

 It is manifest to any one who has studied such fermentation 

 with the microscope, even in those cases where the sweetened 

 water has been absolutely pure, that ferment-cells do multiply, 

 the reason being that \kiQ cells carry with them all the food- 

 supplies necessary for the life of the ferment. They may be 

 observed budding, at least many of them, and there can be no 

 doubt that those which do not bud still continue to live ; life 

 has other ways of manifesting itself besides development and 

 cell-proliferation. 



If we refer to the figures on page 81 of our Memoir of 1860, 

 Experiments D, E, F, G, H, I, we shall see that the weight of 

 yeast, in the case of the fermentation of a pure solution of 

 sugar, undergoes a considerable increase, even without taking 

 into account the fact that the sugared water gains from the 

 yeast certain soluble parts, since, in the experiments just 

 mentioned, the weights of solid yeast, washed and dried at 

 100° C. (212° F.), are much greater than those of the raw yeast 

 employed, dried at the same temperature. 



In these experiments we employed the following weights of 

 yeast, expressed in grammes (1 gramme = 15'43 grains) — 



2-313 

 2-626 

 1-198 

 0-G99 

 0-326 

 0-476 



which became after fermentation, we repeat, without taking 



