134 STUDIES ON FERMEKTATION. 



the direct influence of oxygen ceases. In time the energy that 

 has been imparted to the cells will die away, and then also 

 fermentation will cease, to be resumed, however, when the 

 plant is once more submitted to the revivifying action of the 

 gas. It seems as though the vital energy derived from the 

 influence of gaseous oxygen were capable of effecting an 

 assimilation of oxygen, not in the gaseous state, but existing 

 in some state of combination, and hence its power of causing the 

 decomposition of sugar. Looking at the matter in this light, 

 it seems to us that we may discover in it a fact of general 

 occurrence, that this peculiar action of the oxygen and the cells 

 is to be seen in all living beings. For indeed is there any cell 

 which, if suddenly and completely deprived of air, would perish 

 forthwith, and absolutely ? Probably there is not a single one 

 that would do so. With certain modifications of greater or 

 less amount the assimilative and excretive acts which have 

 taken place during life must be carried on after the suppression 

 of oxygen, resulting in fermentations ordinarily obscure and 

 feeble, but in the case of the cells of ferments, properly so 

 called, manifesting an activity both greater in amount and 

 more enduring. 



Let us now proceed to compare the weight of alcohol formed 

 by the mucor during fermentation with the weight of the plant 

 itself. 



Mrst experiment. — One of the double-necked flasks contained 

 at starting 120 c.c. (about 4 fl. oz.) of wort. 



On January 2nd, 1873, we attached this flask to a test-glass, 

 containing a deposit of mucor ferment (Fig. 19, p. 101), a 

 few drops of which we poured into the wort in the flask, to 

 impregnate it. On January 3rd we decanted the wort from 

 the flask into the test-glass ; under these conditions we have 

 seen that the wort must ferment. 



On January 18th the fermentation in the test-glass ceased. On 

 July 31st, 1873, we transferred the liquid from the test-glass 

 back to the flask. On August 4th, 1873, we again decanted 

 this same liquid from the flask into the test- glass. On December 



