STUDIES ON FERMENTATION. 133 



tlie phosphorus of the phosphates, to form the albuminous sub- 

 stances of the interior of the cells.* In this case the sugar 

 used up would furnish no alcohol, or at least, if alcohol were 

 formed, it would be decomposed immediately. All aerial 

 growths take place in the same manner ; and such is the nature 

 of nutrition and life in all the larger forms. 



In our flasks, on the other hand, the life of the little plant 

 functions quite differently. Deprived of oxygen, or having at 

 its disposal but an insufficient quantity of that gas, after a life 

 of activity in contact with air, it can, nevertheless, live apart 

 from the direct action of that element, and the combinations to 

 which it gives rise. On the other hand, we see all the signs of 

 alcoholic fermentation appear ; that is, a notable proportion of 

 sugar, in comparison with the weight of solid matter assimi- 

 lated and fixed by the plant, is decomposed into alcohol and 

 carbonic acid gas ; and this decomposition continues as long as 

 life itself continues in the cells, and they remain submerged, 

 this last condition being effected by the decantation of the 

 liquid and its deposit into the test-glass. Along with the 

 disappearance of the phenomena of vital activity in the cells, 

 the fermentation ceases absolutely, or at least is no longer 

 visible externally, by reason of its extreme feebleness. The 

 cells then assume an old, shrivelled, worn-out appearance, with 

 irregular outlines and granular markings. Their life is merely 

 suspended, however, not extinct ; for if they be supplied once 

 more with oxygen, and suffered to exist under the influence of 

 that gas, they will vegetate again, and become capable of pro- 

 ducing fermentation afresh, even after having been excluded 

 from the air for a considerable time. 



Oxygen then presents itself to us as being endowed with a 

 certain determining stimulus in the matter of nutritive action 

 enabling this action to be prolonged beyond the point where 



* AVe do not here take into account certain phenomena of oxidation of 

 ■which the fungoid growths are the seat, and which remind us of those 

 that are presented m so remarkable a degree by mycoderma vini and 

 mycoderma aceti. 



