STUDIES ON FERMENTATION. 255 



of a few hours. The microscope still more clearly shows this 

 activity in the rapidity of budding, and the fresh and active 

 appearance of all the cells. Fig. 64 represents the yeast of 

 our last experiment at the moment when we stopped the 

 fermentation. Nothing has been taken from imagination, all 

 the groups have been faithfully sketched as they were.* 



In passing it is of interest to note how promptly the preced- 

 ing results were turned to good account practically. In well- 

 managed distilleries, the custom of aerating the wort and the 

 juices, to render them more adapted to fermentation, has been 

 introduced. The molasses, mixed with water, is permitted to 

 run in thin threads through the air at the moment when the 

 yeast is added. Manufactories have been erected, in which the 

 manufacture of yeast is almost exclusively carried on. The 

 saccharine worts, after the addition of yeast, are left to them- 

 selves, in contact with air, in shallow vats of large superficial 

 area, realizing thus on an immense scale the conditions of the 

 experiments which we undertook in 1861, and which we have 

 already described in determining the rapid and eas}^ multiplica- 

 tion of yeast in contact with air. 



The next experiment attempted was to determine the volume 

 of oxygen absorbed by a known quantity of yeast, the yeast 

 living in contact with air, and under such conditions that the 

 absorption of air was comparatively easy and abundant. 



With this object we repeated the experiment that we 

 performed with the large-bottomed flask (Fig. 62), employing 



Tig. 65. 



a vessel shaped like Fig. B. (Fig. 65), which is, in point of 



* This figure is on a scale of 300 diameters, most of the figures in this 

 work being of 400 diameters. 



