362 



STUDIES OlS^ FERMENTATION. 



3. The ratio between the quantities of oxygen held in solu- 

 tion in water and those held in solution in wort increases with 

 the concentration of the wort. By evaporating the same wort 

 to diiferent degrees of concentration, and afterwards saturating 

 it with air, at the same temperature, we obtained the following 

 figures for the ratio in question : — 



4. "Worts of different origin, but of the same density and 

 temperature, when saturated with oxygen, always contain very 

 nearly the same quantity of that gas. 



Two portions of the same wort, shaken up with air, one being 

 hot the other cold, then left to themselves for some time, and 

 afterwards saturated with air, at the same temperature, gave 

 the figures 1*22 for the ratio between the oxygen in the water 

 and that in the wort. 



Different worts of the same density, saturated at a tempe- 

 rature of 15° C. (59° F.), gave the following ratios : — 



"Wort kept in a bottle with air for 19 months 1-140 



Wort recently prepared . . . . . . 1'142 



"Wort kept in a bottle without air for 20 



months, aerated for 18 days . . . . 1'142 



"Wort evaporated to dryness and made up with 



water. . . . . . . . . . . . ri26 



5. The solubility of oxygen in wort differs very little from 

 the solubilit}'- of oxygen in sweetened water of the same 

 density. 



An experiment was made with a solution of sugar on the 

 one hand, and with wort more or less diluted with water on the 



I 



