On Expressed Yeast-cell Plasma (Buchner's " Zymase "). 259 



for each set of experiments. The results, as a whole, show that more 

 carbon dioxide is given off from cane-sugar than from either of the 

 other sugars. 



FIG. 3. Showing the influence of different concentrations of sugar on gas 



evolved. 



:I 



3-0 



'hO 



a. 



a' 



10 



15 



25 



20 

 tf~sug&r. 



a, After 46 hours (uncorrected) ; a', corrected for &u Co- ferm. 

 6, 24 " " ; b , " " " 



Influence of Temperature. We made several experiments to ascertain 

 the most favourable temperature for the action of the juice. As an 

 example of the results obtained, we may quote the following : 



The juice was mixed with 10 per cent, of cane-sugar in the usual 

 way, and there were obtained 



At C.... 0'41 gramme of carbon dioxide in 48 hours. 



10 0-83 



5> 2o 1 '05 ,, ,, ,, 



37 1-17 



55 ' 1 II ,, 



The higher temperatures therefore appear to increase the activity of 

 the juice. 



Influence of Filtration. In order to ascertain what influence, if any, 

 nitration through Chamberland and Berkefeld niters had on the 

 activity of the juice, we carried out a series of experiments with 

 different juices, carefully testing their gas-producing activity before 

 and after filtration. Thymol was used as an antiseptic in each case 

 The results are given in Table III, and it will be seen that filtration 

 decreases to a considerable extent, but without entirely destroying, 

 both the auto-fermentation and the action of the juice on sugar. This 

 decrease in gas-evolving power is accompanied by a very considerable 



U 2 



