1905.] The Alcoholic Ferment of Yeast- Juice. 407 



water (Experiment 4, Table II). Further, yeast killed by acetone and ether 

 (Aceton-Dauerhefe) reacts with boiled juice in the same way as does yeast- 

 juice (Experiment 5, Table II). 



Table II. — Effect of Various Substances in Increasing Alcoholic 



Fermentation. 



No, 



Yeast- 

 j uice. 



Addition. 



Glucose. 



Time. 



Carbon 



el i nYi ft (* 



• It < > A 1 M > 





CO. 







hours. 



gramme. 



1 



25 





5 



48 



110 





25 



25 c.c. water + precipitate by 



5 



48 



'268 







. 75 per cent, alcohol from 25 c.c. 













boiled fresli juice 











OK 



Jo 



Filtrate from 25 c.c. boiled fresli 



5 



•IS 



U 141 







juice + 3 volumes alcohol, made 













to 25 c.c. 











25 



25 c.c. water + precipitate from 



5 



48 



0-286 







25 c.c. boiled old juice by 













75 per cent, alcohol 









2 



25 





5 



72 



0-070 





25 



25 c.c. autoplasmolysed yeast- 



5 ; 



72 



189 







juice, made neutral 









3 



25 





5 



72 



-084 





. 25 



25 c.c. autoplasmolysed yeast- 



5 



72 



-172 







juice, made neutral 











25 : 





5 



72 



0-475 



4 



25 



25 c.c. aqueous infusion of 



5 



72 



0-625 







2 grammes Aceton-Dauerhefe 









5 



2 grammes 





4 



48 



0-062 





Aceton- 













Dauerhefe 















20 c.c. water + 20 c.c. boiled juice 



4 



48 



136 



2. Dialysis of the Boiled Juice. 



The constituent of the boiled and filtered juice to which this effect is due 

 is removed when the liquid is dialysed in a parchment tube, leaving an 

 inactive residue. In the experiments detailed in the following table 

 (Table III, Experiments 1, 2 and 3) the effect of the addition of boiled juice 

 is compared with that produced by the residue and dialysate respectively. 



In Experiment 4, the unboiled juice was dialysed, and the fact that the 

 dialysate had a similar effect to a boiled juice shows that the active 

 constituent exists in the original yeast-juice and is not formed during the 

 boiling. 



