580 On the Probable Existence of Emulsin in Yeast. 
were obtained with a liquid containing 1 gramme of Merck’s emulsin 
thoroughly mixed with 100 c.c. of water :— 
Time required for decompo- 
sition of amygdalin by 
1 c.c. of the liquid 
after heating. 
Temperature 
to which liquid| Time of heating. 
was heated. 


degrees. hours. minutes. 
64. 2 30 
65 1 30 
66 1 40 
68 1 40 
69 1 90 
70 | 75 minutes 150 
TA | 300. 30 hours 
71 AD anes no action 
These results show that although the temperature at which emulsin 
becomes inactive is practically identical with that at which the activity of 
the glucosidolytic enzyme of yeast ceases, emulsin may be exposed to the 
same temperatures as yeast juice for a much longer time before its glucosido- 
lytic activity is destroyed. This is no doubt due to the fact that the concen- 
tration of the emulsin in the preparation used in this set of experiments 
was much greater than in the yeast juice used in the experiments described 
on p. 577. 
It has been shown, therefore, that the glucosides which are decomposed 
by yeast are those which are attacked by emulsin, and further that the 
conditions under which these decompositions are effected by yeast, especially 
as regards temperature, are those which are operative in the case of emulsin. 
Taking all these facts into consideration there seems to be little room for 
doubt that the glucosidolytic activity of yeast is due to the secretion of 
emulsin in the cells of the plant. 
