1913.] Processes Operative in Solutions and Enzyme Action. 583 





Percentage 



hydrolysed 



Little enzyme 



Much enzyme 





28-3 



88 -8 85 





20 -8 



78 -7 77 





23 5 



84 -0 80 





Glucose obtained 





gnu. 



M/10 salicin alone 



0-388 





0-385 





-368 



„ +2M/5 „ 



0-364 



„ +4M/5 „ 



0-331 





0-450 



M/10 salicin 



1 -52 





1 -50 



„ +M/5 „ 



1 -44 



It will be noticed that both glucose and saligenin have the greater effect 

 when the amount of enzyme present is small. It is very noteworthy that 

 saligenin has so marked an effect : but both salicin and saligenin are 

 slightly soluble substances and it is to be expected therefore that the 

 former would be specially sensitive. We do not regard the influence on 

 the activity of emulsin exercised by saligenin as in any way a case of 

 preferential retardation by a compatible material — both on general grounds 

 and because it has so marked an influence both on a-glucase and on urease. 



The influence of the small quantities of alcohol produced during hydrolysis 

 is subordinate, although at a higher concentration the alcohol soon exercises 

 a marked influence. The following tables show the magnitude of this 

 effect : — 



M/10 a-Methyl Glucoside + Yeast Extract. 



Medium 



Relative change 



Medium 



Relative change 



Water 





90 



Water 



91 



10 p. c. 



ethylic alcohol ... 



44 



10 p. c. niethvlic alcohol... 



51 



20 



)> ;) 



25 



20 „ „ ... 



21 



40 



J) 3> 



10 



<«> ,j „ 







60 



» )) 



2 



60 „ ' „ ... 







Methylic alcohol is apparently more toxic than the higher homologue. 



