72 



THE BOTANICAL MAGAZINE. 



[Vol. XXXI. No. 303. 



Fig. 2. Curve showing the velocity of decomposition 

 of anthocyanin by oxidase. Abscissae, time in minutes; 

 ordinates concentration of anthocyanin (intensity of 

 colour). 



Table V. 



decolourization is 

 inversely ' propor- 

 tional to the 

 strenght of the en- 

 zyme solution to be 

 added to the equal 

 amount of hydro- 

 gen peroxide, and to 

 the concentration 

 of hydrogen per- 

 oxide to be added to 

 the equal amount 

 of the plant juice of 

 the same strength. 

 Catalase is also pre- 

 sent in the juice, 

 hence a portion of 

 oxygen is liberated 

 in a gaseous state. 

 To illustrate, the 

 following observa- 

 tion may be given : 



enzyme solul 

 added cc. 



ion relative 

 strength. 



H 2 2 (1:10) 

 added cc. 



anthocyanin 

 extract cc. 



intensity of col our 



(cone.) after 



1 br. 



2 



1 



1 



2 







2 



V« 



1 



2 







2 



V« 



1 



2 



26 



2 



Ve 



1 



2 



45 



2 



Vie 



1 



2 



82 



control 



(3 cc water) 



— 



2 



100 





As has already been mentioned, the decolourizing activity 

 of hydrogen peroxide and potassium permangnate is unhampered 

 by the presence of acid or alkali. A strongly acidified antho- 



