iQig] 



ROSE— BLISTER CANKER 



"5 



\|CC^1) ACETJC Arm TO 1 CC"^^ SOD, ACRTATF. 

 ^10.24 5.12 2.56 1.28 0. 0.32 Q.I6 0.08 0.04 



Fig. 2.— Pjj of mixtures of bark, pyrogallol, and various buffer solutions before 

 and after oxidation had ceased: A, P^ of buffer solutions; B, Pjj of mixtures of 

 buffer solutions, pyrogallol, and diseased bark before oxidation; C, P^ of mixtures 

 of buffer solutions, pyrogallol, and healthy bark before oxidation; D, P^ of mixtures 

 of buffer solutions, pyrogallol, and diseased bark after oxidation; E, Pjj of mixtures 

 of buffer solutions, pyrogallol, and healthy bark after oxidation. *Onry acetic acid 

 used here. 



