VELOCITY OF REACTION. HETEROGENEOUS SYSTEMS 143 



origin (streptolysin, //. = 31,900; vibriolysin, /-t = 27,300 ; for 

 tetanolysin the time of reaction has been too long to yield 

 correct value for /A). Close to these values are the highest 

 ones of those for the haemolytic action of acids and bases 

 (ammonia, ^ = 27,000; propionic acid, ^ = 25,000). The 

 values of p for these substances have already been dis- 

 cussed at length above. 



For comparison I tabulate the other values of JJL given in 

 this chapter : 



Digestion of powdered casein by means of trypsin ..../*= 7,400 

 Saponification of emulsion of yolk by means of pancreatic juice /* = 13,600 



Respiration of different plants (mean value) p = 14,800 



Production of alcohol by means of yeast-cell /* = 15,600 



Assimilation process in plants /A = 12,000 



Cell-division in different eggs (mean value) jx 14,100 



Heart-beats of the Pacific terrapin /A = 16,060 



The p values are in general of the same order of mag- 

 nitude as in the case of homogeneous reactions. The 

 great similarity of the values of n for the different life- 

 processes would scarcely seem to be accidental. 



COLLEGE OF DENTISTRY 

 UNIVERSITY OF CALIFORNIA 



