66 REACTION OF CELLS 



Now it ought to be observed that with increasing 

 time the effect tends to a limiting value, and this the 

 more rapidly the higher the temperature. Thus, for 

 instance, at 39 C. the values of ^ obSj for 60 minutes 

 and for 180 minutes are 001 9 and 0-015 respectively. 

 Instead of being in the proportion 3 to 1, these 

 figures are as 13 to 1. Below 30 C. the proportion 

 is, within the errors of experiment, as 2 to 1 for the 

 times of action 10 minutes and 20 minutes. In con- 

 sequence of this behaviour the //,-value seems to sink 

 with increasing time. The right value of \x is the 

 limit-value for the time of action o, which is found 

 by extrapolation from the values observed with 

 different times, z (z= 10, £ = 20, £=30, £ = 60, etc.). 

 It is about 29,000. For acetic, propionic, and 

 butyric acid we find in the same manner values lying 

 round about 26,000. The same figure is given by 

 vibriolysin. It seems as if weak acids or bases, and 

 lysins of bacterial origin give nearly the same value 

 for fi } for very short time of action. Strong acids 

 and bases give too low values of /^, probably because 

 their attack is too rapid. 



Sodium oleate behaves in quite a different manner. 

 Here ^ (10 minutes of action) does not reach a 

 value higher than 3800, so that the velocity of re- 

 action is only double as great at 36-3° C. as at 4 C. 

 Cobra poison acts nearly independently of the 

 temperature, and the poison of the water moccasin 

 seems to act 15 times more slowly even at 39° C. 

 than at n° C. These apparent anomalies seem to 

 merit a closer investigation. 



