MECHANISM OF DEATH 



281 



computation of i^ in Table 79 shows that it fluctuates 

 around the average value of K. In the experiments 

 with mustard seeds (Table 77), the death rate is com- 

 puted by the same formula; it is not constant, however, 

 but increases continuously. This is sufficient evidence 

 that the death follows a different law. 



3,0 



% 

 t 



4^ 



2.0 



1.0 



10 



Fig. 31. 



20 30 minutes 60 



-Logarithms of survivors of anthrax spores plotted against the time . 

 of exposure to different temperatures. 



The computation of the death rate will prove very useful when 

 we try to understand the mechanism of the processes bringing about 

 death. It is practically impossible to define K in words that would 

 mean anything more than a description of the mathematical formula. 

 Even the relation between this death rate and P, the percentage of 

 cells surviving per unit time, is not very simple. We find 



P = 



100 



]^Q0.434X 



If we wish to compute the number of survivors b for 

 any time, we have the equation 



log 6 = log a - OASAKt 



