MECHANISM OF DEATH 



309 



Apparently, the coefficient is not constant, but the 

 data are too few to warrant conclusions. So much seems 

 certain, however, that the temperature coefficient of 

 death through drying is similar to that of common 

 chemical reactions, i.e., it lies between 2 and 3. Rogers 

 (1914) found the temperature coefficient of the death 

 rate of dry streptococci to be 3.6 between and 30°C. 



It seemed interesting to determine the temperature 

 coefficient at temperatures which exceeded the range of 

 normal growth temperatures. Upon the author's sug- 

 gestion. Dr. H. H. Boysen made three series of experi- 

 ments with dry yeast cells keeping them between 30 

 and lOO'^C. The distribution of cells in the strata used 

 (infusorial earth or sand) was not sufficiently uniform 

 to use the data directly. They were accurate enough, 

 however, to compute the times required to kill 99% 



Table 91. — Time Required to Kill 99% of the Cells op Dry 



Yeast 



(Temperature coefficients) 



