MECHANISM OF DEATH 



323 



plotted against temperature should be a straight line in case the 

 coefficient is constant. This is shown to be true with the spores of 

 thermophilic bacteria by Bigelow (1922). 



In Table 99 are given the data as averaged by Bigelow for the 

 fifteen most typical spore-formers. If we compute the temperature 

 coefficients from these data, it becomes at once evident that they 

 are not very constant, but fluctuate considerably. 



Table 99. — Time Required to Kill All Spores op Thermophilic 



Bacteria 

 (Averages of 15 experiments by Bigelow) 



The kilhng times beyond 125°C. are so short that the time required 

 for the heat penetration must necessarily mean a considerable part 

 of the total observed. Hence, probably all these data are too high, 

 and the actual time required for kilUng must be much shorter. 

 The average of all temperature coefficients from 100-125°C. is 8.77. 



These data are plotted logarithmically in Fig. 36. In plotting 

 curves from data by the endpoint method, the definite points are 

 changed to lines, and the correct point lies somewhere on this Une. 

 This adds to the inaccuracy of plotting. Owing to this and to the 

 fact that logarithms make deviations appear much smaller, the 

 curves of Fig. 36 are very straight, showing hardly any fluctuations, 

 while the temperature coefficients computed from the same data 

 fluctuate widely. 



In the same figure are included some data by Weiss (1921) on the 

 death of spores of Clostridium hotuUnum and also the data of Ballner's 



