MECHANISM OF DEATH 



321 



did various authors. The results are compiled in Table 

 97. We are dealing here with unusually high tem- 

 perature coefficients, corresponding to those for the 

 destruction of enzymes (p. 129). 



The only exception to these high temperature coefficients are the 

 results obtained by Sattler (1928) on death rates of bacteria in milk. 

 He measured the following temperature coefficients: 



Table 98. — Temperature Coefficients of Death by Heat in 



Milk 

 (Temperature interval) 



62-80°C. 



Average 



80-99°C. I Average 



Micr. sulfureus 



Micr. pyogenes aureus 



Bad. aerogenes 



Ps. fluorescens 



Pink Torula 



4.9 

 2.1 

 2.1 

 1.4 

 1.2 



5.1 

 2.3 

 2.3 

 1.7 

 1.2 



5.4 



2.6 

 2.7 

 2.1 



5.6 

 3.4 

 3.0 

 2.4 



5.3 

 2.6 

 2.5 

 2.0 

 1.2 



2.1 

 1.2 



1.3 



1.71.7 



1.4 



2.4 

 1.6 



2.3 

 1.4 

 1.7 



The reason for these low coefficients must be sought in the great 

 range of temperatures. Skrabal (1916) has pointed out that the 

 temperature coefficient is not constant, but must decrease with 

 increasing rates of reaction. The change is slight with normal 

 coefficients, but is great with abnormal coefficients such as those 

 observed with death-rates. Skrabal computed from the results of 

 Arthur Meyer (1906) and of Ballner (1902) the following temperature 

 coefficients : 



Qio at 0°C. Qio at 100°C. 



^^OTQS oi B. suhtilis 19.6 4.9 (A.Meyer) 



Spores of B. robur 30.8 6.3 (A. Meyer) 



Spores of B. anthracis 69.7 9.7 (Ballner) 



A striking experimental example is given by Henderson Smith (1923) 

 for spores of Botrytis cinerea: 



at 31.0 to 37.0°C., Qio = 690 

 37.0 to 44.3 132 



44.3 to 47.0 92.8 



47.0 to 50.3 29.5 



