642 
The experiments taught that the value of £ is not well nigh 
constant, but diminishes progressively, so that the logarithmic curve 
is convex on the side of the abscissae. (Fig. 11). 
Since it was evident from Fig. 1 that anthrax spores were vulne- 
rable at a temperature of 80°, the samples were heated up before 
plating to 70° only. 
Ill. Conclusions. 
1. As regards disinfection of micro-organisms (vegetative forms 
as well as spores) some species are killed off in an orderly progress 
analogous to the process of a unimolecular reaction. 
In the case of other species the velocity of disinfection is not 
constant, but either decreases or increases in the course of the process. 
However with them a certain regularity is also to be observed, viz. 
apart from the period of induction, the value of / alters in the same 
experiment continuously in the same sense. 
Most often every species has a definite type expressing the orderly 
progress of its disinfection. Some there are however affording different 
types in different cultures of the same species; for this variability 
no satisfactory interpretation can be given. 
It is still a matter of doubt, whether the progress of disinfection is 
chiefly a physico-chemic phenomenon, or whether differing individual 
resistance of micro-organisms of the same culture play a principal 
part in the process. 
2. A striking analogy is to be observed in the orderly progress 
Disinfection Germination 
Small spores 
Anthrax sp res IN 
Large spores 
Fig. 12. Types of logarithmic curves. 
