THE CAUSE OF INFECTIOUS DISEASE. 24! 



nomena that we find in inorganic processes, but 

 they are better regulated and more intricate, in 

 the first place because of adaptation, and in the 

 second, because of the complexity of the phe- 

 nomena involved. We find various forms of 

 potential energy or internal causes which may 

 be transformed into kinetic energy, into work 

 or into effect. The effect, so far as its special 

 features are concerned, depends solely upon the 

 qualitative character of the compound, that is to 

 say, the mode of union of the atoms in the 

 molecule. This qualitative relation is more 

 striking in the realm of the organic than in 

 the inorganic, where it has been recognized 

 from the time of R. Mayer to that of Hertz 

 that qualitative relations may be overridden. 

 At bottom, however, exactly the same sub- 

 jective limits wall us in, although that is a 

 fact that need not be dwelt upon here. Every 

 quality is of course from one point of view a 

 sort of sense-illusion or sense-limit, and not 

 anything truly objective. We find forms of 

 resistance, then, which result from character- 

 istics of molecular structure and therefore pre- 

 sent not only the well-known quantitative but 

 also a qualitative side worthy of consideration. 

 Finally we need to consider the liberating 

 impulses which quantitatively and qualita- 

 tively serve to remove the resistance. We 

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