IMMUNITY. 395 



heighten the general immunity, as indeed Pet- 

 tenkofer and G. Jager have demonstrated. A 

 properly nourished and exercised body is able 

 to cope with many species of bacteria simply 

 by means of its normal body cells and fluids, 

 without its being necessary for us to assume 

 the existence of anything heterogeneous and 

 " specific ". 



It is demonstrable, therefore, in ways that 

 differ quantitatively according to the method 

 used, that by means of very various impulses 

 the natural protective and defensive forces of 

 the human organism, of its organs, tissues, 

 cells and fluids can be made active or by stimu- 

 lation raised above the normal. The liberat- 

 ing stimulus then becomes, as it were, a stimu- 

 lus to increase resistance. It may even be 

 that stimuli of entirely different characters 

 evoke a defensive reaction as great as was 

 formerly attributed only to specific stimuli, 

 whereas the latter stimuli sometimes bring 

 about only a tolerably moderate defensive re- 

 action. In general, however, the defensive re- 

 action which is provoked by isopathic or 

 specific stimuli is the stronger and more per- 

 sistent and hence often appears to be peculiar 

 in kind. But we can really understand every- 

 thing that the mysterious doctrine of specifi- 

 city has tried zealously to render obscure by re- 



