BACTERIOLYSINS AND H&MOLYSINS 95 



5 c.c. of a 5% defibrinated rabbit-blood mixture, 

 and if we find that after the immunizing process 

 0.05 c.c. of the guinea-pig serum suffice to dissolve 

 the same amount of rabbit blood, we conclude 

 that through this process the inter-body, i.e. the 

 immune body, has been increased forty times. We 

 know that the complement has not been increased, 

 but this is now able to act by means of forty times 

 increased combining facilities. This increase, how- 

 ever, is exclusively for rabbit-blood cells. In a 

 bactericidal immune serum this specific increase is 

 sometimes as much as 100,000 times that of normal 

 serum. 



The practical idea to be gained from this for 

 the therapy of infectious diseases is this: that 

 with the injection of an immune serum we supply 

 only one of the necessary constituents to kill 

 and dissolve the bacteria, and that is the immune 

 body. 



We do not, however, supply the second, i.e. the 

 complement, for this we have seen is not increased 

 by the immunizing process. As matters stand, 

 then, the use of a specific immune serum for 

 therapeutic purposes assumes that the complement 

 which is essential for the action of the immune 

 body will be found in the organism to be treated. 

 Since in certain infectious diseases the required 

 complement is present in too small amounts in 

 the organism, Wassermann suggested that the 



