264 CHEMOTHERAPY 



serum-fast strains can exist, and we accordingly find that after a 

 patient has safely passed through the two or three corresponding 

 relapses, spontaneous recovery occurs, there being then antibodies 

 present against the only strains that are possible in that particular 

 milieu. In syphilis it is quite different. Here the number of food- 

 stuffs that the spirochete can utilize is evidently quite large. In the 

 untreated individual, relapse follows relapse, and the damage done 

 to vital parts is only too often so extensive, relatively early in the 

 course of the infection, that the patient succumbs, owing to the 

 resultant injury, long before the disease has "worn itself out." 



The discovery of this element of "fastness" or resistance on the 

 part of microorganisms is evidently of the greatest importance, as 

 it throws light upon many phenomena, the cause of which has here- 

 tofore been most obscure. The question has thus long remained 

 unanswered, why the syphilitic individual cannot be re-inoculated 

 with syphilitic virus while his disease is active. The reason now is 

 quite evident. For we know that the spirochetal strains which at 

 any time are operative in the body of the syphilitic patient are 

 "fast" strains, of varying degree, and that antibodies are present 

 in his blood which are specifically "tuned" to those of a lower 

 order, i. e., to those serum strains from which the "highest" ones 

 have become developed, so that the "street spirochete," so to speak, 

 if introduced under such conditions, must of necessity meet with 

 those antibodies which would lead to their destruction. If once it 

 were possible to cultivate all these different strains, then it would 

 also be possible to reinfect the syphilitic individual, not with the 

 street virus to be sure, but with a strain of a higher order of serum 

 fastness, than would correspond to the number of antibodies that 

 have already been formed. In the animal experiment, using try- 

 panosomes, this can indeed be done at the present time, and at the 

 Speyer Haus, in Frankfurt, Ehrlich has under cultivation all five of 

 the serum-fast strains which are possible in the organism of the mouse. 



Therapia Magna Sterilisans. As the development of "fast" strains 

 is thus one of the greatest impediments to the successful treatment 

 of the maladies in question, our efforts should be directed to the 

 discovery of medicinal substances which should be capable of effect- 

 ing the complete sterilization of the individual at one time (Ehrlich's 

 therapia magna sterilisans) . The demonstration that this is actually 

 possible, not only in the infected animal, but also in the infected 

 human being, we also owe to the indefatigable genius of Ehrlich. 



