PRINCIPLES OF CHEMOTHERAPY 



791 



reinoculated with syphilis while his disease is active. That he is vul- 

 nerable to syphilis is evidenced by the activities of the spirochetes within 

 his tissues and body-fluids. But this is so because a race is at work 

 that is resistant to the antibodies first produced, whereas these anti- 

 bodies are still potent and capable of killing a fresh, non-resistant race 

 of spirochetes. 



The theory of chemoreceptors affords an explanation of this phe- 

 nomenon, just as the side-chain theory affords an explanation of the for- 

 mation of cellular antibodies and the processes of immunity. In adopt- 

 ing it we must be prepared to believe that the number of receptors and 

 the possibilities of their repair or modification are practically unlimited, 

 as evidenced by the large 

 number of substances capable 

 of exerting toxic action. Syph- 

 ilis, for example, is probably 

 a disease of great antiquity, 

 handed down from person to 

 person, from generation to gen- 

 eration, during which trans- 

 mission the receptors of the 

 spirochete must have under- 

 gone innumerable transforma- 

 tions and alterations, yet find- 

 ing suitable receptors in the 

 cells of practically all non- 

 syphilitic persons, although it 

 is now apparent that strains 

 have gradually been evolved 

 that possess receptors with 



marked affinity for certain tissues, as, for example, those for the central 

 nervous system, cardiovascular system, etc. 



Therapia Magna Sterilisans. As the development of resistant 

 strains is thus one of tihe possibilities and impediments to successful 

 specific therapy, whether with chemicals (chemotherapy) or with anti- 

 bodies (serum therapy), our efforts should be directed toward discover- 

 ing chemical substances and a method of administration that will com- 

 pletely sterilize the individual at one time (Ehrlich's therapia magna 

 sterilisans). This possibility has been amply demonstrated experi- 

 mentally by Ehrlich, and it has occasionally been accomplished in the 

 1 "Die Behandlung der Syphilis" (Konigsberg Versammlung), Leipzig, 1910, 930. 



FIG. 140. BLOOD OF A RAT INFECTED WITH 



SPIROCH^TA RECURRENTIS. 



(Drawing made from dark-field illumination 



just before administration of salvarsan.) 



