92 EXPERIMENTAL RESEARCHES 



The principle of this combinatory method of 

 therapeutics is, to attack the enemy simul- 

 taneously from two or three sides, and thus to 

 produce a completely successful result by the 

 combination of several different substances, 

 each of which alone does not show a sufficient 

 effect. Thus it has been found by Laveran 

 and by Franke that certain infections which are 

 influenced neither by trypan-red nor by atoxyl 

 alone, can be cured if these two substances are 

 used in conjunction. I, too, have in course of 

 time repeatedly met with similar cases, and am 

 convinced that substances which by themselves 

 are not very efficient, may yet produce good re- 

 sults if they are used as adjuncts to those more 

 powerful, though not completely curative, sub- 

 stances. Supposing, e.g., a highly trypanocidal 

 remedy to kill ninety-eight among one hundred 

 parasites, its administration would be followed 

 by an instantaneous improvement, but not a 

 definite cure, since the two surviving trypano- 

 somes must in course of time produce a relapse. 

 But if one combined this powerful remedy with 

 another which, even though much weaker, yet 

 sufficed to kill just those two surviving but 

 attenuated parasites, then such a combination 

 would serve to bring about the otherwise un- 



