CHEMOTHERAPY 119 



be easy to increase the actual dose of arsenobenzene. On 

 account of individual intolerance which is always possible 

 and difficult to foretell, it is not safe to inject at once a strong 

 dose of arsenobenzene, but by proceeding with a series of 

 small injections the risk of habituating a parasite as well as 

 the organism to the drug would be diminished. There is 

 therefore every inducement to attempt to find whether by 

 the injection of vaccinating doses of other antigens, the 

 tolerance of the organism for arsenobenzene can be increased 

 so that a more surely curative dose of this drug can be injected 

 safely. As to the curative or parasiticidal action of chemical 

 compounds, we can say with certainty that since they kill 

 infecting bacteria directly, all these products prevent the 

 anaphylactic state caused by bacteria much more than they 

 themselves cause them. 



The disappearance from the lesions and from the blood of 

 treponema, spirilla or trypanosomes following an injection 

 of arsenobenzene by no means proves that the product has 

 directly poisoned them. Quite frequently the same result is 

 obtained by bacteriotherapy. Cases of typhoid fever have 

 been cured by bacteriotherapy in twenty-four hours (Widal) 

 or forty-eight hours (Fournier) and here it is impossible to 

 conceive of a direct destruction of living bacteria by the 

 injection of dead bacteria. 



But at the same time we know : 



1 . That to cure a case of recurrent fever or to make trepo- 

 nema disappear from chancres in twenty-four hours requires 

 the following drug doses : 



Novoarsenobenzene 0.45gm. 



Arsenobenzene 0.25-0.30 " 



Luargol . 0.10-0.15 " 



"Product No. 219" 0.03-0.05 ' 



(This last is a product of luargol in which the silver bromide 

 is partially replaced by copper bromide). 



Intramine (of MacDonagh) 1 . 00 gm. 



2. That in the different experimental trypanosomiases 

 luargol and "product No. 219" are much more active than 



