RESEARCH IN MEDICINE 127 



transmitted to the rabbit and relapsing fever to the mouse, the power 

 of these preparations, as soon as manufactured, could be tested in the 

 laboratory. The object, of course, was to find a substance which would 

 kill the spirochetes without injury to the host. The result was the 

 justly celebrated Ehrlich-Hata 606, chemically known as dioxydiamido- 

 arsenobenzol, sometimes shortened to arsenobenzol, and, more recently, 

 receiving the commercial name, Salvarsan. This substance in a single 

 dose, 58 times smaller than the dosis tolerata (the largest dose which 

 could be given with safety), cured definitely chicken spirillosis; a single 

 small dose destroyed the spirolla of relapsing fever in infected mice, 

 and a single injection of one seventh the dosis tolerata, caused the 

 spirochete of syphilis to disappear completely from the experimental 

 lesions of the rabbit within twenty-four hours. This last experience 

 naturally aroused the hope of curing syphilis in man by a single injec- 

 tion given in the early stages. Such treatment, if successful, would 

 supersede, or at least supplement, the empirical treatment by mercury 

 which required a course of several years' treatment before a cure could 

 be assured. The toxicity of the substance was, therefore, tested on dogs 

 and then, to make sure it had no ill effects, on healthy men (assistants 

 of Professor Alt), who volunteered for the purpose and finally the 

 therapeutic effect was tried on relapsing fever in man. Iversen, of 

 Eussia, to whom this work was entrusted, found that one injection com- 

 pletely cured relapsing fever in 90 per cent, of his patients. Finally 

 the substance was used in the treatment of syphilis in man. The com- 

 pleteness and rapidity of the curative action have been astounding. 

 The effect on the lesions of the primary and secondary stages is to cause 

 them to heal or disappear promptly; the spirochetes can not be found 

 after a few days and the effect is apparently one of complete steriliza- 

 tion. Thousands of reports in the medical press confirm the general 

 beneficial effect of this remedy and testify to the absence of ill-effects 

 when properly administered. Even though further experience may 

 modify the present optimism, nothing can detract from the magnificent 

 service by which Ehrlich and his pupils have benefited humanity and 

 added to the glory of medical science by establishing the principle of 

 specific chemotherapy. With a record of about a dozen drugs 2 which 

 can be used to cure or modify diseases caused by nearly a dozen different 

 protozoa, 3 chemotherapy offers promise of results which, with serum- 

 therapy and vaccination in bacterial diseases, will sharply limit the 

 ravages of the transmissible diseases of man and animals. 



2 (I.) The arsenic group: arsenious acid, atoxyl, acetylatoxyl, arsenophenyl- 

 glycin and dioxydiamidoarsenobenzol. (II.) Azo-dyestuffs: trypan-red, trypan- 

 blue and trypan-violet. (Ill-) Basic triphenylmethan dyestuffs: parafuchsin, 

 methyl-violet and pyronin. 



3 Nagana, surra, sleeping sickness, mal de Caderas, Texas fever, chicken 

 spirillosis, relapsing fever and syphilis. 



