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enumerated. Having found that salvarsan cured 

 syphilis in animals the next step consisted in test- 

 ing the effects of the drug on man, several German 

 professors submitting themselves to being dosed 

 with the drug without harmful consequences. 

 Finally the drug was tested on syphilitic men, with 

 brilliant results which have since led to its adoption 

 in the treatment of this dread disease throughout 

 the world. 



We come finally to the remarkable curative 

 effects of salvarsan which Ehrlich discovered in 

 relapsing fever. This disease occurs among people 

 living in filth and neglect, and it has been demon- 

 strated that it is transmitted by the bites of lice 

 which have previously sucked the blood of the sick. 

 In past times as in the present relapsing fever has 

 been a scourge of armies in the field, for soldiers 

 on campaign commonly become verminous. The 

 cause of the disease is a minute spirochaete, differ- 

 ing somewhat from that of syphilis and multiply- 

 ing in the blood. The disease, as its name implies, 

 is characterized by periodic attacks of fever or re- 

 lapses which correspond with the appearance in 

 the blood of enormous swarms of actively moving 

 spirochaetes which disappear with the subsidence 

 of each attack. Relapsing fever is not usually a 

 very fatal disease, the death-rate generally averages 

 4% but it may be greater. The seriousness of the 

 disease is due to the long period of invalidism which 

 may follow. The heart may be so weakened as to 



