SALVARSAN IN THE TREATMENT OF SYPHILIS 251 



possible, not only in the infected animal, but also in the infected 

 human being, we also owe to the indefatigable genius of Ehrlich. 

 To give an idea of the immense amount of labor which this 

 work has involved it will be sufficient to point out that up to the 

 year 1910 over six hundred arsenical products alone had been pre- 

 pared and tested biologically and therapeutically under Ehrlich's 

 direction. Of these the one carrying the number 606 has been of 

 special interest to clinicians, as its wonderful therapeutic effect upon 

 trypanosome infections and certain spirilloses of animals (notably 

 the spirillosis of relapsing fever and chicken spirillosis) suggested 

 the idea that the product might be similarly effective in the treat- 

 ment of human syphilis (see Plate IV). After preliminary studies 

 had then shown that a single dose of the substance is capable 

 of causing the complete destruction of all spirochetes in syphilis- 

 infected rabbits, with the complete cure of the testicular chancre 

 and without the occurrence of a relapse, it was clearly indicated that 

 corresponding experiments in the human being were justifiable (see 

 Plate V) . After the first trials in this direction had then demonstrated 

 a similarly beneficial effect, Ehrlich placed the remedy in the hands 

 of a large number of special workers in this field in order that a 

 conclusion should be reached as soon as possible regarding its thera- 

 peutic value, the indications and contraindications to its use, the 

 question of dosage, mode of administration, etc. As a consequence 

 reports on these questions could be collected within a year, covering 

 the administration of the remedy in many thousands of cases, so 

 that in a relatively short time the verdict could be reached that 

 preparation 606, or salvarsan, as it is now termed, actually constitutes 

 the most potent remedy which we have at our disposal for the 

 treatment of syphilis; and I would emphasize once more that this 

 discovery was not the result of accident, but the outcome of carefully 

 planned experimentation, carried to its logical issue. 



SALVARSAN AND ITS USES IN THE TREATMENT OF SYPHILIS 



Chemically speaking salvarsan (Ehrlich's "606") is the dichlor- 

 hvdrate of dioxvdiaminoarsenobenzol : 



As = As 

 /\ /\ 



NH 2 



NH 2 



