ig2 IMMUNE SERA 



dioxydiamidoarsenobenzol fulfilled the require- 

 ments. As each of the substances was tested it 

 received a laboratory number for identification; 

 dioxydiamidoarsenobenzol bore the serial number 

 606, whence the designation by which this substance 

 is still commonly known. Its trade name is " Sal- 

 varsan." 



It is not our purpose, in these pages, to enter into 

 the chemistry of " 606," or to discuss the treatment 

 of syphilis by this drug. Suffice it to say that 

 Ehrlich lays considerable stress on the fact that 

 in 606 the arsenic is in the trivalent unsaturated 

 form. Pentavalent arsenic compounds, he believes, 

 are less efficient in their trypanocidal action. As 

 supplied in the market, Salvarsan is a bright yellow 

 powder containing theoretically 34.15 per cent 

 arsenic. It is the hydrochloride of dioxydiami- 

 doarsenobenzol, and is administered by suspending 

 or dissolving it in water with the addition of NaOH 

 to neutralize, thus forming dioxydiamidoarseno- 

 benzol plus NaCl and H 2 O. Subcutaneous, intra- 

 muscular, and intravenous injections have been 

 employed, as also solutions and suspensions of the 

 drug. The results in the treatment of syphilis 

 have been encouraging, but the time has not yet 

 come to express a definite opinion concerning the 

 ultimate value of this drug. 



The principles here outlined, however, deserve 

 to be carefully studied and tested experimentally, 



