APPENDIX 321 



mercially known as " neosalvarsan." It may be represented 

 by the following structural formula: 



As As As 



NH, I 1 = 11 NH, + HO.CHASONa = NH, | | = 



As 



I NaCHjO.SONa-f HjO 

 OH 



( 



Neosalvarsan appears as an orange-yellow powder of pecu- 

 liar odor, dissolving very easily in cold water with completely 

 neutral reaction. 



Neosalvarsan is even more unstable than salvarsan, and 

 although slightly less trouble to prepare for administration, 

 requires even greater precaution as to freshness and tem- 

 perature of solution, owing to its greater proclivity to oxidi- 

 zation and the formation of products of a high degree of 

 toxicity. Unfortunately, its ease of solution in water, at 

 once in a neutral state ready for administration, and better 

 toleration by patients, does not outweigh the greater effec- 

 tiveness and spirochaeticidal power of salvarsan, the injec- 

 tion of which with proper care and technic is attended with a 

 minimum degree of reaction. 



Indications. — Salvarsan or neosalvarsan is indicated in 

 all stages of syphilis, and should be the first thought in treat- 

 ment, provided no contra-indications exist. Indeed, in the 

 early primary stage cure may often be obtained by the ad- 

 ministration of salvarsan alone, particularly before the ap- 

 pearance of a positive Wassermann reaction. It seems es- 

 pecially effective in those cases where mercury and iodine 

 have failed. In cerebrospinal syphilis the effects are vari- 

 able. For instance in gummatous meningitis, whether diffuse 

 21 



