THE METHOD OF COMPLEMENT FIXATION. 



As has been repeatedly remarked, specificity is the important element in 

 every biological reaction. The reaction known after the discoverer as the 

 Wassermann Reaction, can also be performed if instead of the extract from 

 luetic organs, an alcoholic extract of certain normal organs or certain lipoid 

 substances is substituted as antigen. Seligmann too, was able to obtain 

 complement fixation by pure chemical reactions. Consequently, numerous 

 authorities expressed the opinion that the Wassermann Test was non- 

 specific and that it does not at all represent an antigen antibody interaction. 



There is no doubt, however, that this exceptional view is incorrect. It is true that the 

 real syphilitic antigen is unknown, but most probably it is neither the pure spirochaetes 



