196 APPENDIX 



when it is derived from syphilitic material, has 

 something of a specific character. In this connec- 

 tion Wassermann refers to the researches of 

 Noguchi, Landsteiner, and others which show that 

 minute quantities of proteid mixed with lipoids 

 may cause, extensive alterations in the physico- 

 chemical behavior of the latter. He thinks that 

 under certain circumstances this proteid component 

 may play an important role in determining the 

 reliability of the reaction, a view which is borne out 

 by the investigations of Neisser and Bruck. 



While Forges and Meier were engaged in the 

 studies just mentioned, Fornet and also Michaelis 

 showed that when the serum of individuals infected 

 with syphilis was mixed with certain antigens a 

 zone of precipitation might at times be observed at 

 the point of contact of the two fluids. The antigen 

 employed by Fornet was serum from individuals in 

 the florid stage of syphilis ; Michaelis used extracts 

 of organs from a syphilitic foetus. This of course 

 agrees with what was already known from the work 

 of Bordet, Gengou, and Gay. In fact, according 

 to Gay, the deflection or absorption of complement, 

 on which the Bordet-Gengou test depends, may be 

 due to the precipitate formed in the combination. 



Forges and Meier thereupon tested the alcoholic 

 extracts, and solutions of lecithin and of glycocho- 

 late of soda to see whether this zone of precipita- 

 tion was at all constant, and whether it might not 

 be possible to substitute such a simple precipitation 

 test for the complicated Wassermann reaction. 



