98 APPLIED IMMUNOLOGY 



more than one-third of the anticomplementary dose 

 used. The comparative results of tests with syphilitic 

 liver-extract and cholesterinized guinea-pig heart-ex- 

 tract may be divided into four groups as follows : 



1. In twenty-two cases the results were positive 

 with both antigens, with little or no diiFerence in de- 

 gree of reaction. 



2. In eight cases the syphilitic liver-extract gave a 

 weakly positive reaction, while the cholesterinized ex- 

 tract gave a stronger reaction. 



3. In thirty-six cases both antigens gave a negative 

 result. 



4. In thirty-four cases the syphilitic liver-extract 

 gave a negative reaction, while the cholesterinized 

 heart-extract gave a weakly positive or medium posi- 

 tive result. This is naturally the most important 

 group from the clinical point of view. Nine of these 

 thirty-four cases were treated cases of syphilis ex- 

 hibiting no symptoms, showing that it is more difficult 

 to render the serum negative to the cholesterinized 

 heart-extract by anti-syphilitic treatment. The re- 

 maining twenty-five of this group were cases sub- 

 mitted for diagnosis or which had no signs or history 

 of syphilis. When one antigen reacted more strongly 

 than the other, it was always the cholesterinized heart- 

 extract. In no case did the syphilitic liver-extract give 

 a stronger reaction than the cholesterinized extract. 



