That there occurs in certain human serums a substance which hemolyzes sheep corpuscles in the presence of complement has been known for a considerable time. It has been our purpose to find out how much the presence of this substance in serums which reacted positively to the Wassermann test could affect the final result of the reaction.
In 1908 Bauer1 pointed out that use might be made of this substance — to which we shall refer as native antisheep amboceptor — in the complement fixation test for syphilis, and he suggested substituting this native amboceptor for the rabbit sheep amboceptor used in the Wassermann reaction. The Wassermann technic would be simplified in this way, as one of the reagents would be eliminated without endangering its accuracy. This procedure is known as the Bauer modification of the Wassermann reaction. Shortly after this, Bering2 reported a series