The Hemolytic Amboceptor 



289 



to precise calculation it is imperative that, in all the tests, the same 

 quantity of added serum be employed. Experience has shown this 

 quantity to be 0.2 cc., and this we regard as the unit of serum to be 

 tested. 



To titrate the antigen we require (i) a normal human serum and 

 (2) a known syphilitic serum, obtained from blood drawn from the 

 arm veins of cases known to be well and cases known to be syphilitic 

 respectively. These serums should be kept on hand in the labora- 

 tory in considerable quantity, as they are constantly needed for 

 making the controls that must accompany each test, as well as for 

 making the preliminary titration of the antigen. 



Tubes 

 i. i unit of 



TABLE I. Series with the Normal Serum 



i unit of + antigen o.oi 

 complement normal serum 

 2. " + " + ''0.03 



Complete 

 hemolysis. 



