SERUM DIAGNOSIS OF SYPHILIS. 



a. Preliminary Test Titration of the Antigen. 



i6 3 



The test proves that 0.4 c.c. of extract is not able to bind o.i c.c. of 

 complement. That 0.8 c.c. of lues extract causes only an incomplete hemo- 

 lysis, while 0.6 c.c. produces no hemolysis whatever, is explained not by its 

 lessened tendency of binding complement, but by the greater amount of 

 hemotoxin which 0.8 c.c. possesses. 



b. Examination and titration 0/4 luetic sera by Citron's method (see plate II.) 



The technical details of the test are as follows: 



Three est tubes are assigned for each test and placed into a test tube rack. The 

 name of the patient is written upon the first of these tubes. Another rack contains one 

 tube for each patient and labelled accordingly. In addition there is an " antigen tube," 

 which is placed into the first rack at the end of all the other tubes; also a "normal extract," 

 a "system," "complement," and "blood control tube," which are placed into the second 

 rack. The amount of syphilitic antigen required for the entire work is calculated as 

 follows. For each test 0.3 of antigen is required; for five cases (including controls) 1.5 



