68 IMMUNITY 



This test is positive from the initial lesions all during life unless 

 the patient has been successfully treated. Indeed the para- 

 syphilitic states also give it. The principles of the test are also 

 used for determining the presence of tuberculous, leprous, ty- 

 phoid and other anti-bodies. 



The materials necessary in the Wassermann test are as follows: 



i . Syphilitic antigen, extract from the syphilitic liver of a foetus, 

 in alcohol, ether or water; lipoids like lecithin or extracts from 

 guinea pig's heart will act as antigen. 



2 a. Serum from a known case of syphilis and containing there- 

 fore syphilitic anti-body. 



2b. Known non-syphilitic serum without anti-body. 



3. The suspected serum. 



4. Fresh serum from a guinea pig, rich in complement. 



5. Serum from a rabbit that has been immunized against 

 washed red cells from a sheep; called amboceptor. 



6. Fresh sheep's red blood cells, washed in saline and made into 

 5 percent supension. 



The solutions are all standardized so that only sufficient of each 

 is added to complete the absorption or produce the hemolysis. 

 The serum known to be syphilitic and the suspected serum are 

 heated to 56C. for thirty minutes to destroy the native and in- 

 herent complement. The rabbit anti-sheep cell serum is also 

 heated to this degree. 



The hemolytic series, i.e., sheep's cells, rabbit's anti-sheep's 

 cells serum and complement are standardized to find out what 

 quantities will exactly complete hemolysis. These quantities 

 are the units. It is necessary to control tests to find out what 

 quantity of the antigen and known syphilitic anti-body will unite 

 to bind the determined quantity of complement. The tests are 

 performed in small tubes so as to have a long column of fluid easier 1 

 to observe. Tubes are set as follows: 



