The Serum to be Tested 



281 



the present we must be content to follow the beaten path, and for 

 this purpose will use the congenitally syphilitic liver extract as the 

 antigen, preparing it as described above. 



(2) The Serum to be Tested. Wassermann, Neisser, and Bruck 



Fig. 103. The Kei- 

 del tube for collecting 

 blood. (Manufac- 

 tured by the Steele 

 Glass Co., of Phila- 

 delphia.) 



Fig. 104. Parts of the Keidel tube. E is the 

 vacuum bulb which is attached to the needle by a 

 piece of rubber tubing (Z>); the glass tube (B) 

 covers the needle and the whole is sterilized. 

 (Kolmer.) 



at first employed the cerebrospinal fluid, but now the blood-serum 

 of the suspected patient is almost universally used. As is usual 

 with antibodies, the substances engaging in the complement-fixation 

 test are widely distributed throughout the body, and reach the 



