THE WASSERMANN REACTION 



623 



dilutions of antigen and complement, and for the sheep's cor- 

 puscles. All pipettes are of the long form graduated to the point. 

 Test-tubes of thick glass in ordinary test-tube racks are used 

 for the reagents 4 in. x f in. for complement dilutions and 

 for complement- saline and complement -antigen mixtures, and 



FIG. 56. Apparatus arranged for Wassermann test (small-volume 

 method : 



a. Electrically-heated water-bath. 



b. Metal rack for small tubes. 



c. Wooden block drilled with holes for small tubes. 



d. Another form of metal rack for small tubes ; it may be immersed 

 in a water-bath. 



e. Test-tube rack with test-tubes and throttled pipettes. 



/. Small tube containing complement set in a block of plasticine. 

 g. Cylinder with pipettes. 



5 in. X | in. for corpuscles, antigen dilution and corpuscle- 

 amboceptor mixture. 



For standardisations and for the test, small " quill '' tubes, 

 2 in. long by in. (6-25 mm.), external diameter, are used. They 

 should be made of glass tubing, not too fragile, and for convenience 

 of cleaning should have rounded (not pointed) bottoms. Racks 

 (Fig. 56, b and d), or blocks of wood with holes of appropriat 



