84 IMMUNE SERA 



the bone-marrow, spleen, and lymph bodies. Was- 

 sermann's experiments on local immunity indicate 

 that the site of infection determines largely the site 

 of the development of the immune bodies. 



Antihaemolysins : their Nature Anti-comple- 

 ment or Anti-immune Body ? A further step in the 

 study of hsemolysins is one discovered independ- 

 ently by Ehrlich and Morgenroth on the one hand, 

 and Bordet on the other. These authors succeeded 

 in producing an antih&molysin. The procedure is 

 closely related to the results gained by immuniza- 

 tion against bacterial poisons. A specific haemoly- 

 sin, one, for example, specific for rabbit blood, 

 derived by treating a guinea pig with rabbit red 

 cells, is highly toxic to rabbits. Injected into the 

 animals intravenously in doses of 5 c.c. it kills the 

 animals acutely, causing intra vitam a solution of 

 the red cells. Such a hsemolytic serum, then, acts 

 the same as a bacterial poison, and it is possible to 

 immunize against this just as well as against a bac- 

 terial poison. For example, to keep to our illustra- 

 tion, rabbits are injected first with very small doses 

 of this specific hagmolytic serum. The dose is 

 gradually increased until it is found that the animal 

 tolerates amounts that would be absolutely fatal to 

 animals not so treated. If some of the serum of 

 this animal is now abstracted and added to the 

 specific haemolytic serum, it is found that the power 

 of the latter will be inhibited. This shows that an 



