BACTERIOLYSINS AND HMMOLYS1NS 51 



mal species treated with blood cells of a different 

 species. We can formulate this as follows: The 

 serum of animals, species A, after these have been 

 injected either subcutaneously, intraperitoneally, 

 or intravenously with erythrocytes of species B, 

 acquires an increased solvent action for erythro- 

 cytes of species B, and only for this species. 1 It 

 is therefore a specific action. We call this hcc- 

 molysis, and the substances which effect the solution 

 of the red cells, hcemolysins or hcemotoxins. 



At about the same time, and independently of 

 Bordet, similar experiments with similar results 

 were published by Landsteiner 2 and v. Dungern. 3 

 As a result of this work, the acquired toxicity of 

 horse serum, found by Belfanti and Carbone when 

 they treated horses with red cells of rabbits, was 

 explained. The serum of the horses so treated had 

 become hcemolytic for rabbit blood, and therefore 

 caused a solution or destruction of the red cells 

 in the living body just as it did in a test-tube. 



Nature of Hocmolytic Sera. In a subsequent 

 study Bordet 4 was able to show that the sol- 

 vent power of the specific haemolysins depended 

 on the combined action of two constituents of the 

 specific serum. When the fresh hsemolytic serum 

 was warmed for half an hour to 55C., it lost its 



1 We shall point out a few exceptions later on. 



2 Landsteiner, Centralblatt Bacteriol. Vol. xxv, 1899. 



3 Von Dungern, Munch, med. Wochenschrift, 1898, 

 * Bordet, Annal. Inst. Pasteur, Vol. xii, 1898. 



