THE PHENOMENA OF ADSORPTION. 457 



in this mixture are not sensitizing for the corpuscles used, they 

 must be treated with an appropriate specific immune serum. Such 

 is the case in the experiment with bovine corpuscles. Many 

 corpuscles, however, react sufficiently to the sensitizer in normal 

 serum, particularly in bovine serum. Thus in Ehrlich and Sachs' 

 experiment the guinea-pig corpuscles may be replaced by other 

 red blood cells. For example, rabbit corpuscles act just the same 

 as guinea-pig corpuscles and show conglutination, although some- 

 what less rapidly, and intense hemolysis. Human corpuscles 

 react distinctly. In all these instances fresh bovine serum alone 

 produces similar results. 



Goat corpuscles act rather curiously on the addition of fresh 

 bovine serum. They are energetically conglutinated, but are not 

 hemolyzed. We should conclude from this fact that the bovine 

 serum sensitizes goat corpuscles sufficiently to produce alexin 

 absorption and bring about the action of the conglutinin, but that 

 the alexin acts poorly in producing hemolysis, owing perhaps to the 

 fact that the ox and the goat are closely related species.* In the 

 phenomena under consideration, hemolysis is due neither to the 

 alexin nor to the conglutinin alone, but to the combined effect of 

 the two factors; the complex alexin-conglutinin does the hemoly- 

 zing, and we shall see presently that the conditions under which 

 this complex is formed are of importance in respect to the strength 

 of the hemolytic or the agglutinating property which it produces. 



Why does the sensitized and alexinized corpuscle unite with 

 the conglutinin? The absorption of alexin (complement) by a 

 sensitized corpuscle is due, as we know, to a phenomenon of ad- 

 sorption. But to what is this adsorption due? Neither the 

 corpuscle itself nor the sensitizer alone shows any such attrac- 

 tion for the alexin. The corpuscle and the sensitizer when they 

 unite, however, form a complex which is endowed with the new 

 property of alexin absorption, owing doubtless to the fact that 

 the sensitizer produces a change of physical condition in the cor- 

 puscle and sort of coagulation similar to that brought about by 

 adding specific precipitating serum to an albuminous solution. 

 This formation of a precipitate would affect the contact proper- 



* Bovine alexin fails to hemolyze, or hemo-lyzes only faintly, goat corpuscles 

 even when they are sensitized by a specific immune serum. 



