THE PHENOMENA OF ADSORPTION. 449 



the conglutinin, in the bovine serum, which has never been de- 

 scribed in other sera. But as we know, bovine serum is in itself 

 rather unusual and why should not the effect that it produces be 

 likewise so? Ehrlich and Sachs' theory, moreover, is also rather 

 exceptional inasmuch as it presupposes that a sensitizer does not 

 unite with the corpuscles when the alexin is absent. 



(b) Sachs and Bauer seem to consider it axiomatic that the 

 properties of agglutination and hemolysis cannot be attributed to a 

 single substance. Gengou, as we know, has noted that a suspension 

 of barium sulphate will agglutinate and hemolyze red blood cells. 



(c) In their criticism of our work our contradictors concern them- 

 selves only with the hemolysis. They make no attempt to explain 

 the marked clumping of the corpuscles and do not mention whether 

 they consider our interpretation, at least in so far as this congluti- 

 nation is concerned, as admissible. 



(d) Sachs and Bauer insist strongly on the fact that heated bovine 

 serum is capable of sensitizing guinea-pig corpuscles. We know 

 this fact and have never denied it. We have simply said that in 

 the Ehrlich and Sachs' mixture the bovine sensitizer is unnecessary 

 on account of the presence of a similar stronger substance in horse 

 serum. 



(e) The activity of heated bovine serum is due to the fact, accord- 

 ing to Bordet and Gay, that sensitized and alexinized corpuscles 

 absorb the conglutinin. For example, if bovine corpuscles are sen- 

 sitized with a specific immune serum from the rabbit, subsequently 

 treated with horse alexin, and, after being carefully washed, heated 

 bovine serum is added, this latter serum loses, if not all, at least part 

 of its conglutinin and becomes much less able to form a congluti- 

 nating and hemolytic mixture with horse alexin either for bovine 

 corpuscles or for guinea-pig corpuscles. Bordet and Gay have made 

 this assertion. The experiment is, however, denied by Sachs and 

 Bauer. 



We are dealing here, not with an interpretation, but with a fact, 

 and we insist on its accuracy. In the same way Sachs and Bauer 

 say that guinea-pig corpuscles that have been treated with fresh 

 horse serum, then washed and mixed with heated bovine serum, do 

 not deprive this latter of its activity. We have repeated this exper- 

 iment with different results; to be sure, we have taken pains to use a 



