BINDING OF II.EMOLYTIC AMBOCEPTORS. 599 



determined the quantity of blood-cells which would just be 

 completely dissolved by a hsemolytic serum when the cells were 

 added at once. He then divided the blood-cells into two equal 

 parts, added one part and then the other after the first had been 

 hsemolyzed. The second portion remained undissolved. Bordet 

 incorrectly interpreted this as indicating a physical adsorption 

 of the amboceptor, but, as already indicated, 1 the phenomenon is 

 due to the fact that the blood-cells bind multiples of the amboceptor 

 unit. 



Attempts to liberate bacterial agglutinins from their combina- 

 tion with the cells were, made some time ago by Hahn and Tromms- 

 dorff. 2 These investigators treated agglutinated bacteria with 

 weakly alkaline and weakly acid solutions and actually succeeded 

 in liberating a portion of the bound agglutinin. The agglutinin 

 so liberated was still active. More recently Landsteiner 3 succeeded 

 in liberating the agglutinin from agglutinated blood corpuscles by 

 digestion with physiological salt solution at 50. This author, 

 moreover, found that even at lower temperatures a certain amount 

 of agglutinin passed into the salt solution used for washing the agglu- 

 tinated cells, and he therefore concludes, probably correctly, that 

 the combination of cell and agglutinating substance decomposes 

 even at ordinary temperatures, though to a less degree than at 

 higher temperatures. 



It is necessary constantly to call attention to the significance 

 of the chemical union of the amboceptors for a correct understanding 

 of the fundamental principles of the immunity reactions. We 

 are here dealing with a chemical binding which is unaccompanied 

 by any toxic action whatever, but which at any time, through the 

 addition of complement, can become manifest by such action. Just 

 this makes it possible to demonstrate the essential distinction 

 between the chemical binding and toxic action, a distinction which 

 finds its expression in the separation of the toxin molecule into a 

 toxophore and a haptophore group. Gruber and Durham 4 were 

 the first to demonstrate the fact that cholera vibrios could remove 

 cholera-immune bodies. Since, however, they identified these 



1 Ehrlich and Morgenroth, loc. cit. 



2 Hahn and Trommsdorff, Miinchener med. Wochenschrift, No. 13, 1900. 



3 Landsteiner, Wiener klin. Rundschau, No. 40, 1902, and Miinch. med, 

 Wochenschrift, No. 46, 1902. 



4 Gruber, Wiener klin. Wochenschrift, No. 12, 1896. 



