EQUILIBRIA IN ABSORPTION PROCESSES 147 



in such observations, the conclusion does not seem to pos- 

 sess a very high degree of accuracy. And even if this 

 were the case, it is very probable that the quantities of 

 bacteria separated out in the first fractions were rather 

 small, and under such circumstances it was evidently to 

 have been expected that the total quantity of agglutinin 

 in the two experiments would be nearly the same. 



Now in regard to the figures of Eisenberg and Volk, it 

 is evident that a relation exists between the absorbed quan- 

 tity of agglutinin C and the free quantity B. This rela- 

 tion may be expressed in a very simple mathematical 

 formula, namely: 



With the aid of this equation the calculated figures ^ calc . 

 are found. They agree very well with the observations, 

 within the errors of observation, as Dr. Eisenberg also has 

 stated. The only observation in the second series which 

 gives an unsatisfactory agreement between the observed 

 and calculated values is where ^ Ob8 . = 80 and B c&lCf = 27. 

 Eisenberg and Volk themselves state in their original 

 memoir that this observation must be influenced by some 

 occasional error. 



The physical interpretation of the above formula is very 

 simple. It states that the agglutinin molecules are divided 

 between two solvents, the bacterial cells and the sur- 

 rounding medium, and that of two molecules of the free 

 agglutinin are formed three molecules of the absorbed 

 agglutinin. 



In the experiments of Ransom cholesterin is a sol- 

 vent for saponin, and the existence of cholesterin in the 

 red blood-corpuscles causes the entrance of the haemo- 



