EQUILIBRIA IN ABSORPTION PROCESSES 151 



As will be seen from the figures, the agreement between 

 the observed and the calculated figures is just as good as 

 for the agglutinins, and wholly within the possible errors 

 of observation. The same physical explanation evidently 

 holds good for both phenomena. 



In some recent investigations bearing upon the absorp- 

 tion of coli-agglutinin in the bodies of the Bacillus colt com- 

 munis, Dreyer has found that not only the constant K, 

 but also the exponent n in the equation C= KB* may turn 

 out different in different experiments, n always falls near 

 unity, sometimes it exceeds it, e.g. in one case n was found 

 to be 1.25. A closer investigation regarding the cause of 

 this variability seems very desirable. 



This case has a certain theoretical significance. Quite 

 recently the opinion has often been ventured that the ab- 

 sorption of agglutinin by bacteria might be analogous to 

 the so-called adsorption of dissolved substances by char- 

 coal, or of colouring matter by organic tissues. Bordet was 

 the first to make this assumption, which has recently been 

 upheld by Wilh. Biltz. Biltz now states that in the theo- 

 retically hitherto little elucidated adsorption-process n is 

 always lower than i ; for absorption by charcoal it is 0.25, 

 according to Schmidt. If therefore n is sometimes found 

 to exceed i, as in Dreyer's work, we have to abandon the 

 adsorption hypothesis. Biltz, Much, and Siebert for two 

 hours shook typhoid agglutinin with the following colloidal 

 bodies : silicic acid or hydroxids of iron, zircon, and tho- 

 rium. It was found that silicic acid had a noticeable and 

 the three other substances a much greater destructive action 

 on the agglutinin. This seems to indicate that we have 

 here to deal with a real chemical influence, which is not 



