200 



COLLOIDS IN BIOLOGY AND MEDICINE 



from a solution that is concentrated. EISENBERG and VOLK* dem- 

 onstrated this for typhoid bacilli and cholera vibrios and Sv. 

 ARRHENIUS* and his co-workers for hemolysins (see also G. DREYER, 

 J. SHOLTO and C. DOUGLAS*). 



This is illustrated by a table (after EISENBERG and VOLK) showing 

 the combination of agglutinin with a uniform quantity of typhoid 

 bacilli and increasingly concentrated agglutinin solutions. 



The course is entirely that of an adsorption curve. 



Cases also occur, according to the investigations of G. DREYER, J. 

 SHOLTO and C. DOUGLAS* in which, after exceeding a certain maxi- 

 mum, less and less agglutinin is taken up by the bacteria, in spite of 

 greater concentration of the agglutinin, typical " abnormal adsorp- 

 tion." 



It may be mentioned, moreover, concentrated salt solutions inter- 

 fere with the fixation of agglutinin (until now this had been 

 demonstrated only for blood corpuscles). (K. LANDSTEINER and 

 ST. WELECK.) Analogous to this is an observation of W. BILTZ,* S 

 according to which the addition of salt interferes with the adsorp- 

 tion of proteins by inorganic colloids. 1 



As has been stated elsewhere, hemolysis with immune sera occurs 

 through the interaction of two components; amboceptor is bound by 

 the blood corpuscles and it causes the fixation of the complement 

 which accomplishes the hemolysis. This is obviously very similar 

 to what occurs with mordant and dye; the dye is fixed to the fiber 

 by means of the mordant. K. LANDSTEINER and N. JAGIC* have to a 

 certain extent devised a model for the process; as amboceptor they 

 use silicic acid hydrosol, as complement active serum or lecithin. 



Silicic acid precipitates with blood corpuscles as well as with leci- 

 thin; it thus links together blood corpuscles and lecithin, concentrating 



1 In my opinion it is chiefly globulin which has been strongly adsorbed in 

 these experiments, since the final portion of globulin is separated very slowly from 

 dialyzed serum. 



