56: 



IDENTITY OF OPSONINS WITH NORMAL AGGLUTININS, 



ingestion of the opsonised bacteria. This object, however, was 

 not attained, for agglutination was manifest in the films. Pro- 

 bably the citrate was not present in sufficient amount to prevent 

 the flocculating action of the common salt added with the corpus- 

 cular and bacterial suspensions. In the experiment, the serum 

 was diluted with four parts of 1 % potassium citrate or of normal 

 saline (0-6 % NaCl). 



Opsonisation and Agglutination with dilute serum. 



Opsonisation with undiluted sekum. 



Serum (24 hours at 20*) + suspension + 



corpuscles distributed 



Serum (24 hours at 37") + suspension + 



corpuscles distributed 



Serum, heated at 60*^ + suspension (15 



hours at 37°) + corpuscles agglutinated j (41)=26 



Serum, heated at 60° + suspension (24 



hours at 37*) + corpuscles agglutinated (50) =26 



(50)=20 

 (50) = 13 

 (35)=22 

 (30) =24 



Without discussing the action of the citrate in hindering or in 

 not assisting the opsonic, and probabl}^ also the agglutinative 

 effect, it is evident that the experiments confirm what has already 



Serum heated before dilution. 



