i8 



QUATERCENTENARY STUDIES IN PATHOLOGY 



guinea-pig was employed in the same way. Haemolytic tests were 

 performed by means of Wright's tubes, and without additional 

 complement. 



After testing the serum of the guinea-pig, 3 cc. of the washed 

 corpuscles of a rabbit were injected intraperitoneally, and 5 days 

 afterwards 5 cc. of the same material. The serum was examined, as a 

 rule, daily for three weeks, from the time of the first injection, and the 

 results are to be seen in the accompanying chart. 



Fig. I. 



The method of estimation was as follows : — 



The opsonic effect of the serum of the immunised guinea-pig when 

 unheated, and when heated at 55° C. for 15 minutes, was compared with 

 that of the control animal. 



(318) 



