564 IDENTITY OF OPSONINS WITH NORMAL AGGLUTININS, 



An agglutination test was made at the same time, but as 

 clumping was pronounced with a dilution of 1-40, it was repeated 

 upon the following day. 



Agglutination of living Staphylococcus suspensions with normal serum 

 diluted with sodium and potassium chlorides (0'6 %). 



* The index of the undiluted serum is low. Variations in the opsonic 

 power of the same individual are of common occurrence, although Urwick 

 (Brit. Med. Journ. July 22, 1905, 173) writes, *' The opsonic power of healthy 

 people varies very slightly, or not at all, from day to day." Upon reading 

 through the papers of Wright and Douglas, one finds similar variations, 

 e.g., Proc. Roy. Soc. 74 (499) 152, patient's serum 13/4/04, (20) = 30 '3; 

 15/4/04, (20) = 10-05. Again, oj). cit. 72 (483) 363, with A. E. W.'s serum, 

 Expt. 3, tube 1, (9) = 25 -4, tube 2 (18) = 16-0. 



