BY R, GREIG SMITH. 



297 



Washed leucocytes ivith bacteria aggJutinatedhy heated serum. — 

 This was the same serum as in the previous experiment. 



Normal bacteria No phagocytosis. 



Bacteria treated with heated active serum — 



15' at 60". 1 : 75. ... Phagocytosis. 

 30' at 65 ^ 1:25. .. 



A week later, a fresh supply of active serum was obtained from 

 the same patient, and it was found that the limiting ratio had 

 risen from 1:75 to 1:250. Upon heating the serum, much of the 

 agglutinating power disappeared and the limit became 1 :45. 



Bacteria treated with heated active serum — 



15' at 60°. 1:25. ... Phagocytosis. 

 1:75. ... 

 The experiment was made in triplicate with identical results. 



Washed leucocytes with other races of Bact. tyi^hi. — Hitherto the 

 race of Bact. tyj?hi that had been used was marked "Newcastle," 

 which along with othets marked "Pasteur Institute" and "Jenner 

 Institute of Preventive Medicine," had been obtained from Dr. 

 Tidswell, of the Board of Health, Sydney. The "Newcastle" 

 race had been employed because it appeared to be least affected 

 by the immune bodies in normal serum. But as the race of 

 bacterium might influence the phagocytic effect, the other races 

 were tested. In this and all future experiments, heating means 

 an exposure to 60° for 15 minutes. 



