3G3 Dr. A. E. Wright and Capt, S. E. Douglas. [Sept. 1, 



A. 4 vols. of the above mixture heated to 60 C. for 20 minutes, 

 then cooled and added to 3 vols. of S. E. D.'s corpuscles. 



Tube 1. Phagocytic power (bacteria in 20 P.W.B.C. 



enumerated and averaged) 13*5 



Tube 2. Do. do. 17 -1 



B. 4 vols. of the above mixture added directly to 3 vols. S. E. D.'s 

 corpuscles. 



Tube 1. (Bacteria in 15 P.W.B.C. enumerated and 



averaged) 40'6 



Tube 2. Do. do. 44*5 



EXPERIMENT 3. 



S. E. D.'s uuheated serum, 3 vols. ; 1 vol. of staphylococcus sus- 

 pension ; digested together 1 hour at 37 C. 



A. 4 vols. of the above mixture heated to 60 C. for 10 minutes, 

 cooled and added to 3 vols. of S. E. D.'s corpuscles. 



Tube 1. Phagocytic power (bacteria in 16 P.W.B.C. 

 enumerated and averaged) 15*1 



B. 4 vols. of the above mixture added directly to 3 vols. of 

 S. E. D.'s corpuscles. 



Tube 1. Phagocytic power (bacteria in 16 P.W.B.C. 

 counted and averaged) 22*1 



In conclusion we would briefly refer to the following points : 



The opsonic power of the blood fluids disappears gradually on 

 standing, even when the serum is kept in a sealed capsule sheltered 

 from the light. 



After 5 or 6 days we have found the opsonic power of the serum 

 kept under these conditions to stand at little more than half of what 

 it was originally. 



The opsonic power of the blood fluids is but little impaired by the 

 action of heat until these have been exposed to temperatures above 

 50 C. The following are the results of a typical experiment : 

 Phagocytic power obtained with the serum before exposure to heat, 

 12 -7 ; with the same serum heated for 10 minutes to 45 C., 13*1 ; 

 with the same serum heated for 10 minutes to 50 C., 10'2; with the 

 same serum heated for 10 minutes to 55 C., 5*7. 



The opsonic power of the serum is diminished when this last has 

 been digested with typhoid bacteria. This " anti-opsonic " effect may 

 compared with the " anti-bactericidal " effect* obtained on digesting 

 the serum with typhoid or cholera cultures. 



* Wright and Windsor, 'Journal of Hygiene,' vol. 2, No. 4, Oct., 1902. 



