104 Dr. Wright and Capt. Douglas. Action on [July 26, 



Experiment 3. 

 A. 



H. B. S.'s unheated serum 2 vols. 



A. E. W.'s washed corpuscles 2 



Suspension of heated tubercle bacilli 1 vol. 



Phagocytic index (average of 20 P.W.B.C.) 4'8. 



B. 



H. B. S/s unheated serum 2 vols. 



Suspension of heated tubercle bacilli 1 vol. 



The above were digested together for 15 mins. at 37 C. : were then 

 heated to 60 C. for 10 mins. ; and finally 3 vols. of the mixture were 

 added to 



A. E. W.'s washed corpuscles , 2 vols. 



Phagocytic index (average of 30 P.W.B.C.), 2'6. 



C. 



H. B. S/s unheated serum 2 vols. 



Suspension of heated tubercle bacilli 1 vol. 



The above were immediately after mixture heated together for 

 10 mins. to 60 C. ; and were then added to 



A. E, W.'s washed corpuscles 2 vols. 



Phagocytic index (average of 20 P.W.B.C.), 0'4. 



It will be manifest that these experiments testify to an opsonic 

 action exerted by the serum directly upon the tubercle bacilli. 



The smaller phagocytic effect recorded in each experiment in B as 

 compared with A is at present without explanation. 



The experiment next subjoined indicates that it is the potency of 

 the serum rather than the potency of the white corpuscles which 

 determines the amount of phagocytosis. In this experiment the 

 corpuscles of the tubercular patient's blood, and the corpuscles of the 

 normal blood respectively were employed in A' and A" in combination 

 with their native blood fluid. In B' and B" a reciprocal exchange of 

 Uood fluids was made. 



A'. 



Patient's washed corpuscles 2 vols. 



Patient's serum 2 



Suspension of heated tubercle bacilli 1 



Phagocytic index (average of 36 P.W.B.C.), 0'66. 



A". 



A. E. W.'s washed corpuscles 2 vols. 



A. E. W.'s serum 2 



Suspension of heated tubercle bacilli 1 vol. 



Phagocytic index (average of 32 P.W.B.C.), 3-1. 





