1903.] liule of the Blood Fluids in Phagocytosis. 369 



The opsonic power of the blood fluids is diminished while the 

 phagocytic capacity of the W.B.C. is preserved when the blood fluids 

 and corpuscles are separately digested with Daboia venom. In the anti- 

 opsonic effect, exerted by the. venom on the blood fluids, we have 

 probably the explanation of the reduced resistance to septic invasion 

 which supervenes upon viper bites. 



It would seem probable that the bacteriolytic, bactericidal, and 

 bacterio-opsonic effects exerted by the blood fluids are each in their 

 <legree manifestations of a digestive power exerted by the blood fluids 

 on bacteria brought into contact with them. 



Lastly, a fact which has a practical importance in connection 

 with the study of immunity may be adverted to. It will be manifest 

 that we have not exhausted the study of a condition of immunity 

 when we have measured the phagocytic power of the white corpuscles, 

 and the agglutinating, bacteriolytic, and bactericidal powers of the 

 blood fluids. We must, in connection with these last, take into con- 

 sideration also the opsonic effect. 



A concrete example may be added to show the kind of elucidation 

 which may be gained from an inquiry which takes into consideration 

 also the factor last mentioned. 



The condition of immunity to staphylococcus which can be induced 

 in patients unduly susceptible to staphylococcus infections, by the 

 inoculation of properly adjusted doses of a sterilised staphylococcus 

 culture is, as was shown by one of us, associated with an increase of the 

 phagocytic power* of the white blood corpuscles, and is unaccompanied 

 by any development of a bactericidal power in the blood fluids. 



The result of the subjoined blood examinations undertaken upon a 

 patient who had been subjected to two successive therapeutic inocula- 

 tions of a sterilised staphylococcus culture, suggests that the increased 

 phagocytic power may depend upon an increase in the opsonic power 

 of the blood fluids. 



A. A. E. W.'s serum, 3 vols. ; staphylococcus suspension, 1 vol. ; 

 and A. E. W.'s washed corpuscles, 3 vols. 



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



counted and averaged) 17*4 



Tube 2. Phagocytic power (bacteria in 26 P. W.B.C. 



counted and averaged) 19'9 



}J. The patient's serum, 3 vols. : staphylococcus suspension, 1 vol. ; 

 the patient's washed corpuscles, 3 vols. 



2\tbe 1. Phagocytic power (bacteria in 15 P. W.B.C. 



counted and averaged) 35 



Tube 2. Do. do. 36 



* 'Lancet,' March 29, 1002. 

 VOL. LXXII. 2 D 



