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



by Nuttall* in Fliigge's laboratory, that the staphylococcus offers 

 resistance to the bactericidal action of the blood fluids. Two years 

 afterwards the observations of Nuttall, which had reference to the 

 blood of animals, were extended by Sternf to human blood. The 

 methods employed by Nuttall and Stern alike did not, however, permit 

 of a comparatively small bactericidal action being distinguished from 

 a complete absence of bactericidal action. 



The question as to how far the staphylococcus offers resistance to the 

 bactericidal action of human blood was reinvestigated by one of us, 

 the results being published (a) in a paper dealing with anti-staphy- 

 lococcus inoculations!, and (bj in a paper written in conjunction with 

 Captain F. Windsor, I.M.S., on the bactericidal action exerted by 

 human blood upon a variety of pathogenic micro-organisms. It was 

 established in the researches here in question, which were conducted 

 with the more delicate methods of investigation set forth in the ' Pro- 

 ceedings of the Royal Society '|| and in the Lancet 'H respectively, (a) 

 that normal human blood does not exert upon the staphylococcus any 

 bactericidal action whatever, and (b) that anti-staphylococcus inocula- 

 tions do not lead to a development of any bactericidal power in the 

 blood.** 



Qpsmic Action. It having become evident in the course of these 

 researches that the effect of anti-staphylococcus inoculation is not to be 

 found in a development of bactericidal properties in the blood . fluids, 

 attention was directed to the measurement of the phagocytic power of 

 the blood. Taking to aid the method of phagocytic estimation devised 

 by Major W. B. Leishman, R.A.M.C.,itwas ascertained that successful 

 immunisation against staphylococcus goes in every case hand in hand 

 with the acquirement of increased phagocytic power. 



Certain difficulties having suggested themselves in connection with 

 the attribution of this result to a "training" of the white blood corpuscles 

 we addressed ourselves to a further investigation of the phenomena of 

 phagocytosis. 



In the course of this investigation! t it became clear that phagocytosis 

 of bacteria is dependent upon an effect exerted upon the bacteria by 

 the blood fluids. We spoke of this effect as an opsonic effect. 



In a second research, J J in which we extended our previous observations, 

 on the opsonic power of the blood fluids, we showed that the increased 



* Nuttall, ' Zeitschrift f. Hygiene,' 1888, vol. 4. 



f Stern, ' Verhandlungen des IX Congresses f . Innere Medicin,' 1890. 

 I Wright, ' Lancet,' March 29, 1902. 



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

 || Wright, 'Koy. Soc. Proc.,' vol. 71, 1902. 

 1 Wright, ' Lancet/ December 1, 1900, and March 2, 1901. 



* Vide ' Journal of Hygiene ' (loc. citj, Tables VII and VIII. 

 ft Wright and Douglas, 'Koy. Soc. Proc.,' 1903, vol. 72. 



tt Wright and Douglas, ' Eoy. Soc. Proc.,' 1904, vol. 73. 



