1909.] 



Intracellular Constituents of Bacteria, etc. 



335 



gramme) were injected, and the opsonic index was determined 15 hours, 

 20 hours, 24 hours, 48 hours, and 72 hours, and five days and seven days 

 after inoculation. The results are given graphically in Chart IX of the 

 opsonic indexes. 



Chart IX. — To ascertain extent of " Negative Phase " with large doses of Staphylococcus 



Vaccine and Endotoxin. 

 Eabbit XX received 1"5 c.c. (= 15 x 10 s cocci = 0"15 milligramme) vaccine. 

 Babbit XXI received 1*0 milligramme endotoxin. 



Front these experiments (Chart IX) it would appear that the vaccine 

 (Rabbit XX) produces a decidedly greater negative phase at the twentieth 

 hour after injection than the endotoxin does (Eabbit XXI), although, weight 

 for weight, six and a half times as much active material was administered 

 in the case of the endotoxin than in that of the vaccine. The results of 

 this experiment (and also of those detailed in Sections B, C, and D) suggest 

 that the endotoxin induces decidedly less negative phase than a vaccine. 



I have to express my best thanks to Mr. Wellcome for the facilities he has 

 afforded me at the "Wellcome Physiological Eesearch Laboratories for carrying- 

 out the greater part of this work, and to Mr. E. Thompson, Laboratory 

 Assistant, on whom much of the labour of making the counts of the opsonic 

 determinations has fallen. 



(Part of the expense incurred in this work has been defrayed by a grant 

 from the British Medical Association.) 



