1903.] Hole of the Blood Fluids in Phagocytosis. 359 



Procedure No. 2, Employed where we Desire to Elicit Separately the R61e of 

 the White Corpuscles and the Blood Fluids in Phagocytosis, and to 

 Study the Effect Produced by Experimental Modifications of one or other 

 of these Elements Separately. 



Having provided ourselves with a capsule with a recurved limb 

 (such a capsule has already been figured in a previous communication),* 

 we introduce into it such a quantity of mercury as will fill it to about 

 one-third of its capacity. Having marked off by a pencil mark (made 

 with a glass writing pencil) the level at which the upper surface of 

 the mercury stands, we displace the mercury in such a manner as to 

 cause it to occupy the middle instead of the lower region of the 

 capsule. We again mark off on the outside of the capsule the upper 

 limit of the mercury. 



Then, emptying out this last, we bend round in the flame the curved 

 limb in such a manner as to cause it to lie in the plane of the equator 

 of the capsule. This enables us to siphon into it from a watch glass, 

 filled and placed ready to hand, the citrate of soda solution. We 

 introduce of this solution such a quantity as suffices to fill the 

 capsule up to the level of the first pencil mark. This done, we draw 

 blood from the finger and let it run into the capsule until the combined 

 volume of citrate of soda solution and blood attains the level of the 

 second pencil mark. 



Having sealed up the upper orifice in the flame rarefying as we do 

 so the air in the interior of the capsule by the application of warmth 

 we shake up the contents and suspend the capsule by means of 

 its curved limb into the receptacle of the hand centrifugal machine. 



When centrifugalisation has caused the corpuscles to settle to the 

 bottom, we pipette off and reserve the supernatant citrated plasma 

 and replace it by physiological salt solution. In conducting this 

 last operation we employ a capillary pipette, and we carry down its 

 orifice to the very bottom of the capsule in such a manner as 

 effectively to mix up the corpuscles and the newly added fluid. 

 We wash and centrifugalise in this manner three times. The upper 

 layers of the corpuscular deposit, containing as they do a large 

 proportion of white corpuscles, supply the phagocytes required for 

 experimentation. 



In the experiments set forth below we mixed in each case three 

 volumes of the upper layers of the washed corpuscular deposit, with 

 three volumes of blood fluid, and one volume of a staphylococcus 

 suspension, containing generally from 7000 10,000 million staphylo- 

 cocci per c.c. The mixture of corpuscles, blood fluid and staphylo- 

 cocci was kept in each case for 15 minutes at a temperature of 37 C., in 

 order to give opportunity for the occurrence of phagocytosis. 

 * Wright, ' Roy. Soc. Proc.,' vol. 71, 1902. 



