408 



Messrs, Dudgeon, Panton, and Wilson. [^pi"- 26, 



possible. In our earlier experiments one part of bacterial extract was mixed 

 with two parts of normal serum and either incubated for one hour at 37° C, 

 and then one volume of the mixture added to equal volumes of leucocytes and 

 bacteria, or the extract was added after 15 minutes incubation. It was 

 found, however, that the best results were obtained by incubating for one hour 

 at 37° C. equal volumes of serum and bacterial extract, and then mixing equal 

 volumes of this with the leucocytes and bacteria. Incubation for 15 minutes 

 failed to produce the striking effects shown when longer incubation was 

 employed. 



The Action of the Endotoxic Substance on the Leucocytes. 



Owing to the limited number of experiments performed, this part of our 

 investigation is incomplete. It would appear that if the endotoxin acts 

 directly on the leucocytes at all, they are capable of complete recovery during 

 the process of washing. Our experiments fail to indicate any such direct 

 action on the leucocytes themselves. 



The Action of the Endotoxin ' Suhstance on the Serum. 



Equal parts of serum and bacterial extract were mixed together and 

 incubated for one hour at 37° C. One volume of this mixture was then 

 added to equal volumes of washed leucocytes and the bacterial suspension. 

 The experiments were completed in the usual way. In every instance equal 

 volumes of serum and normal saline were mixed and incubated for the same 

 time, and used as a control. 



The following experiments show the direct action of the endotoxin and 

 serum mixture. 



Experiment 1.* 



A. Serum saline mixture + leucocytes + 7^. ^?/067/fr?!,ra,<; — 



50 cells contained 262 bacilli ; non-phagocytic cells, 0. 



B. Serum pyocyaneus extract + leucocytes + B. -pyocyancus — 



50 cells contained 41 bacilli ; non-phagocytic cells, 30. 



Experiment 2. 



A. Serum saline + leucocytes + i?. ;?yoc?/«%e?is — 



50 cells contained 390 bacilli ; non-phagocytic cells, 0. 



B. Serum pyocyaneus extract -f leucocytes + -5. ^yocya^icws — 



50 cells contained 12 bacilli ; non-phagocytic cells, 43. 



* In this and the following experiments by "serum saline," "serum pyocyaneus 

 extract," etc., is meant one volume of a mixture of equal parts of serum and salt solution, 

 or of serum and the bacterial extract in question, after one hour's incubation at 37° C. 



