1906.] Hcemolysis and the Phagocytosis of Red Blood Cells. 541 



to 1 in 100. These mixtures were placed at 37° C. for two hours. A 

 parallel series was made with serum which had been heated to 55° C. for 

 15 minutes. This was placed in the same conditions as the former series. 



This experiment shows that in the case of the unheated serum no 

 haemolysis took place in dilutions above 1 in 50 owing to dilution of tht 

 native complement and to the fact that no fresh complement was added. 

 With the heated serum there was no haemolysis, even with equal parts of 

 serum and of the suspension of corpuscles, although in such a dilution the 

 unheated, serum produced complete haemolysis. 



It was therefore decided to begin phagocytic tests with dilutions about 

 1 in 50 in the case of the unheated serum. 



Experiment to Shotv that Heating the Serum to 55° C. to 60° C. Causes a, 



Diminution of Plwgocytosis. 



Unheated immune serum was diluted with normal saline solution in the 

 proportions of 1 in 15, 1 in 20, 1 in 30. Of each of these dilutions one part 

 was mixed in a capillary pipette with one part of a 5-per-cent. suspension of 

 washed ox corpuscles and one part of washed human leucocytes, the final 

 dilutions being approximately 1 in 45, 1 in 60, 1 in 90. The tubes were 

 then placed for 15 minutes at 37° C, films being then made and stained with 

 Leishman's stain. 



At the same time series were made with portions of the serum which had 

 been heated to 55° C. and 59° C. respectively. The final dilutions in these 

 were 1 in 3, 1 in 6, 1 in 12, 1 in 24, 1 in 45, 1 in 60. A control consisted of 

 one part of - 85 saline, one part of the suspension of washed ox corpuscles 

 and one part of washed human leucocytes. 



It was found in the first few dilutions that so many red blood cells were 

 taken up by the polymorphonuclear leucocytes, that the individual 

 erythrocytes could not be distinguished and therefore the percentage of 



Dilutions of serum in mixtures. 



Result. 



1— 2 

 1— 6 

 1— 10 

 1— 20 

 1— 30 

 1— 50 

 1— 60 

 1— 70 

 1—100 



Complete haemolysis, 

 Complete haemolysis. 

 Marked haemolysis. 

 Definite haemolysis. 

 Trace of haemolysis. 

 Trace of haemolysis. 

 Haemolysis absent. 

 Haemolysis absent. 

 Haemolysis absent. 



2 E 



2 



