1906.] Haemolysis and the Phagocytosis of Red Blood Cells. 543 



These results, which were confirmed by those of subsequent experiments, 

 show that in an immune hemolytic serum the substance inducing phago- 

 cytosis of the appropriate red blood cells is partially destroyed by heating 

 the serum at 55° C. to 60° C. At the time of the experiment 0'002 c.c. of 

 the serum when fully complemented produced complete haemolysis of 2 c.c. 

 of a 5-per-cent. suspension of washed ox corpuscles after two hours at 

 37° C. and 12 hours at room temperature. 



Behaviour of the Hemolytic Amboceptor towards Scat. 



The next point for investigation was the influence of temperatures similar 

 to those employed in the phagocytic tests, on the hsemolytic amboceptor. 



Experiment. — Of the immune rabbit's serum two portions were taken, one 

 being left unheated, the other being heated at 55° C. for 15 minutes. Into 

 two series of test-tubes quantities of the serum ranging from O'Ol to 

 0001 c.c. were measured. One series then consisted of heated, the other of 

 unheated serum. All the tubes were equalised in bulk by the addition of 

 0'85-per-cent. saline solution. To each tube 2 c.c. of a 5-per-cent. suspension 

 of washed ox corpuscles were added with - 2 c.c. of fresh normal guinea-pig's 

 serum. One control consisted of 2 c.c. of the suspension of red cells with 

 0'2 c.c. of guinea-pig serum, and another of 2 c.c. of the suspension alone. 

 The tubes were placed at 37° C. for two hours and were subsequently 

 allowed to remain 24 hours at 0° C. The corresponding dilutions in the 

 heated and unheated series showed the same degree of haemolysis. 



• Result. • 



Unheated Serum. — Total haemolysis with all quantities down to 0"005 c.c. 

 Partial haemolysis with all quantities clown to - 0001 c.c. 



Heated Serum. — Total haemolysis with all quantities down to 0005 c.c. 

 Partial haemolysis with all quantities down to - 0001 c.c. 



In order to demonstrate conclusively whether there was any appreciable 

 difference between the two series, von Pleischl's haemometer was employed, 

 the last three corresponding tubes in each series being compared with each 

 other and with the guinea-pig serum control. The tubes were thoroughly 

 shaken up and centrifugalised. The supernatant fluid was then pipetted off, 

 and, if necessary, diluted sufficiently to give a reading between 20 and 60 on 

 the scale before being placed in the chamber of the instrument. The 

 reading found was then multiplied by the amount of the dilution. 



