1909.] Hcem-agglutinins, etc., in the Blood. 



73 



conversely, normal serum was allowed to act in the presence of immune 

 leucocytes obtained from various diseases. 



It was thought that the different results which were obtained when the 

 serum from one case was mixed with the red cells and leucocytes of another 

 might be due partly to haemolysis or to a process of de-opsonisation owing to 

 the mixture of serum with suitable red cells. Kobert Muir and Martin, in 

 a paper published in the ' Proceedings of the Eoyal Society,'* showed that 

 a serum could be largely de-opsonised by saturation with various substances, 

 among them suitable red blood corpuscles. In their experiments suitable 

 red cells and serum were allowed to remain in contact at 37° C. for a con- 

 siderable period of time. 



If the various results obtained by allowing a normal serum to act in the 

 presence of normal leucocytes and red cells, as compared with the immune 

 serum with normal red cells and leucocytes, were partly dependent upon 

 a htemolytic action, this change would have to take place during a period of 

 15 to 20 minutes, because this is the time commonly employed for the 

 incubation of phagocytic mixtures. The prolonged periods of time as used 

 in saturation experiments would be unsuitable to explain the different 

 results obtained in so short a period of incubation as 15 to 20 minutes. 



In every observation on phagocytosis carried out in these experiments records 

 were also made as to whether hccm-agglutination and haemolysis occurred. 



Attempts were made to ascertain whether it was possible to prove the 

 actual part played by haemolysis.t The technique employed to elucidate 

 these points was as follows : — 



The serum which was being examined for its power of exciting 

 phagocytosis was saturated with the washed red cells belonging to the 

 phagocytic mixture ; the whole was placed in glass tubes sealed and 

 incubated at a temperature of 37° C. for 15 minutes. The tubes were then 

 centrifugalised at high speed and the clear fluid was compared with the 

 serum previous to saturation. 



Control experiments were conducted with a mixture of serum and red 

 cells in which no agglutination or htemolysis occurred. The first series of 

 observations conducted along these lines concerns the blood obtained from 

 apparently healthy individuals. 



Normal serum (L) + normal leucocytes {R)-\- Staphylococcus aureus, 

 50 cells = 270 cocci. 



* ' Eoy. Soc. Proc.,' B, vol. 79, May, 1907, Robert Muir and Martin. 



t It has been found from experimental observations that the highest phagocytic 

 readings occur with specimens of blood in which hcemolysis can be demonstrated, 

 ■although notable exceptions do occur. 



VOL. LXXXII. — B. G 



