386 Increase in the Complement-content of Fresh Blood-serum. 



The rise was complete in one and a-half hours, and amounted to under 

 70 per cent. In the second series, guinea-pig corpuscles were used along 

 with immune -body derived from a rabbit immunised to these cells. Here 

 the samples were treated as if they were samples of a normal serum, and the 

 minimal dose giving total haemolysis with constant amounts of immune-body 

 and corpuscles was determined for each. The rise of complement was not 

 complete after three hours, and amounted to more than 100 per cent., i.e., it 

 followed the rule of variation of a normal serum. The change produced 

 by immunising with ox corpuscles in this case, therefore, did not affect all 

 the complements laking guinea-pig corpuscles, but was confined to the ox -cell 

 complements. As only one such experiment was made, it is impossible to 

 say whether this is a general rule or not, or in what degree the complements, 

 which are able to take part in lysis of either ox or guinea-pig corpuscles, 

 are affected. 



Summary. 



1. The serum first separating from shed blood may differ in composition 

 from that separating later. 



2. With normal blood of rabbit or guinea-pig, the amount of haemolytic 

 complement contained in the first serum to separate is comparatively small, 

 and progressively increases in serum separating later for a period of 5 to 7 

 hours in the case of rabbit, 3 to 4 hours in the case of guinea-pig, to reach 

 a maximum 2 to 3 times as large as the amount first observed. 



3. Even after removal from the clot, the amount of complement may 

 increase in serum which separated soon after the blood was drawn, but this 

 increase is slight. 



4. This increased activity of serum is not peculiar to the haemolytic 

 complements. 



5. With the blood of immunised animals, immune-body does not increase 

 in this manner. 



6. With the blood of immunised animals, the haemolytic complements may 

 increase in amount, but this increase is not always present, and when it does 

 occur is less, and reaches its maximum more quickly than is the case with 

 normal blood. 



7. The alteration thus produced by the process of immunising probably 

 affects only the haemolytic complements related to the immunising agent, and 

 not other haemolytic complements which may be present in the serum. 



A portion of this work was done at Queensbury Lodge, Aldenham, and 

 I desire to express my thanks to the Directors of the Lister Institute of 

 Preventive Medicine, and also to Dr. Dean for the facilities afforded me 



