80 PROPERTIES OF H^MOLYTIC SERA 



complement. In both cases the haemolytic dose of immune- 

 body is ten times greater when the complement of the 

 animal whose corpuscles are being tested is used than when 

 the complement of the other animal is used. This will be 

 seen from the table. In this case, also, the dose of rabbit's 

 complement is high, just as in the previous case the dose 

 of guinea-pig's complement was. How much rabbit'^ 

 complement is taken up when multiple doses of immune- 

 body are used ? The scheme of experiment is : 

 Rabbit's O + n IB + x rabbit's C | + Ox's O + IB. 



The following are some of the results * 

 Experiment LXIL 



1 D of IB takes up 0-14 c.c. rabbit's C. 

 10 1-16 



Experiment LXIII. 



1 D of IB takes up 0-22 c.c. rabbit's C. 

 10 1-12 



Experiment LXVI. 



1 D of IB takes up 0-086 c.c. rabbit's C. 

 5 0-55 



10 0-9 



Dose of rabbit's C with rabbit's corpuscles = about 0-6 c.c. 

 ' 1 D ' = M.H.D. of IB along with guinea-pig's C. ' 10 D ' = 

 M.H.D. with rabbit's C (vide tables, p. 72). 



It will be seen that there is no lack of combining-power 

 on the part of rabbit's complement, and that the amount 

 increases with the amount of immune-body, though con- 

 siderable deviations from exact arithmetical proportions are 

 met with. Sometimes more, proportionately, is taken up 

 by ten haemolytic doses than by one hsemolytic dose, some- 

 times less ; we have met with the former phenomenon in 

 several other experiments than that quoted, and are not 

 able to give at present an explanation of it. Another 

 point is that the hsemolytic dose of immune-body (expressed 



