ON ANTI-IMMUNE-BODIES 111 



fugalizing and washing the corpuscles we test how much 

 complement can be taken up by the corpuscles in the two 

 series. The following is the scheme : 



\w \w \w 



A. RCs + 5 IB ! + anti-IB j + 0-3 c.c. rabbit's serum j Find how much 



55 j C is taken up. 



B (control). RCs + 5 IB j + anti-IB ; + 0-3 c.c. guinea-pig's j Do. do. 

 j serum 55 ! 



The average result may be said to be that treatment with 

 0-3 c.c. rabbit's serum 55 in A had the effect of displacing 

 sufficient anti-IB to allow the combination of fully two doses 

 of complement more than in B. 



In the control we have in other experiments replaced the 

 guinea-pig's serum 55 by ox's serum 55 and also by salt 

 solution. In all the experiments the same result has been 

 obtained, viz. the treatment with rabbit's serum 55 increases 

 the power of taking up complement, i.e. turns anti-IB (for 

 rabbit's IB) out of combination with RCs -f IB. 



The dissociation of anti-immune-body by the natural 

 immune-bodies is thus amply proved; and, as we stated 

 above, the result is more striking than that supplied by the 

 experiment showing the prevention of combination of anti- 

 immune-body by the natural immune-bodies. We cannot 

 say definitely why this should be the case ; but a possible 

 explanation might be offered by supposing that there was an 

 excess of anti-immune-body in the preventive experiment, so 

 that a portion of it was free to combine with the red cor- 

 puscles united with immune-body (RCs + IB) and thus its 

 effect was only slightly diminished. On the other hand, in 

 the dissociation experiment all the anti-immune-body is hi the 

 first place united with the corpuscles treated with immune- 

 body, and the bringing of a large amount of immune-bodies 

 (natural) into relation with it effects the separation of a 

 considerable quantity. Although we have not tested this 

 hypothesis by varying the amounts of anti-immune-body, 



