300 



Prof. E. Muir and Mr. C. H. Browning. [Nov. 10, 



This table shows that in the cases studied the highest dosage of the 

 complement of an animal occurs when used against its own corpuscles. 



Dosage of Immune-bodies with different Complements. 



The most striking facts brought out in this table concern the relative 

 doses of immune-bodies with rabbit's and guinea-pig's complements 

 respectively, they are (a) in the case of an immune-body acting on the 

 corpuscles of another animal (viz., ox's corpuscles), its dose with 

 rabbit's complement is practically the same as that with guinea-pig's 

 complement ; (b) when the immune-body acts on guinea-pig's corpuscles 

 its dose is ten 'times greater with guinea-pig's complement than with 

 rabbit's complement, and a converse statement obtains in the case of 

 the immune-body to rabbit's corpuscles. It is also to be noted that the 

 immune-body to ox's corpuscles does not bring about complete haemolysis 

 at all when the ox's complement is used. 



These tables supply the haemolytic doses of the different immune- 

 bodies and complements ; they do not, however, give us the facts with 

 regard to their several combinations. In illustration of this we may 

 mention that Ehrlich and Morgenroth,t finding that the dose of the 

 immune-body to rabbit's corpuscles obtained from the guinea-pig was 

 ten times higher (as shown in the table) when rabbit's complement was 

 used than when guinea-pig's complement was used, supposed that there 

 were really two immune-bodies, one present in large amount taking up 

 guinea-pig's complement and another present in small quantity taking 

 up rabbit's complement. This is manifestly a satisfactory theoretical 

 explanation, but we have to enquire whether it is supported by 

 facts. 



We shall accordingly consider the amounts of complement taken up 

 through the medium of different doses of immune-body in the several 

 cases. It will be convenient to take first the second and third sera, as 

 above arranged. The method employed for estimating the amount of 



* We have not succeeded in getting a satisfactory estimation of the dose of this 

 immune-body with ox's complement, owing to failure to remove the natural 

 immune-body for guinea-pig's corpuscles in the ox's serum. 



t Ehrlich and Morgenroth, ' Berlin, klin. Woch.,' 1900, No. 31. 



