1904.] On Chemical ComMnation and Toxic Action, etc. 309 



It is thus seen that a comparatively close correspondence, considering 

 the conditions of experiment, is brought out between the combining- 

 ratios of the two complements in the case of these three sera. 



The chief results may be summarised as follows : 



1. In the action of a complement there are two distinct factors, viz., 

 (a) power of chemical combination, and (b) toxic action, corresponding to 

 the "haptophore " and the " zymotoxic " groups of Ehrlich ; deficiency in 

 the action of complement (or in " complementing ") does not necessarily 

 imply want of combining affinity, but may be entirely due to the non- 

 sensitiveness of the tissue-molecule to the zymotoxic group. 



2. In the case of the three hsemolytic sera studied the outstanding 

 fact is the large dose both of immune-body and of complement neces- 

 sary when we use the complement of the same species of animal as that 

 whose corpuscles are being tested. 



3. In all three cases there is a relative non-sensitiveness of the 

 corpuscles of the animal to the zymotoxic group of its own comple- 

 ment ; hence a large dose of immune-body is requisite to bring into 

 combination the amount of complement necessary for haemolysis. In 

 one case (that of the ox) there is also a deficiency in the combining 

 power of the complement with the receptors of the red corpuscles 

 united to immune-body; from the two conditions acting together 

 complete haemolysis cannot be obtained. 



4. Although differences among the molecules of the same immune- 

 serum may occur, we have found no evidence that the striking 

 differences in the dosage of the immune-body with different comple- 

 ments, and also in the dosage of various complements, are due to 

 multiplicity of immune-bodies. 



No one has yet succeeded in producing an anti-substance or immune- 

 body by injecting an animal with its own corpuscles -or cells such 

 a body as with the aid of complement would produce destruction of 

 these cells. This is manifestly a provision against self-poisoning, and 

 Ehrlich has applied to it the term autotoxicus horror. The results which 

 we have brought forward, if they were found to hold generally, would 

 go to show that even if some substance should appear which acted as 

 an immune-body, there is a provision whereby the complement of an 

 animal should produce comparatively little harmful effect. 



