BACTERICIDAL ACTION OP NORMAL SERUM 193 



on foreign corpuscles the lysin concerned has also the dual 

 constitution normal immune-body -f- complement as was 

 first shown by Ehrlich and Morgenroth, naturally raised the 

 question as to whether normal bactericidal action might not 

 be of an analogous nature, and many observers speak as if 

 this were established. At the present time it seems un j ustifi- 

 able to take up this position. No doubt in the case of the 

 bactericidal action on certain organisms the presence of 

 a natural immune-body has been demonstrated, e.g. an 

 immune-body for the anthrax bacillus in the dog's serum, 

 which can be re-activated by rabbit's complement. On the 

 other hand, various bacteria take up complement directly 

 the complement content can be practically exhausted if we 

 use sufficient bacteria and one can scarcely imagine that 

 complement taken up in this way is without effect. 



Attempts to obtain further insight into normal bactericidal 

 action have chiefly been in the direction of testing specific 

 absorbing properties, that is, treating the serum by one 

 organism and studying any changes which may result as 

 regards its action on other organisms. 



Wright and Windsor * (1902) found that treating normal human 

 serum with a small quantity of dead cholera culture removed the 

 bactericidal action for the cholera and typhoid organisms alike, 

 and that treatment with dead typhoid bacilli had a like result. On 

 the other hand, organisms which are not killed by the serum, e. g. 

 Staphylococcus aureus, did not, unless possibly to a very small extent, 

 absorb the bactericidal complement. If, however, an animal were 

 immunized against an organism, e. g. the typhoid bacillus, the increase 

 of bactericidal action which might occur towards this bacillus did 

 not obtain in the case of the cholera spirillum, there being apparently 

 a specially developed immune-body to which the increase of action 

 on the typhoid bacillus was due. Longcope 2 (1903), on the other 

 hand, found evidence of the existence of a specific complement for 

 the typhoid bacillus which was reduced in cases of the disease. He 



1 Wright and Windsor, Journ. of Hyg., 1902, vol. ii, p. 385. 



2 Longcope, ibid, 1903, vol. iii, p. 28. 



MUIR 



