90 Chapter IV 



serum from a fowl previously treated with physiological salt solution, 

 the red corpuscles of the rabbit were dissolved without any diffi- 

 culty. Miiller explains this difference as due to the fact that the 

 serum of the treated fowl contains more complementary substance 

 than does that of the normal fowl. 



We see, then, from this example that the analysis of the pheno- 

 mena taking place in the solution of the red corpuscles by normal 

 serums is beset with very great difficulties. For this reason it is 

 much more profitable to make researches in this direction, using more 

 active serums, where the demonstration of the two substances can 

 be made simply and exactly. This desideratum has been supplied by 

 J. Bordet, when prejyarateu?' in our laboratory ; he described an easy 

 method of increasing the haemolytic power of serums. 



As stated above, guinea-pigs that have i-eceived an intraperitoneal 

 injection of goose's blood digest the corpuscles, although the peri- 

 toneal fluid exerts no haemolytic action. In vitro ^ the extract of their 

 macrophagic organs certainly dissolves the red corpuscles, w^hilst the 

 blood serum usually fails to do so. Now, if a second or a third 

 injection of goose's blood be made into the peritoneal cavities of the 

 same guinea-pigs, partial solution of the corpuscles takes place in the 

 peritoneal plasma and the serum of the blood acquires new^ properties : 

 it becomes capable of clumping the red corpuscles, that is to say of 

 agglutinating them ; afterwards it dissolves them in vitro. 



J. Bordet^ has shown that the injection of the blood of one species 

 of Vertebrate (mammal or bird) into the peritoneal cavity or under the 

 skin of an animal of a different species, always produces in the blood 

 serum of the latter the haemolysing substance. This haemolysing 

 substance is specific or nearly so, that is to say it dissolves the red 

 corpuscles of the species which has furnished the injected blood and 

 also, but more feebly, the red corpuscles of allied species. Conse- 

 quently, with guinea-pig's serum, treated with goose's blood, we 

 obtain the greatest solvent action on the red corpuscles of the goose, 

 though there is a certain haemolysis of the red corpuscles of some 

 other birds. This rule, thoroughly established by Bordet, has been 

 the starting-point for a large number of researches on haemolysis 

 [97] and amongst others of those which bear on the intermediary sub- 

 stance of normal bloods. 



Bordet demonstrated very definitely a fact of fundamental import- 

 ance — that in the blood serums of animals treated with blood from a 

 1 Ann. lie VInst. Pasteur, Paris, 1898, t. xii, p. 688. 



