142 HAEMOLYSIS BORDET'S DISCOVERIES 



of rabbit's blood. Just as an animal which was formerly destitute 

 of that power becomes able to dissolve the cholera vibrio after 

 a few injections of that organism, so a guinea-pig, the serum of 

 which had formerly no action on the rabbit's corpuscles, acquires 

 the power of dissolving them as the result of an injection or two 

 of rabbit's blood ; hence, following the analogy with the cholera 

 vibrio, the guinea-pig is said to be " immunized " to the rabbit's 

 corpuscles, though there is here no question of the avoidance of 

 any deleterious action. Further and hence the importance of 

 these discoveries in the theory of immunity Bordet showed that 

 the laws which govern bacteriolysis by means of immune sera 

 were apparently identical with those governing Pfeiffer's pheno- 

 mena. The fresh immune serum is haemolytic ; it loses its power on 

 heating to 55 C., and it regains it on the addition of fresh normal 

 serum. Further, the action is, to some extent at least, a specific 

 one. An animal (A) injected with corpuscles of another species 

 (B) will dissolve the corpuscles of that species, and may also have 

 some action on those of animals closely allied zoologically. It is 

 evident that bacteriolysis and haemolysis are closely akin, and as 

 researches on the latter phenomena are infinitely more easy than 

 on the former, much work intended to elucidate the mechanism 

 of immunity has been carried out on red corpuscles. This is to 

 some extent regrettable, since the processes, though similar, are 

 not identical, and it is unsafe to argue from one to the other 

 without experimental verification. 



It was this analogy between bacteriolysis and haemolysis that 

 led Ehrlich to an investigation of the latter phenomenon, and 

 his researches led to a flood of new light being thrown upon the 

 subject. Ehrlich introduced fresh names for the substances which 

 Bordet had shown to be necessary for the phenomenon, and it 

 will now be convenient to give a list of the various terms which 

 the theories or caprices of various writers have applied to 

 each. 



The thermostable substance has been called : 



Substance sensibilatrice, or simply sensibilatrice. 

 Immune body. Philocytase. 



Amboceptor. Immunisin. 



Fixator. Desmon. 



Intermediary body. Copula. 



Interbody. Preparator. 



