I Historical sketch on Immunity 527 



t coiiiirm their expectations. They found that in animals well 

 ccinated against certain bacteria (notably Gamaleia's vibrio or 

 metschuiJcovi), the blood plasma undoubtedly acquires a high 

 specific bactericidal power, but at the same time they satisfied 

 themselves that the blood, even of well immunised animals, was 

 generally incapable of killing the micro-organisms. The bactericidal 

 property, then, according to their researches, presented itself not as 

 a general character but as one of limited importance. These facts 

 even led von Behring to abandon the theory of the bactericidal 

 power of the body fiuids as an explanation of immunity. 



This theory found many warm partisans, especially at Munich. 

 Emmerich had already announced at the International Congress of 

 Hygiene, held at Vienna in 1887, that in the blood of rabbits 

 vaccinated against the bacillus of swine erysipelas an antiseptic 

 substance of remarkable activity is produced. To this, exclusively, 

 in this instance, and not to the phagocytes, he attributed the acquired 

 immunity. Later, Emmerich^ in an investigation carried out in 

 collaboration with di Mattel developed this view. We may refmin 

 from giving any account of the contents of their memoir as well as 

 from criticising their conclusions, as this has already been done in 

 Chapter ix. Let us content ourselves with stating that our o>vn ex- 

 periments, as well as those made later by Mesnil, have demonstrated 

 the inaccuracy of Emmerich's statements. 



Another Munich bacteriologist, H. Buchner, at first expressed 

 himself 2 very favourably on the theory of phagocytosis. He 

 regarded it as more capable of explaining most of the phenomena 

 of immunity than was his own older local theory. But little by 

 little he declared himself in formal opposition to the cellular theory 

 of immunity and went over to the camp of his sometime adver-[55i] 

 saries. He adopted^ the humoral theory of the bactericidal action 

 of the body fluids, upon which subject he carried out several 

 important investigations. He was able without difficulty to confirm 

 Nuttall's discovery of the disappearance of the microbicidal power 

 when the defibrinated blood was heated to 55° C, and he added to 

 this fundamental fact many others of great value. He demonstrated 

 the part played by the salts in the exercise of this bactericidal power, 

 and laid great stress on the fact that this power depends on the 



1 Fortschr. d. Med., Berlin, 1887, Bd. v, S. 663. 



2 Miinchen. med. Wchnschr., 1887. 



3 Centralhl f. Bakteriol. u, Parasitenk,, Jena, 1891, Bd. x, & 727. 



