530 Chapter XVI 



the fluids of the body was the primary and essential cause of immunity. 

 The phagocytes only intervened later, in order to finish the work 

 begun without their assistance. Lord Lister expressed himself^, on 

 the other hand, much more favourably on the subject of the theory 

 of phagocytosis. This observer, who is not only a great surgeon, 

 but is perhaps even more remarkable for his great powers of 

 generalisation, has paid special attention to the problem of immunity. 

 With the object of clearing up this very complicated and at the same 

 time important question. Lord Lister seized the occasion of the 

 meeting of the International Congress of Hygiene in London in 

 1891, to bring about an exchange of views between the partisans 

 of the various theories of immunity. Under his presidency he 

 devoted an entire sitting of the Section of Bacteriology to the 

 discussion of this question. Buchner presented a report^ drawn up 

 exclusively from the point of view of the humoral theory and devoted 

 to the demonstration of the slight importance of phagocytosis, and 

 also to the preponderant part played by the alexins dissolved in the 

 body fluids and circulating in the plasma of the blood. He attempted 

 to harmonise the facts on the bactericidal power of serums observed 

 in vitro with the special conditions to be met with in the animal 

 body. He specially insisted on the point that, in the blood and the 

 organs, the alexins cannot act with the same rapidity that they can 

 [554] in test-tubes containing serum. In this way he recognised that 

 between the bactericidal action in vitro and that in the body of the 

 animal, there exists a marked difference, but he would not consent 

 to attribute it in the latter case to the intervention of the phagocytes. 

 Roux^ also made a report on immunity at the same sederunt, 

 speaking very distinctly in favour of the cellular theory. A chemist 

 by inclination, he was sympathetic at first to the humoral theories of 

 immunity. Working with Pasteur, and side by side with him, Roux, 

 from the beginning of the new era of medical science, had made 

 numerous experiments on the part played by the body fluids in 

 immunity. But as the results were not sufficiently precise and 

 demonstrative they were soon abandoned. The attachment of Roux, 

 however, to the humoral theories was manifested in his work, carried 

 out in part with Chamberland*, on the subject of vaccination by 



^ " The present position of antiseptic surgery," Berlin, 1S90. 



2 Milnchen. med. Wchnschr., 1891, SS. 551, 574. 



3 A?in. de VInst. Pasteur^ Paris, 1891, t. v, p. 517. 

 * Ann. de VInst. Pasteur, Paris, 1887, 1. 1, p. 561. 



