THE BACILLUS OF TYPHOID FEVER. 



443 



usually within forty-eight hours, and that the bacillus may be re- 

 covered from the various organs, although it is not present in the 

 blood. But death does not always occur from intravenous injections, 

 and subcutaneous or intraperitoneal injections in rabbits are usually 

 without result. Subcutaneous injections in mice proved to be fatal in 

 ten cases out of sixteen inoculated by A. Frankel. Seitz, by following 

 Koch's method i. e. , by rendering the contents of the stomach alka- 

 line, and arresting intestinal peristalsis by the administration of 

 opium obtained a fatal result, in a majority of the guinea-pigs experi- 

 mented upon, from the introduction of ten cubic centimetres of a 

 bouillon culture into the stomach through a pharyngeal catheter. 

 We may remark, with reference to these results, that while they show 

 that cultures of the typhoid bacillus have a certain pathogenic power, 



FIG. 111. Section through wall of intestine, showing invasion by typhoid bacilli. X 950. 

 (Baumgarten.) 



they also show that the animals experimented upon frequently re- 

 covered after comparatively large doses, and that the typhoid bacil- 

 lus is not pathogenic in the same sense as are those microorganisms 

 which, when introduced into the body of a susceptible animal in very 

 minute amount, give rise to general infection and death. On the 

 other hand, a fatal result depends upon the quantity of the culture 

 introduced in the first instance, rather than upon the multiplication 

 of the bacillus in the body of the inoculated animal. This view is 

 confirmed by the experiments of Sirotinin, which show not only that 

 a fatal result depends upon the quantity injected, but also that a 

 similar result follows the injection of cultures which have been ster- 

 ilized by heat or filtration. The pathogenic action, then, depends 

 upon the presence of toxic substances produced during the growth of 

 the bacillus in artificial culture media. The researches of Brieger, 

 heretofore referred to, show the presence in such cultures of a toxic 

 ptomaine his typhotoxine to which the pathogenic potency of these 



