TYPHOID FEVER. 405 



inverse ratio to the cultivation. The evident criti- 

 cism in experiments of this kind is that the results 

 are necessarily complicated by the peritonitis re- 

 sulting from the introduction of micro-organisms 

 into the cavity of the abdomen ; that the symp- 

 toms follow the injection immediately, while in 

 man there is a certain period of incubation ; and 

 that the death at the end of four days of an animal 

 very susceptible to various forms of septicaemia, 

 but which, so far as we know, never contracts 

 typhoid fever spontaneously, can hardly be taken 

 as evidence that the micro-organisms injected into 

 its peritoneal cavity were veritable typhoid germs. 

 Indeed, we cannot help suspecting that other in- 

 vestigators operating with micro-organisms from 

 other sources would have found in the symptoms 

 and pathological lesions evidence of yellow fever, 

 or of continued malarial fever, or possibly of scarlet 

 fever, without the rash ; for the absence of the 

 characteristic rash could be easily explained by 

 the fact that the integument is thickly covered 

 from sight by a heavy growth of hair. Klebs 

 also introduced cultivated typhoid organisms into 

 tne cavity of the abdomen in eleven rabbits. In 

 one only death occurred at the end of four days ; 

 and upon this slim foundation the inference was 

 made that the organisms used in the experiment 

 were veritable typhoid germs. 



" Tigri first found bacteria in the blood of a man dead 

 with typhoid fever. These organisms were also found 

 by Signol (1863) and Megnin (1866) in the blood of 



