448 THE BACILLUS OF TYPHOID FEVER. 



sphere vitiated in this way lost, after a time, their usual activity and 

 became emaciated, although they continued to eat greedily. When 

 these animals were inoculated with a small quantity of a culture of 

 the typhoid bacillus (0.25 to 0.5 cubic centimetre) they died within 

 from twelve to thirty-six hours. The same amount of the typhoid 

 culture injected into control animals produced no injurious effect. In 

 the animals which succumbed to typhoid infection there was found a 

 hemorrhagic enteritis, incfease in volume of Peyer's glands and of the 

 spleen, and typhoid bacilli in the blood, liver, and spleen. The char- 

 acteristic appearances of typhoid infection were more pronounced in 

 the rabbits and guinea-pigs than in rats. Similar experiments with 

 Bacillus coli communis gave similar results. The time required to 

 induce this predisposition for typhoid infection was from five to 

 seventy-two days for the rats, seven to fifty-eight for the guinea- 

 pigs, and three to eighteen for the rabbits. Alessi found that the 

 susceptibility to infection diminished after a certain time, and sug- 

 gests that in a similar way man may become habituated to breathing 

 an atmosphere containing sewer gases. 



Pus- Production by Typhoid Bacilli. The literature relat- 

 ing to the typhoid bacillus includes many observations as to its 

 presence in accumulations of pus in various parts of the body often 

 in a pure culture. It has been found in a considerable number of 

 cases of periostitis secondary to typhoid fever, in purulent syno- 

 vitis, and in abscesses in various parts of the body. 



Dmochowski and Janowski (1895), as the result of a review of the 

 literature and a painstaking experimental research, arrive at the con- 

 clusion that even in abscesses, occurring in typhoid fever cases, in 

 which only the pus cocci are found, it is probable that the typhoid 

 bacillus originated the process resulting in abscess formation. They 

 assert that the typhoid bacillus dies out in a comparatively short 

 time in abscesses which are directly due to its presence, and that 

 often it may be found in the abscess walls when its presence can no 

 longer be demonstrated in the purulent contents of the abscess cavity. 



