BACILLUS TYPHOSUS. 441 
In the febrile cases in 17 the presence of typhoid bacilli, 
often in great numbers, was demonstrated. Thus in 
these carefully followed cases the statistics show over 
80 per cent. of the febrile cases positive. The bacilli 
were isolated from these cases as early as the sixth day, 
and as late as the thirtieth day, and ina case of relapse 
on the forty-seventh day of the disease. The conval- 
escent cases gave uniformly negative results, the earliest 
examination having been made on the third day after 
the disappearance of the fever. The bacilli seemed to 
be more numerous in the stools from about the tenth or 
twelfth day on. These observations, with regard to the 
appearance of the bacilli in the stools during the febrile 
stage and their usually quick disappearance after the 
defervescence, have been confirmed by others. In 
several cases in which no Widal reaction was demon- 
strated the bacilli were isolated. From private sources 
between the seventh and twenty-first day of the disease, 
experience thus far obtained seems to indicate that the 
bacilli may be obtained from about 25 per cent. of all 
cases on the first examination and from about 75 per 
cent. after repeated examinations. In some samples of 
feces typhoid bacilli die out within twenty-four hours; 
in others they remain alive for days or even weeks. 
This seems to depend on the bacteria present in the 
feces and upon its chemical formation. Probably the 
presence of typhoid bacilli in some stools and their ab- 
sence in others must be explained largely upon the 
characteristics of the intestinal contents. The short 
life of the typhoid bacillus in many specimens of feces 
suggests that stools be examined as quickly as possible. 
In fact, unless the physician wishes to take the 
trouble to have the sample of feces sent immediately 
