1901] MICROSCOPICAL JOURNAL. 73. 
The microscopist who examined the sputum several 
times in each of these cases pronounced them not tuber- 
culous because he found no bacilli, yet the symptoms dif- 
fered in no single respect from the cases where bacilli did 
exist, and were associated with a similar train of symp- 
toms. If these were not tuberculosis, they certainly were 
not to be distinguished from it, and I treated them in the 
same way as I treated the cases where bacilli were per- 
sistently found. 
If the presence of the bacillus is the absolute and un- 
varying sign that the disease is tuberculosis, and that 
cases without the bacillus are not, then our task is easy. 
But what shall we say when two cases present themselves, 
each having all the severe and distressing symptoms that 
accompany pulmonary tuberculosis, and in one case there 
are bacilli, and in the other there are none, yet each run- 
ning a course identical in all respects. I have seen nu- 
merous cases where no bacilli were found at any time dur- 
ing the course of the disease, yet they were just as se- 
vere, and quite as fatal as cases where bacilli were per- 
sistently found. | ; 
The number of bacilli in a case, whether few or numer- 
ous, seems to have no special influence upon the severity 
or duration of the case. Cases where few or many bacilli, 
or no bacilli at all were found, were not to be distinguish- 
ed from each other. If then, cases are identical where 
bacilli do exist, with those where they do not exist, then 
we must look a little further before we say positively 
that pulmonary tuberculosis depends for its being upon 
this special germ. 
In all cases however, the pus-cell is present. Whetlier 
or not we find the bacillus, the pus-cell is never absent. 
The ulcerative nature of the disease would tell us this. 
Now this ulcerative condition of the lung we call tuber- 
culosis, seems capable of generating a certain toxic prin- 
ciple, which poison enters the lung of some other indi- 
