492 THE TUBERCLE BACILLUS GROUP 
Sputum. — It should be remembered that apparently normal indi- 
viduals may infrequently have acid-fast bacilh in their sputum and, 
rarely, tubercle bacilli, without producing detectable symptoms. 
Sputum from suspected tuberculous patients may be examined directly 
by stained smears, in which case the early morning sputum coming 
from the depths of the lungs is to be employed. The caseous or puru- 
lent masses which are characteristic of tubercular sputum are removed, 
spread upon slides and examined after staining with carbol-fuchsin 
and decolorizing in the usual manner. If the result is negative, the 
sputum may be mixed with caustic soda or antiformin, shaken, and 
the sediment examined by staining with carbol-fuchsin. If this 
method proves negative, cultures from the sputum may be made 
upon Petroff 's medium. Some of the s.ediment, after washing to remove 
the solvent, should be injected into guinea-pigs. It is usually difficult 
to find tubercle bacilli in the sputum during hemoptysis, but they are 
found very frequently in the blood-streaked sputum following hem- 
optysis. 
5/00^.— Tubercle bacilli are usually not found in the peripheral 
blood. If they do occur they are there almost invariably in very small 
numbers. Occasionally positive results have been reported in examina- 
tions of stained preparations made directly from the blood when every 
precaution has been taken to preclude the inclusion of extraneous 
acid-fast organisms. It is far more satisfactory, however, to inoculate 
the blood subcutaneously into guinea-pigs. 
TJie Nasal CawY^.— Tubercle bacilli have been found occasionally 
in the nasal passages of healthy individuals, particularly those who 
have been closely in association with tuberculous patients. It must 
be remembered that the acid-fast organism described by Karlinsky 
as the "nasal secretion bacillus," is found occasionally both in the 
noses of tuberculous patients and in healthy individuals. This 
organism grows readily on artificial media and should not be confused 
with the true tubercle bacillus.^ 
Pus and Exudates. — It is frequently difficult or impossible to detect 
tubercle bacilli in the pus of cold abscesses. Material derived from 
this source is very frequently caseous, and although tubercle bacilli 
cannot be demonstrated by staining methods, the so-called Much 
granules are found occasionally, which are Gram-positive but not 
acid-fast. In order to demonstrate the infectiousness of this material 
it is inoculated into guinea-pigs. Tubercle bacilli may be found quite 
frequently in exudates, but in order to make the diagnosis reliable the 
material .should be inoculated into guinea-pigs. 
Urine.— As a rule it is difl^icult to find tubercle bacilli in urine, and 
the probability of contamination with the smegma bacillus or the 
Lustgarten bacillus must constantly be borne in mind. Sedimenting 
' Weber and Baginsky: Untersuchungen iiber das Vorkommen von Tuberkle Bazillen 
in Driizen und Tonsillen von Kindern welche sich bei der Obduktion als frei von Tuber- 
kulose erwiesen batten, Tuberkulose-Arbeiten a. d. kals. Gesundhamt., 1907, 7, 1. 
