TUBERCLE. 75 
mistakes in this country; it is recognised by the fact 
that it is straighter and more uniform than the tubercle 
bacillus, and by the fact that it resists decolorisa- 
tion more powerfully than the tubercle bacillus. The 
smegma bacillus may occur in the urine and lead to 
mistakes unless the sample examined was drawn off per 
catheter. It is distinguished by the fact that it is 
readily decolorised by alcohol (absolute alcohol or 
methylated spirit) while the tubercle bacillus is not. 
In staining a film from the urine we decolorise in spirit 
for a minute after the acid and before the methylene 
blue, 7.2, between stages 3 and 4 in the above 
description. 
In searching for the tubercle bacillus the } in. lens 
will serve, though an oil immersion lens is an ad- 
vantage. 
METHOD OF COLLECTING THE SPUTUM. 
This is of some importance, and the method recom- 
mended should be carried out in all cases. 
Get the patient to wash out his mouth thoroughly 
with warm water before going to bed. Let him spit 
into a clean bottle, jar, or tin, and employ only the 
sputum coughed up before food is taken in the morning. 
METHOD OF PREPARATION OF THE FILM. 
Sputum.—Pour the sputum into a watch-glass and 
place the latter upon a dark surface. Examine it 
closely, looking out for small yellow particles; these 
consist of caseous material and will probably contain 
