LEPROSY. 79 
LEPROSY. 
The leprosy bacillus resembles that of tubercle, but it 
is somewhat straighter and more uniform. It occurs in 
leprous lesions in great profusion, and its discovery does 
not present any difficulty. It has never been cultivated. 
In a suspected case of leprosy, films should be made 
from the nasal discharge, for the nasal cavities are very 
frequently affected. Indeed, it seems highly probable 
that the primary lesion through which the bacilli gain 
access to the body is in the nose in most cases. A 
small portion of one of the leprous nodules may also be 
removed and films made by rubbing the cut surface 
against a clean slide. If there is an ulcer films may be 
made from the secretion from it. 
Films should be stained by the method which we 
have recommended for the tubercle bacillus. If bacilli 
are present in large quantities the case is almost cer- 
tainly one of leprosy, for tubercle bacilli are never found 
in similar situations except in scanty numbers. If a 
doubt should arise as to the identity of the bacilli, 
advantage should be taken of the fact that the leprosy 
bacillus retains the fuchsin even more firmly than the 
tubercle bacillus when exposed to the action of an acid. 
A film from the suspected material should be spread at 
one end of a slide, and some sputum known to be rich 
in tubercle bacilli at the other; the whole should be 
stained by hot carbol-fuchsin and decolorised by being 
immersed bodily in 25 per cent. sulphuric acid for half 
an hour. If the tubercle bacilli are decolorised any 
bacilli which have retained the red colour are almost 
certainly those of leprosy. If the tubercle bacilli are 
