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 



