LEPROSY 69 



and vesicles may form on the papule. Unfortunately, this test 

 only indicates an existing or previous infection with tubercle, 

 and the sensitiveness may last for years after the lesion has been 

 cured. For this reason it is of comparatively little value in adults, 

 tubercle in one form or another being so common in childhood. 

 I think, however, that a very marked reaction, even in an adult, 

 usually indicates a recent infection. 



Calmette's ophthalmo-reaction may also be used, but is by no 

 means devoid of danger. 



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 can be easily detected. It can 

 only be cultivated with extreme difficulty. 



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 recom- 

 mended for the tubercle bacillus. If bacilli are present in large 

 quantities, the case is almost certainly 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 the shde, and 

 some sputum known to be rich in tubercle bacilli at the other ; 

 the whole should be stained by hot carbol fuchsin, and decolorized 

 by being immersed bodily in 25 per cent, sulphuric acid for half 

 an hour. If the tubercle bacilli are decolorized, any bacilli which 

 have retained the red colour are almost certainly those of leprosy. 

 If the tubercle bacilli are not decolorized, a fresh specimen should 

 be prepared and immersed in the acid for a longer period. 



