228 



MICROBES, FERMENTS, AND MOULDS. 



virulent properties of the microbe. Hansen considers 

 that alkalis, not acids, are the best antiseptics in this 

 disease. 



Tubercular leprosy, termed elephantiasis by the 

 ancients, is caused by tubercles seated in the skin, 

 and containing a bacillus greatly resembling that of 

 phthisis, but larger (Fig. 92). This microbe is anae- 



Fig. 92. Bacilli of leprosy, encysted in the subcutaneous connective tissue of the skin 

 (^much enlarged). 



robic, and can only live in the dermic cells, in which 

 it is encysted. Hence the treatment which experi- 

 ence, preceding the theory, showed to be the most 

 efficacious : instead of keeping the ulcers covered, they 

 should be exposed to the air and sun, often washed, 

 and kept as clean as possible. This disease, which is 

 essentially contagious, is very rare in Europe, but 

 common in Egypt and throughout Asia. 



