266 LEPROSY. 



which are followed by a fresh outbreak of nodules, and it 

 would appear that especially at these times multiplication of 

 the bacilli takes place more actively. 



The facts stated with regard to cultivation and inocu- 

 lation experiments go to distinguish the leprosy bacillus all 

 the more strongly from other organisms. Some have 

 supposed that leprosy is a form of tubercle, or tubercle 

 modified in some way, but for this there appears to us 

 to be no evidence. Both from the pathological and 

 from the bacteriological point of view the diseases are 

 distinct. It should also be mentioned that tubercle is a 

 not uncommon complication in leprous subjects, in which 

 case it presents the ordinary characters. 



The mode by which leprosy is transmitted has been the 

 subject of great controversy, and is one on which authorities 

 still hold opposite opinions. Some consider that it is a 

 hereditary disease, or at least that it is transmitted from a 

 parent to the offspring ; others again that it is transmitted by 

 direct contact. There appears to be no doubt, however, 

 that on the one hand leprous subjects may bear children 

 free from leprosy, and that on the other hand, healthy 

 individuals entering a leprous district may contract the 

 disease, though this rarely occurs. Of the latter occurrence 

 there is the well-known instance of Father Damien, who 

 contracted leprosy after going to the Sandwich Islands. In 

 view of the fact that we must regard the bacillus as the 

 cause of the disease, it is highly probable that in certain 

 conditions it may be transmitted by direct contact, though 

 its contagiousness is not of a high order. 



In leprosy, therefore, there is an organism which is 

 invariably present in the disease, and has a special relation 

 to the changes in the tissues. This organism can be 

 distinguished from all other known organisms, and is found 

 in no other condition. Further, all the tissue changes in 

 leprosy can be readily explained by the presence of a low 

 form of irritation, such as is afforded by this organism. 

 The evidence stated must be accepted as to its being the 

 cause of the disease, though absolute proof is still wanting 



