METHODS OF DIAGNOSIS 315 



presence of syphilis, but it is not possible at present to give an 

 explanation of the phenomenon. 



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 all the facts, there can be little doubt that leprosy in 

 certain conditions may be transmitted by direct contact, though 

 its contagiousness is not of a high order. It is not at present 

 possible to make any definite statement as to the transmission of 

 the disease by means of insects. 



Methods of Diagnosis. Film preparations should be made 

 with the discharge from any ulcerated nodule which may be 

 present, or from the scraping of a portion of excised tissue, and 

 should be stained as above described. The presence of large 

 numbers of bacilli situated within the cells and giving the staining 

 reaction of- leprosy bacilli, is conclusive. It is more satisfactory, 

 however, to make microscopic sections through a portion of the 

 excised tissue, when the structure of the nodule and the arrange- 

 ment of the bacilli can be readily studied. The points of differ- 

 ence between leprosy and tubercle have already been stated, and 

 in most cases there is really no difficulty in distinguishing the 

 two conditions. 



