BY SYDNEY B. J. SKERTCHLY. 5 



Geology and Leprosy. — We have representatives of nearly 

 :all the geological formations, and of all the rocks ; but there is 

 no relation between Leprosy and geological structure. Thus, 

 the granite of Kwantung is leprous, that of Shantung is not ; 

 the alluvium at Canton is leprous, that of Shanghai is not ; the 

 marine loams of Shantung are leprous, those of Chihli are not ; 

 and so one might go on enumerating rock after rock with the 

 like result. 



In one case there is an apparent relation between geo- 

 logical structure and Leprosy, which might be misleading if our 

 knowledge were less extensive. South Celebes is non-volcanic 

 and leprous, while the North of the Island is volcanic and free 

 from the disease. Here it would seeni that volcanic rocks enjoy 

 immunity, but when we see that the ajacent volcanic Moluccas is 

 more leprous than any part of the Archipelago, and that Hawaii, 

 entirely volcanic, is the most leprous place on earth, it is evident 

 that the nature of the rocks has nothing whatever to do with 

 the distribution of Leprosy. 



It is certain, then, that neither physiographic climate nor 

 geologic conditions have any influence upon the distribution of 

 Leprosy. 



Distribution. — By putting a red dot on a map wherever we 

 had a record of the occurence of Leprosy, and a blue one where 

 we were assured it did not exist, a Map of the Distribution of 

 Leprosy in the far East grew up ; accurate as far as it went, but 

 not complete. AVe had discovered that the general statements in 

 medical works could not be relied upon, as many places were 

 entered as leprous which we knew were free from the scourge. 

 For instance, a work on the disease of the tropics, published in 

 1894, states that Leprosy is rife throughout the length and 

 breadth of China, which indeed is the common belief among 

 Europeans even in China itself. Anotiier work on the same sub- 

 ject issued by a French physician of wide tropical experience cites 

 several of the Polynesian groups as Leprous, which we have good 

 reason to believe are not mfected. The reason for these 

 inaccuracies is probably the habit of taking the statements of lay 

 observers, who mistake some of the numerous forms of skin 

 disease, to which the islanders are very prone, for Leprosy, just 



