298 Proceedings of Royal Society of Edinburgh. [sess. 
not aid in producing the dysenteric poison. It may, of course, 
be that swampy districts exert their influence more indirectly than 
directly, for, doubtless, malaria does predispose individuals to 
attacks of dysentery, and the marshes may give rise to malaria which 
is only too often followed by intestinal disease. It has been stated 
by Annersley that dysentery rages in Bengal in the rainy season, 
and it is well known that the disease is most prevalent in lower 
Egypt at the time of the overflow of the Nile. It does not seem 
that elevation or configuration of the ground, nor the geological 
formation or the physical characters of the soil, have any connection 
with the production of dysentery. 
Although, as we have just remarked, malaria may predispose to 
dysentery, we do not find, in considering the geographical distribu- 
tion of the two diseases, that the points in which they are severally 
most virulent coincide, which one would naturally expect to he 
the case were the diseases produced by the same factors, or if 
they had a very intimate relation the one to the other. 
It can only he said, in conclusion, that contaminated drinking 
water may frequently serve to introduce the virus of dysentery into 
the system, and that it appears to he proved that a person suffering 
from the disease may introduce it into a previously healthy com- 
munity. 
X. Leprosy. 
(See Plate VII.) 
Synon . — Elephantiasis Grecorum ; Lepra ; Lepra elephantia ; 
Black Leprosy ; Bed Leprosy ; Elephantiasis tuberosa, anses- 
thetica, nodosa, mutilans, leontina, satyria; Joint Evil; the 
Myckle Ail or Great Disease ; Fr. La Lepre ; Ger. der Aussatz ; 
Scand. Spedaklalskshde ; Norway, Likpra. 
Definition . — A specific disease, endemic in many parts of the 
world, characterised by the slow development of nodular growths in 
connection with the skin, mucous membranes and nerves, and (in the 
last case) by the supervention of anaesthesia, paralysis, and a 
tendency to ulcerative destruction and gangrene (Bristowe). Two 
types of leprosy are described — the tubercular and anaesthetic 
varieties; the first variety is more frequently seen in temperate 
climates, the latter in the tropics. 
