Dr. Davy on the Geology and Mineralogy of Ceylon . 313 
malie. I must refer to Mr. Cordiner’s “ Description of Ceylon” 
for a minute account of the hot wells ofCannia, where the water 
I allude to is found ; merely noticing what I have ascertained con- 
cerning their temperature, the nature of the air disengaged, and the 
nature of the water. Their temperature I found variable, falling 
when I was at the wells, from 107 to 103, in less than two hours, 
Without any apparent cause; the air which is disengaged from one of 
them in great abundance, I ascertained by analysis to be azote mixed 
with a little carbonic acid ; and the water itself I found nearly quite 
pure, containing no earthy or saline matter, and only very slightly 
impregnated with sulphuretted hydrogen, carbonic acid, and azote. 
The vallies are in general narrow and deep, according to the 
elevation of the hills and mountains by which they are formed. 
Without a single exception, they have always an outlet, and in con- 
sequence of this remarkable circumstance in so large an island, there 
are no lakes excepting such as have been made for agricultural 
purposes, by immense, almost incredible, human exertions ; or by 
the effect of the sea, in throwing up sand banks and stopping the 
natural exit of the waters. Of the former description of lakes, the 
largest and most remarkable occur in the northern part of the island, 
where the country at present is almost uninhabited ; the latter 
chiefly on the south-east shore ; all the salt lakes in the Mahagam 
pattoo are of this kind, and derive their salt, as I have ascertained, 
from the sea, the waves of which occasionally overrun the banks. 
I mention the circumstance because the formation of salt in these 
lakes has been considered a mystery by many. Such is a very 
general description of the leading features of the country. A poet’s 
pen could hardly do justice to its beautiful and sublime scenery. 
I should wander from my subject were I to indulge my feelings, 
and endeavour to give a picture of the charms which nature, with 
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