32 6 Dr. Davy on the Geology and Mineralogy of Ceylon . 
of rivers, which flow only during the rainy season, and are dried 
up soon after this season is passed. Agaric-mineral I have met with 
in small quantity between Kandy and Hangranketty. 
The only remaining feature that I am acquainted with in the 
geology of Ceylon, not yet considered, is the recent formation of 
rock before alluded to that occurs on the shores of the island. It 
is sandstone rock, which has formed in many places below high 
water mark, extensive horizontal beds : the rock is in general hard 
and compact, of a light yellow or grey colour. It consists of sili- 
ceous sand and minute fragments of shell. Submitted to chemical 
analysis, its constituent parts appear to be the same as those of the sand 
of the contiguous shore, and their proportional quantities similar. 
What the cementing principle is I have not ascertained ; there is no 
reason to consider it iron ; in all probability it is the same as that of 
a similar formation in the west of Cornwall. It is remarkable, that 
this rock does not form in sheltered situations ; on the contrary, 
where the sea breaks with uncommon violence. From the compo- 
sition of the rock and its situation, there is good reason to believe, 
not only that it is very recent, but that the process of consolidation 
is still going on. How far this sandstone formation extends along 
the shore I have not yet been able to determine ; I have found it 
near Colombo, at Negombo, and in many places between Point de 
Galle and Matura : further, I have seen specimens of a similar rock 
from the northern shores of the island. 
I have been asked often, “ are there no volcanic remains, or indi- 
cations of volcanic action in Ceylon ? ” I have sought for them, 
but hitherto without- success. Trincomalie is the only part of the 
island that I have yet seen that excites even the suspicion of volcanic 
action. I have mentioned one circumstance that may lead to this 
suspicion, viz. the hot-wells of Cannia ; and I have alluded to ano- 
