315 
Dr. Davy on the Geology and Mineralogy of Ceylon . 
several places ; I may mention in particular the neighbourhood of 
Atgalle and Medda maha novera, both in the Kandian provinces ; 
it occurs rather as a part of another rock, than as a great mountain 
mass. 
Felspar rock is of pretty general occurrence ; near Colombo it 
occurs bluish grey; at Trincomalie of the same colour, and also 
reddish ; and in the neighbourhood of Kandy of a very light brown. 
Adularia rock is more uncommon ; I have only met with it in one 
place amongst the mountains of Doonberava. 
Greenstone highly crystalline, nearly black from the abundance 
of hornblende it contains, occurs in the neighbourhood of Kandy 
and Trincomalie, and is one of the rocks of which Adam’s peak is 
composed. 
Quartz veins are almost every where common in gneiss ; in some 
places they are so large as to rival mountain masses ; of this des- 
cription is the quartz rock at Trincomalie, where a low hill is en- 
tirely composed of it, extending from Chapel-point to the opposite 
point on which Fort Osnaburgh is built, a distance perhaps of two 
miles. These quartz rocks stand erect, like denuded veins, very 
precipitous, and often exhibiting the appearance of buildings in ruin; 
and hence the name of Chapel-point applied to the termination of 
the ridge alluded to. The quartz is in general milk white, trans- 
lucent, full of rents, and very friable, like our annealed glass. 
Besides these, the principal, there are other varieties (if I may be 
allowed the expression) of gneiss rock. I shall mention here only 
one in particular, in which calcareous spar forms an important in- 
gredient ; perhaps the other kinds may be more conveniently con- 
sidered under the head of imbedded minerals. 
The calcareous spar variety occurs in many places, indeed I be- 
lieve in every one of the many places in which nitre is manufac- 
