330 Messrs. W, Phillips and 8S. Woods onthe » [Novy., 
has been decomposed by the atmosphere, and carried off by the 
rains. 
Among the loose masses on the mountain, and immediately 
around it, we found several varieties of rock which deserve 
mention. 
1, Considerable masses of arock which is extremely common ; 
it is very hard, cuts glass easily, and yields with difficulty to 
the knife ; breaks with a flat conchoidal fracture, and has much 
the aspect of flinty slate, but is frequently porphyritic from 
small imbedded masses of opaque calcareous spar, and transpa- 
rent crystals of felspar. By the assistance of a glass, however, 
this rock appears to have a somewhat granular texture, and a 
waxy lustre, and greatly resembles those of the masses inclosed 
in the rocks at the foot of the moantain, and which we con- 
ceive to be of contemporaneous formation with the rock itself. 
The colour has a tinge of green, derived, as we conclude, from 
chlorite, which appears arranged in irregular, though in some 
degree parallel lines throughout the mass, and are completely 
green by transmitted light. Other varieties do not yield to the 
knife. On the mountain, we found a loose mass consisting of 
crystallized quartz, opaque felspar (!), and chlorite in small 
quantity ; and near the foot of it a rock, not differing from those 
of the base inclosing small ovate or rather elliptical masses, of 
about the same appearance and hardness as the rock itself, 
arranged in one direction through the rock. In the wall of the 
Inn garden at Capel Curig, a fragment of considerable size of a 
rock which consisted of somewhat round masses varying in size 
from a pea to that of a cricket ball, of a substance which appears 
homogeneous, yields with difficulty to the knife, and has the 
aspect of some of the closer grained varieties of the base rock: 
these were cemented, and coated by a substance, which is soft, 
slaty, glistening, and somewhat unctuous to the touch, and 
which is manifestly talcose. In a field on the other side of the 
road to that on which “ the tap” of the Inn stands, a very 
large mass of what may properly be termed a puddingstone, 
consisting of nearly spherical masses about the size of a nut, of 
crystalline quartz, connected sometimes with calcareous spar, in 
other instances containing a substance that appears to be the 
hydrous oxide of iron; these masses are imbedded in great 
quantities in a paste, not to be distinguished from some of the 
base rocks, but very much harder, probably from the mechanical 
diffusion of silex throughout the mass. 
The continuance of rain, and the mist which unceasingly 
enveloped Snowdon, rendering it still nearly impracticable to 
ascend that mountain, we ventured to set out with the intention 
of seeing the rocks of the Pass of Llanbervis forming one of the 
grand separations of Snowdon from the neighbouring mountains. 
In this, we were only partially successful, as the rain continued 
