35 
Chalk Cliffs near Dover. 
externally in the form of the octohedron, but their general form 
is spherical. Others, and they are not uncommon, are in the form 
of cylinders, rounded at each termination, to which there is fre- 
quently a short stem attached ; the whole having the appearance of 
organic origin. When broken across, they are always found to 
radiate from the centre. 
Here and there appears a small bed of sponges, of which the 
ochreous forms are visible ; but this stratum contains none of the 
grey veins so numerous in the superincumbent strata. It is about 
50 feet thick. 
GREY CHALK. 
The grey chalk differs from the strata reposing on it, in being 
softer. It varies considerably in different places, in respect of 
colour and texture; being much more sandy and less compact than 
in others. A fair specimen of it yielded to my brother, by analysis, 
82 per cent, of carbonate of lime, and 18 of silex and alumine, 
chiefly of the former, and a trace of the oxide of iron. 
It first rises from the beach at the foot of the low cliff conti- 
guous on the west to that which is known by the name of Shak- 
speare’s ; but its separation from the chalk without flints is not 
at that place perfectly defined. In less than a quarter of a mile 
beyond the place at which it rises from the beach, the two strata 
are very distinct ; the white being separated from the grey by some 
very thin beds of a sandy appearance and yellowish colour. As 
the grey chalk rises, its colour becomes deeper, and it is here and 
there so extremely soft, that the rain in descending the cliff, has 
carried down and deposited at its base considerable quantities. It 
is in these places particularly, that beds of sandstone from 1 to 4 
or 5 inches thick, and extremely hard, take their course parallel 
