24 
Mr. William Phillips on the 
in flint are usually filled with the same substance ; if only adhering 
to, or partially imbedded in it, they are always I believe filled with 
chalk. 
About 40 feet below the summit of the cliff beneath the castle 
walls, lies a bed of a substance greatly resembling hard chalk marie, 
parallel to the beds of flint. It is about 18 inches thick, and is dis- 
tinguishable from below by its being of a brownish yellow colour ; 
and being harder than the chalk, it protrudes, presenting a rugged 
knotty surface. Such portions of it as fall, are collected by the lime- 
burner, who can convert them into lime only by using coal, instead 
of the ashes usually employed in the burning of chalk. Between 
this bed and the summit, a horizontal crevice is visible in the chalk, 
indicating the presence of a bed of soft chalk marie, but I had no 
opportunity of ascertaining the fact. Several other beds of hard 
chalk marie are visible in the upper chalk east of the castle, between 
the beds of flint. 
II. Bed of Organic Remains with interspersed Flints . 
When viewing the middle part of the cliff from its base beneath 
Dover castle, a singular roughness is visible. On ascending the 
green slope of some ruin, I found that it proceeded in a great degree 
from its having inclosed a vast multitude of organic bodies of 
various kinds, amongst which the remains of a few varieties of the 
echinus, and the ochreous marks of some varieties of sponge, were 
extremely frequent. In part also the ruggedness proceeded from a 
vast number of small flints irregularly interspersed through the bed, 
but which are not visible from below, because such parts of them as 
are exposed partake of the colour of the bed ; for being separate, 
$nd mostly small, they do not commonly shew any fracture. 
