rat 
TAB. CCXXXVI. 
Wauen on the coast at Sidmouth, I had the gratification of 
seeing the red marly sides of the cliffs or rocks beautifully, 
to appearance, veined with red and white Gypsum, from 
half an inch or less to a foot or more in thickness, for many 
feet below the summit; and from what I have been informed 
by my friend Mr. Murray, it should seem that it has much 
the same appearance at the beautiful grove near Clifton 
Hall in Nottinghamshire, the seat of Sir Jervas Clifton. 
The Marle varying between these veins, which are often 
very broad, is commonly called Red-rotten-stone-rock *, 
and is sometimes intermixed with a greenish, more or less 
indurated, Marle. The Red-rotten-stone-rock moulders on 
exposure to the air, and often leaves the Gypsum projecting 
in flattish shelves, which also sometimes moulder or fall 
down, sooner or later, according to their purity or some 
other circumstances. 
The upper specimen, figured in this plate,is from Clifton +, 
with the Marle above and below it. It is often very red, as 
if stained with the Marle: the present is a greyish speci- 
men, with the appearance of the Sulphate of Strontian found 
in a rock of the same nature in the neighbourhood of 
Bristol, where Gypsum is indeed sometimes found, but 
may be easily distinguished from that heavy earth, by its 
being so much softer and lighter. I chose this specimen 
for the sake of comparison. This finely fibrous variety, 
* The substance has nothing in common with the Rotten Stone used by 
the lapidaries, tab. 240. 
+ Ihave specimens from Forth River, near Belfast, by favour of Mr. 
Drummond. 
