[ '9 1 
Many of the rocks on the roof and fides of this 
cavern are black marble, full of white fpots of a (hell- 
like figure ; and the whole neighbourhood is full of 
quarries of this beautiful done, which takes a fine 
polifh, and is ufed through the three kingdoms for 
(labs, chimney-pieces, &c. I obferved, in fome deep 
and wet parts of thefe quarries, this elegant fofiTil in 
the fird dages of its formation ; the (hells are real, but 
fo foftened by time and their moid fituation, as to 
be fufceptible of receiving the dony particles into 
their pores, by whofe cohefive quality, they in time 
become thofe hard white curls that give value to the 
marble : and it is very remarkable, and a proof that 
thefe white fpots have been real (hells, and thus 
formed, that the longer a chimney-piece or (lab is 
ufed, the more of thofe fpots ripen into view. 
I have taken many more notes of the natural cu» 
riofities in this kingdom, which I (hall be happy ta 
communicate to your refpedtable Society, if you 
think the fubjedts of fufficient importance ; and am, 
With great refpedr, 
S I R, 
Your mod obedient, 
humble fervant, 
Adam Walker. 
D 2 III. A 
