t'ebu's grit, laminated With argillaceous ihif-
tus, and incumbent on the fame ftratttm;
as before mentioned..
It is by mo means my wifh to enter into
the examination of the works of literary
then With a view to confute t'hern, I merely
tVlfh to ftate ‘faCts as they appear, To as to
'prefent the fcientific with authentic 'materials.
The 'excellent Lord BaCon introduced
what is called the experimental philofophy,
in which faCts/alone are confulfed; and I
hope tO 'be ‘pardoned, if 'facrificing ‘for a
moment my veneration for thofe illuftrious
characters, I ftate the plain faCts With the
freedom Of a practical inah addicted to no
theory. I Went into a mine called D ir t -
l o w , about a'mfte eaft of Caftletdn, Where
it is laid that the'vein of l ead Ore migrates
into cat dirt, drtoadftohe ; and indeed the
mine itfelf took its name from this Cat dirt.
In
In a ftiaft, on. the left of the road going to
Bradwell, which proceeds from a large
rake vein, I went down about 40 fathom.
One fide of the vein confifted o f what the
miners called channel, cat dirt, or toadjlone^
and a part of the vein was full of that
fubftanee. t cut out fome pieces myfelf,
and directed others to he cut, all which Ï
took with më. Upon examination, this
fubftanee Was of a brownilh green colour *
interfperfed with green earth, foft, and pó-
tous. It was by no means fo hard as the
generality of limeftone, and appeared on.
the contrary to be in a ftate of decompo-
fition. It effervefeed ftrongly with acids,
and on putting a piece in a heated crucible,
I immediately perceived a ft rong finell of
fulphur. In the dark it emitted a blue
flames and burnt to a dirty red. On applying
it to the tongue, it was cauftic, and
greedily abforbed moifture.
F 2 It