A defcription of a fubftance called channel,
or cat dirt, or toadjlone, containing lead
ore, and mentioned by Faujas de St. Fond,
Werner, Kirwan, &c. fhall be given in its
proper place; and on examination it will
prove to be another fubftance. Miners call
every fubftance in the limeftone ftratum,
differing in colour, &c. by thofe names;
and travellers too frequently adopt their
language, and rely on their information,
without examining the fubftances them-
felves.
No. 6. is another ftratum of limeftone,
refembling No. 4 m every particular, which
render a defcription unneceflary.
This brief account will give the reader
an idea of the general produce of Derby-
fhire. The miners have laws peculiar Mo
themfelves, of ancient date, and rigidly ob-
ferved. The lead ore throughout Derbyfliire
is fuppofed to be what is called potter’s
ore. There is not one refining furnace.
The reverberating furnace is in moft general
ufe.
The calamine and blend are got in abundance
at Bonfal, Wirkfworth, Matlock,
Caftleton, &c. being bought by the brafs
founders. There is a houfe where it is
calcined at Cromford, whence it is conveyed
to Stone, in Staffordfhire, &c. The iron
works are fmall, and not numerous, though
there be feveral at Chefterfield.
The mines throughout the county were
formerly much richer than they are now,
and produced the fineft cryftallizations.*
Near
* It is worthy of obfervation, that the veins are poorer, in
' general, the deeper they are worked, which may ferve to
fupport the opinion that veins are not formed'deeper than the
cruft of the earth ; but that 'remains fpeculative at prefent,
as does the manner in which they are filled, more efpecially
when we know fome of them are worked under an immenfe
ftratum, that does not even bear any kind of vein. Veins, although
they appear at the furface, yet they are feldom rich
until they get a confiderable depth, and where thé ftratum
forms