the blue appears, by experiments, to contain a little
arfenic, filver, and copper, which, when fufed, forms
a kind of bell metal ; but the green ore has not the
leaft atom o f arfenic, and the copper mineralizes with
the white earth abovementioned, without having the
leaft part o f iron. This mine of Platilla, being of an
adventitious nature, has no great depth, and lays in
ftrata. I f the miners go deep* they are deceived; for
though the mine may dip, in a flight degree, which
perhaps in a thoufand years might form a rich vein, the
ore is difcovered, at prefent, from three, to forty feet
depth at furtheft.
Many have thought that mines are only found in barren
diftri&s; but this is an error, that of La Platilla is
a proof of it; for though the ore is fo near the furface,
the ground is covered with plants. The fame happens
in the quickfilver mine at Almaden, where they ihoot
up even within the precimfts of the furnaces, in the
fame manner as in other places, where no mines are
to be found. In that of La Platilla, where the veins
are arfenical, and not above a foot of earth over the
ore, the following trees and plants are conftantly feen;
the oak, holm, ciftus, hawthorn, juniper tree, fage
tree, dwarf ciftus, bafe horehound, bell flower, ragwort,
cornflag, orchis, Bethlem’s ftar, mujcari, or fair
haired hyacinth, milkwort, and above thirty other fpecies,
which grow in cornfields, or meadows, on the road
fide, and even on the fea fhore^ The low lands are
covered with the fame fort of grafs as the reft o f
the country, and ferve for pafture to thofe numerous
herds of cattle for which the territory of Molina is famous.
Thefe obfervations occur indifferent kingdoms. The
mines o f Sainte Marie, in France, are covered with
oak, fir, apple and pear, cherry and plumb trees,
with good pafture and corn, in a foil, about two feet in
depth, covering the moil fulphurous arfenical rocks, o f
filver, copper, and lead mines in Europe, where the very
veins are often feen above ground. An equal fertility
reigns near the mines o f Clonfthal, on the mountain
of Hartz, belonging to Hanover, with excellent
pafture. The fame happens on thofe o f Freyberg, in
Saxony, that are covered with barley, in June ; it being
a Angular fight, to fee a body of people, reaping the
corn over the heads of a thoufand miners below, bufy
in digging out paffages, and blowing up rocks, full of
arfenic, and fulphur. Some mines, without doubt, are
found under bare rocks, though this barrennefs does not
proceed from any mineral vapour, but from different
caufes, and chiefly, that, moifture, heat, and cold, have
more power on fome rocks, than over others. This is the
cafe with the great mountain of Rammelfberg, at the foot
C c 2 of