The two principal veins are attended with thofe upper
and lower ftrata o f rock, generally obferved in all veins,
to which miners have given the names o f the roof,
and the floor. At Almaden they are of black and rotten
Hate, and I have occafionally feen in them a quantity
o f cinnabar, and large round, or flat pyrites, y ellow,
and fulphurous, which, being broke with the hammer,
exhibit within fmall particles o f cinnabar. The
pyrites decompofe and diffolve, which oceafions that
vitriolic moifture which ihews itfelf in yellow fpots
on the linen of thofe who enter the mine ; and as it
comes out with lemon juice, it is evident they are martial
pyrites. There was one of thefe in the King’s former
cabinet, that weighed fixty pounds ; I colleCied fome
o f three pounds. Befides pyrites, they alfo find in
the mine, pieces of white quartz, richly ramified with
cinnabar, and light fpar, fometimes even cryftalline,
both filled with the fame matter, either lameflated
or in the form of rubies. There is alfo ilate, full of
them, and the chert, or hornjiein of the Germans^), is
ftudded with cinnabar like nail heads: even pure and native
mercury is feen in the crevices of ilate and fand-
ftone {b)>
(a) Chert. Tebdfilex. Lapis corneus. Cronfled. fe£h LXITI.
[b) Though native cinnabar has ever fo lively and red a colour, it has always a mixture
of argillaceous, or calcareous earth, or of fand; and thefe fubftances are frequently impregnated
with an arfenical taint. Even mercury, though with fq pure an appearance,
may yet be loaded with a pernicious vapour ; for which reafon, I think that native cinnabar
From
From the beft information I could get, the heirs o f
the Fuggers rented this mine till 1643, when the King
took it into his own hands, and the German miners were
difmiifed. The next year the crown allotted forty-five
thoufand trees to fupport the galleries of the mine, but
the workmen reaped no advantage from it, the timber
having been employed without art or ingenuity. The
fame year Don Juan Alonzo de Buftamante eftabliflied
the reverbatory furnaces with alludels, the Germans having
only ufed retorts, of which many fragments are ftill
to be feen amongft the rubbiih.
The direction of the hill of Almaden is from north eaft
to fouth weft,having about 120 feet elevation. I went its
whole length in four and twenty minutes, and its breadth
in fourteen. Like moft o f the hills in La Mancha, it is
compofed of two plains, whofe fummit forms a peak o f
craggy rock, but the upper part has not that perpendicular
elevation it leems to reprefent, for it forms an infhould
be baniftied frdm the ihops. A t the foot of a fteep mountain', near San Felipe, in
Valencia, I made excavations, and at the depth o f twenty-two feet, found a hard, white,
calcareous earth, containing drops o f fluid mercury. This earth, being waihed, in a neighbouring
fountain, left twenty-five pounds of pure mercury, whicfi was fent to Madrid, and
depofited in the royal cabinet of natural hiftory. A little above the fpot w'bere the mercury
was found, there were pctrifa&ions and gypfum. From exa£t refearches, we know that a bed
of cinereous clay, two feet below the furface,- extends the length o f the city o f Valencia,
from Eaft to Weft, replete with drops of mercury, which were difcovered after repeated
experiments in digging o f wells ; particularly in the houfe of the Marquis Of Dofaguas.
Thus we found it in a white calcareous earth, with petrifa&ions, at San Felipe, and behold
it in the city of Valencia, in a cinereous clay, without them !
clined