vitriol, which we call copperas, forms blue cryftals, with
copper, and vyhite cryftals, or allum, when united with
argillaceous earth, and o f the fame colour when it dif-
folves zinc, and produces yellow, when it coagulates
with the phlogifton of common fulphur, which abounds
fo frequently in the three kingdoms of nature. The hioft
remarkable circumftance, is to meet thefe colours in the
Bifcay mines, which neither contain copper, allum, zinc,
fior fulphur ; nor is it an eafy matter to account for it,
-without fuppofing that the pure elementary, water, has a
part in compofing thefe cryftals, and that its evaporation,
either by heat, or air, alters the confiftency, and
deftroys the green colour of the vitriol of the iron,-taking
away that proportion of water, which constituted it,
.and that as foon as it'lofes it, it begins to change colour,
and paiftng through the various tints of green, and yellow,
terminates in white, when all the water is gone:
-when it is come to that ftate, and has a refemblance to
flour, it is called fympathetic powder, on account of its
Jtyptical quality, fo Teadily {launching the blood, in
hemorrhages, and curing of wounds. | Whoever choofes
to verify this theory, need only-to pour water on this
white powder, and he will find that it eryftallizes anew
into green. I f it be afked, why thefe matters do not
mnite, and form fulphur, when there is fo much, acid,
and iron in thefe mountains;, and the iron contains fo
inuch phlogifton? I anfwer, that for this event to take
place,
place, the vitriolic acid, and the phlogifton, Ihould be perfectly
concentred, and dry; whereas the reverfe happens
in thefe mountains, where they are fo overwhelmed with
moifture, that the abundance of this acid, has perhaps
been the Caufe, of many of the mines about Bilbao, being
neglcded, as o f courfe they would yield fo brittle an
iron. This- then would be the time to ufe a calcareous-
fubftance, to corred this defed, I t is for this reafon-;
the Swedifti iron is preferred to the Spaniih, as the latter
is fo apt to redfeai, that is, to crack, between hot and cold.
At a fmall diftance from this great ferruginous rock, an
engineer lately cut away a confiderable part of the hill,
to improve the public walks, near the town of Bilbao,
and as he made a perpendicular cut o f about eighty feet
depth, he difcovered a vein of iron ore, lying in perfect
ftrata, which, at times, dipped in adired line, and at others,
obliquely, bearing feme fimilitude to the roots o f a tree,
oecafionally of an inch diameter, or theiize o f one’s arm,
with infinite variety o f ramification, according to the
more or lefs refiftance o*f the earth, to the paffage o f
water there being no doubt of this mine being alluvial.
Here the very circumftance has happened, which.
Don Antonio de Ulloa, judiciouily imagined, would
follow in the great hill of Potofi, were it poflible today
it open.and examine its contents.
It