L E T T E R VI.
Further obfervatims made in the c-ourfe o f another lour by Don Guillermo
Bowles from Almaden to the filuer mine o f Guadalcanal.
I S E T out From Almaden for the village o f Alcocer; in
the plain there is a lead mine which has never been
worked ; after an hour’s journey we came to the mountain
o f Lares, where there are ruins of a Mooriih caille ;
here I faw for the firft time the true Spanifh emery, which
before I only knew by fpecimens in the cabinets of Paris
(a) ; the hill where it is found, is of fandftone, mixed
(a) Emery is a fort o f metallic done, found in mod, or all mines of metals, but chiefly in
thofe o f iron, copper, or gold, o f which three kinds are ufually didinguiihed; the Spaniih,
red, and common emery. The firfl fort is found in the-gold mines of Peru, and other provinces
of Spaniih America. It is judged a kind o f Marcajite of that rich metal, being fireak-
ed with little veins and Ipecks o f gold, for which reafon the king of Spain prohibits the exportation
o f it, whereby it is rendered exceedingly fcarce, to the great regret of-the fearchers
after the philofophers done, who build great hopes in the tranfmutation of this precious metal.
The red emery is found chiefly in the copper mines o f Sweden and Denmark. The.
common emery is taken out of iron mines, and is almofl the only fort ufed in England, the
confumption o f which is very conliderable amongd the armourers, cutlers, lockfmiths, glaziers,
lapidaries, mafons, and other mechanics, fome of whom ufe it to poliih and burnifli
iron and fleel works; others to cut and fcallop glafs. marble, and precious dones.
The common emery is o f a browniih colour, bordering a little on red, exceedingly hard,
and of courfe difficult to pulverize. The Engliih are the only people that have got the art of
making it into powder, which is done by mills contrived for the purpofe, and in that date
they fend it to their neighbours. Emery fufed with lead and iron hardens them. It increafes
r with
with quartz : this mineral is blackifh, refembles the poliih
given by thebloodftone,and isfo hard that it emits fire
when ftruck with fteel. The. Moors worked this mine,
but more perhaps, for the fake of the gold which it pro-
bably contains, than for any other motive ; and as their
method is not to be found in any Arabic book that I know
of, either printed or manufcript, I ihould think the following
trial might be made. Let the ore be firfl foftened
by fire and water, then expofed to the air for four or five,
months or more, that the phlogifton might feparate, leav->
ing the matter in a proper Rate to extrail the metal
by fufion. I found two forts o f emery in Spain, one in
a ferruginous ftone, and the other in fand loaded with.
iron(«z).
and heightens the weight and colour o f gold. It is ufual to mix a little *>f it with the goldi,
from Madagafcar, which is naturally pale and foft. It is brought in Engliih fhips from the
Levant, particularly from the ifland of Naxia, where, it cofis but a crown the twenty-eight quintals
• the.quintal weighing 140 lb. which is therefore what they ufually ballafi their flaps'
with.——R o lf s DnA. of Commerce.
[a) .Notwithftanding what is faid here relating to emery, Mr. Bowles, in page 364 of his
work, further informs us, that he found five forts o f emery in Spain. Firft, That o f Reipofa.'
compofed o f large grains. Secondly, O f very fmall fine grains, found at the foot o f GurfarJ
rama mountains, and ufed at St. Ildefonfo, for poliihing o f cryftals. Thirdly, The one o f
Alcocer, mentioned above, worked by the Moors, which has no grain, but on breaking the
ftone is fmooth like an haematite, and contains a little gold. Fourthly, A fpecies of emery,
as tt were, marbled in quartz, found about Molina de Aragon, and in Eftremadura, in a diflria
granted by the king, to Don Redro Rodriguez Campomanez, containing a little gold, but not
worth the expence of fearching for. ' Fifthly, Anothirfbrt diiperfeddh'many par.*' o f Spiin,'
particularly m the lordihip o f Molina, between Tortuera and Melmarcos, in loofe, black,
heavy Sones, feeming.to be the refidue; ofTome-rock or mine, and having .when pulverized’
hard pungent and mordicant particles.
Between’