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Antiqua
Antiqua; Auszeichnung: Kursivierung; Fußnoten mit Asterisken; Schmuck: Kapitälchen.
The following account is part of a letter from M. Humboldt to
M.
Arago:—“We spent a month in visiting the gold mines of
Borisovsk, the
malachite mines of Goumeselevski and of Tagilsk,
and the washings of gold and
platinum. We were astonished at
the petitas (waterworn masses)
of gold, from 2 to 3lbs., and even
from 18 to 20lbs., found a few inches below the
turf, where they
had lain unknown for ages. The position and probable origin
of
these alluvia, mixed generally with fragments of greenstone,
chlorite slate, and
serpentine, was one of the principal objects
of this journey. The gold annually
procured from the washings
amounts to 6,000 kil. The discoveries beyond 59 deg. and 60
deg.
latitude become very important. We possess the teeth of fossil
elephants
enveloped in these alluvia of auriferous sand. Their
formation, consequent on local
irruptions and on levellings, is,
perhaps, even posterior to the destruction of the
large animals.
The amber and the lignites, which we discovered on the eastern
side
of the Ural, are decidedly more ancient. With the aurife-
rous sand are found grains
of cinnabar, native copper, ceylanites,
garnets, little white zircons as brilliant as
diamonds, anatase,
alvite, &c. It is very remarkable, that in the middle and
northern
parts of the Ural, the platinum is found in abundance only on the
family, Nijneï-tagilsk, are on the Asiatic side, on the two
accli-
vities of the Bartiraya, where the alluvium of Vilkni alone has
already
produced more than 2,800lbs. of gold.
“The platinum is found about a league to the east of the line of
the separation of waters (which must not be confounded with the
axis of the high summits,) on the European side, near the course
of the Oulka, at Sukoi Visnin, and at Martian. M. Schvetsov,
who had the good fortune to study under Berthier, and whose
learning and activity have been most useful during our travels in
the Ural, discovered chromate of iron, containing grains of pla-
tinum, which an able chemist at Catherineburgh, M. Helm, has
analyzed. The washings of platinum at Nijneï-Tagilsk are so
rich, that 100 puds (about 400 lbs. Russian) of sand afford 30
(sometimes 50) solotniks of platinum, whilst the rich alluvia of
gold at Vilkni, and other gold washings on the Asiatic side, do
not give more than 1½ to 2 solotniks in 100 puds of sand. In
South America, a very low chain of the Cordilleras, that of Cali,
also separates the auriferous and non-platiniferous sands of the
eastern declivity (Popayan,) from the sands of the isthmus of the
Raspadura of Choco, which are very rich in platinum as well as
gold. M. Bousingault may, perhaps, already have thrown a new
light on this American formation, and his observations will derive
some additional interest from those which we have made in this
place. We possess pepitas of platinum, of many inches in
length, in which M. Rose has discovered beautiful groups of
crystals of the metal.
“As to the greenstone porphyry of Laya, in which M. Engel-
hardt has observed little grains of platinum, we have examined it
on the spot with much care, but the only metallic grains which
we have been able to detect in the rocks of Laya, and in the
greenstone of Mount Belayr-Gora, have appeared to M. Rose to
be sulphuret of iron; this phenomenon will be a subject for new
research. The work of M. Engelhardt on the Ural seemed to
us to be worthy of much praise. Osmium and irridium have also
a particular locality, not amongst the rich platiniferous alluvia of
Nijnei-Tagilsk, but near Belemboyevski and Kichtem. I insist
upon the geognostical characters drawn from the metals which
accompany the grains of platinum at Choco, Brazil, and in the
Ural.”