Humboldt’s Account of the Gold and Pla-tina District of Russia.—The following account ispart of a letter from M. Humboldt, to M. Arago.—“ Wespent a month in visiting the gold mines of Borisovsk, themalachite mines of Gumeselevski, and of Tagilsk, andthe washings of gold and platinum. We were astonishe at the pepilas (water-worn masses) of gold, from two tothree pounds, and even from eighteen to twenty pounds,found a few inches below the turf, where they had lainunknown for ages. The position and probable origin ofthese alluvia, mixed generally with fragments of greenstone, chlorite slate, and serpentine, was one of the prin-cipal objects of this journey. The gold annually pro-cured from the washings amounts to 6,000 kil. Thediscoveries beyond fifty-nine and sixty degrees latitudebecome very important. We possess the teeth of fossilelephants enveloped in these alluvia of auriferous sand.Their formation, consequent on local irruptions and onlevelings, is, perhaps, even posterior to the destructionof the large animals. The amber and the lignites, whichwe discovered on the eastern side of the Ural, are de-cidedly more ancient. With the auriferous sand arefound grains of cinnabar, native copper, ceylanites, gar-nets, little white zircons, as brilliant as diamonds, ana-tase, alvite, &c. It is very remarkable, that in themiddle and northern parts of the Ural, the platinum isfound only on the western European side. The richgold-washings of the Demidov family, at Nijnei-tagilsk,are on the Asiatic side, on the two acclivities of Barti-raya, where the alluvium of Vilkni alone has alreadyproduced more than 2,800 lbs. of gold.
“The platinum is found about a league to the east ofthe separation of waters (which must not be confoundedwith the axis of the high summits), on the Europeanside, near the course of the Oulka, at Sukoi Visnin, and atMartian. M. Schvetsov, who had the good fortune tostudy under Berthier, and whose learning and activityhave been most useful during our travels in the Ural,discovered chromate of iron, containing grains of plati-num, which an able chemist at Catherineburgh, M. Helm,has analyzed. The washings of platinum at Nijnei-tagilsk are so rich, that 100 puds (about 400 lbs. Rus-sian) of sand afford 30 (sometimes 40) solotniks of pla-tinum, whilst the rich alluvia of gold at Vilkni, andother gold washings on the Asiatic side, do not givemore than 1½ or 2 solotniks in 100 puds of sand. InSouth America, a very low chain of the Cordilleras, thatof Cali, also separates the auriferous and non-platinife-rous sand on the eastern declivity, (Popayan), from thesands of the isthmus of the Raspadura of Choco, whichare very rich in platinum as well as gold.”