442 Geographical Collections. 



The washings of platinum at Nijnei-Tagilsk are so rich that \Wi 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 1^ to 2 solotniks in the 100 puds of sand. 



In South America, a very low chain of the Cordilleras, that of Cali, also sepa- 

 rates 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 ad- 

 ditional interest from those which we have made in this place. We possess pe- 

 pitas 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. Engelhardt 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 phenome- 

 non 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 iridium have also a 

 particular locality, not amongst the rich platiniferous alluvia of Nijnei-Tagilsk, 

 but near Bilembayevski and Kichtem. I insist upon the geognostical charac- 

 ters drawn from the metals which accompany the grains of platinum at Choco, 

 Brazil, and in the Ural. 



These last lines were written on the 20th August. I have abandoned the pen 

 for the last eight days, to occupy myself with taking lunar distances ; for this 

 southern extremity of Siberia, where the sources of the Obi and the confines of 

 Chinese Mongolia are found, require much attention in the geographical determi- 

 nation of places, — the rate of the chronometers alone being liable to alteration by 

 the rapidity of the journey. I have been since the 1.3th to visit the Chinese pic- 

 quet (outposts) in Dzongarie. We have been obliged to leave our carriages at 

 Oust Kamenogorsk, to make use, in these frightful roads, of the long Siberian 

 carriages, in which one lies down. But before speaking of the journey we have 

 passed in the midst of the celestial empire, I must follow the thread of our travels. 

 After having visited the north of the Ural by Verkhoturia and Bogeslavsk, taken 

 azimuths to determine the positions of the northerly peaks, visited the mines of 

 beryls and topazes at JWoursinsk, we travelled from Catherineburgh, which we left 

 on the 6th July, through Tobolsk and Jioumere, where the family of Batou-Khan 

 formerly resided. 



We intended to go directly through Omsk to Slatooust ; but the fineness of 

 the season induced us to add the Altai and the high Irtych, (3000 versts round,) 

 to the original plan of our excursion. The governor-general of Western Siberia, 

 General Villiaminov, gave us one of his aides-de-camp, M. de Yermolov, for an 

 escort. General Litvinov, who commands on the whole line of the Kirguiz, took 

 his place in coming from Tomsk to the mountains of Kolyvan, and escorted us to 

 the Chinese post. We arrived here by Kainks and the step of Baraba, where 

 the musquitoes rival those of the Orinoco, and where we were smothered under 

 masks of horse hair. Here are the romantic lake of Kolyvan, and the famous 

 mines of Schlangenberg, (in porphyry,) of Reiders, and of Siriainovski, which 

 annually yield 40,000 lbs. of auriferous silver. At Oust we had the first view of 

 the chain of the Kirguiz. 



We took the route of Baty, by the fort of Boukhtarma and of Krasnoyar, where, 

 passing the whole night of ICth to 17th August (new style) for observation, I 

 saw the singular phenomena of the polar bands. At Baty tliere are two Chinese 

 encampments, on the two sides of the Irtych, — miserable yourtes inhabited by 

 Mongolian or Cambauzian soldiers. A little Chinese temple is seen on an arid 

 eminence. The Bactrian camel with two humps pastures in the valley. 



This frontier of Mongolia supplied M. Ehrenberg with numerous plants and 

 new insects. But what renders the journey in the Altai particularly jmr."«-'- • 



