198 Scientific Intelligence. — Mineralogy. 



almost universally composed of magnesian rocks ; of these the 

 most frequent is talc-slate, and less abundant are serpentine and 

 ophite. The gold occurs either disseminated in these rocks, or 

 in quartz veins which traverse them, where it is generally asso- 

 ciated with varieties of iron pyrites, which are usually aurife- 

 rous. Beresowsk is a remarkable point in the Urals : the whole 

 of the district is talc slate, surrounded by serpentine, and tra- 

 versed in all directions with an infinity of auriferous quartz 

 veins. In one place Mr Menge found gold in decayed sye- 

 nite. Erdmann, in his account of the interior of Russia, gives 

 an interesting account of the alluvial gold of that country. The 

 alluvial deposit, on the left bank of the Beresowka, is about 

 thirty feet thick, — the upper layer a loam, underneath which, 

 and forming the great mass of the alluvium, is sand, of which 

 the coarsest kinds are lowest. The gold occurs in the sand, 

 and in largest quantity, in the deepest seated, and coarsest va- 

 rieties. Two opinions as to the mode of formation of this allu- 

 vium have been proposed ; — according to the one, it is believed 

 to be derived from the neighbouring hills, because it is inter- 

 mixed with masses of quartz, and fragments of brown iron ore, 

 both of which occur in the mountains in the vicinity ; — the 

 other opinion, that it has been brought by a flood from a dis- 

 tance, receives additional support from the circumstance of it 

 sometimes containing bones of tropical looking animals, and 

 the gold being different from that of the neighbouring moun- 

 tains. This alluvium, or auriferous sand, occurs chiefly on the 

 east side of the Urals, extending from Bogislowich smelting 

 establishment, to the Polkowischen mine, an extent of 1000 

 wersts from north to south. It is very rich in the district be- 

 tween Nischni-Tagilskoi and Kuschtymskoi, and the district 

 Lenowka and Lugoowka. There is over the sand a layer of 

 peat and black earth, IJ archines thick. The uppermost bed is 

 richest in gold, the middle less so, and, at the bottom, the gold 

 is scarce. The sizes of the single pieces of gold which have 

 been met with, are worthy of being noticed. The Governor of 

 Perm presented the University of Dorpat a specimen worth 

 800 rubles. When the Emperor Alexander visited the Mines 

 of Oren burgh, he was presented with twenty-nine different 

 pieces, one of which weighed eight pounds. In the royal 



