ORE OF PLATINUM AND ITS ORIGIN. 
483 
nated 1 . All the coarse detritus had evidently been forced hither by the same waters 
which entombed the mammoths ; for the present stream can scarcely remove a 
pebble the size of an inch. In following this rivulet and the river Kakva, into 
which it falls, to the lower grounds of Siberia, the remains of mammoth, rhino- 
ceros and Bos Urus multiply, and in the old alluvium on the banks of the rivers 
Pellim and Tavda, both tributaries of the Tobol, are very abundant. 
Origin of the Ore of Platinum, and probable diffusion of that Metal as well as Gold 
through certain rocks. — We have just spoken of the diffusion of gold ore through 
certain rocks of the North Ural. Even at the moment when we made the memoranda 
on the Peshanka, and saw how completely the auriferous sand at that spot seemed 
to be simply the disintegrated surface of the subjacent rock (a sort of syenite or 
“ granite pourrie”), we could not doubt of the likelihood of such a phenomenon. 
Since that time Professor Hoffman has ascertained, that in a considerable region 
of eastern Siberia, the gold is really disseminated, not only through granitic and other 
igneous rocks, but also through large bodies of clay slate®. In this respect, indeed, 
there is nothing in the dissemination of the gold, which is in any respect dissimilar to 
what is known of the diffusion of magnetic iron, pyrites and various other minerals, 
through the substance of rocks, both igneous and sedimentary. The fact is, then, 
that though gold has frequently been, and is for the most part, formed in quartzose 
and other veins which have either penetrated or been separated from the mass of 
the formation (and off these the Ural affords countless examples) , it has also been 
diffused in some tracts throughout the whole body of the rock, whether of igneous 
or aqueous origin. 
Though ores of platinum are found in the alluvia of the Ural chain in various 
parallels of latitude, it is only within the territories of the Demidoff family that 
they are still worked. After an examination of the greater number ot the platinum 
works belonging to Nijny Tagilsk, all of which lie on the western slope of the 
Ural-tau in that parallel, M. G. Rose had shown, that in one only of the numerous 
masses of alluvia was any gold mixed with it, and that in no instance could he 
detect any veinstones of quartz or other fragments of rocks, nor of magnetic iron 
' Since the year 1829, when it was discovered, this mine of Peshanka had yielded, to 1840, or in eleven 
years, 250 poods or 10,000 Russian lbs. of gold. 
2 For an account of the enormous increase of gold derived from the eastern governments of Siberia in 
the last two years, with speculations thereon, see Mr. Murchison’s Address to the Royal Geographical 
Society (Journal Royal Geog. Soc. Lond. vol. xiv. part i. p. lxvi.). An extract will be given in the Ap- 
pendix. 
