388 
Among the more beautiful of the fossil woods are those which 
owe their metallization to copper ; the finest specimens of which 
are found in Siberia. The most accurate account of this species of 
fossil wood is furnished by M. I’Abbe Chappe d’Auteroche, who 
travelled, in the year 1 ^ 61 , into Siberia, where it is found in very 
considerable quantities, in the copper mines of the Ryphean moun- 
tains, and in the neighbourhood of Cazan. He describes dilferent 
kinds of specimens. The first kind he speaks of as copper mine- 
ralized in sand and wood. In this mine he observes that blend, 
which he at first took for iron, is distinguishable, mixed with wood, 
sand, and copper. Those parts which contain the blend and the 
sandy part, form a very hard and compact stone ; but the vegetable 
parts which it contain are so friable, as to be very easily detached ; 
the copper being discoverable in large spots of a beautiful grass- 
green colour. The wood is black, and resembles charcoal, whose 
parts are united together by some tenacious matter. The copper is 
crystallized in many parts of the vegetable substance ; its crystalli- 
zations forming small cells. These are sometimes of a clear dark or 
blackish green colour, and possess so much brilliancy, as to give 
the idea of vitreous crystallizations. The copper is blended through- 
out with a calcareous earth. The mine from which this mineral was 
obtained is to the north of Souxson. 
Another mine, to the south of Souxson, he found differed from 
the one just mentioned only in being more rich, and in the sand 
and the blend being in a less quantity. In this mine were many 
parts of an azure blue, sometimes in layers, and frequently in 
patches. Speaking of copper mineralized in wood, he says. It may 
be discovered, by the specimen which I brought, that it belonged 
to a tree A^hich w^as at least a fi^ot in diameter. The internal part 
is reduced almost to charcoal, being very friable, although the parts 
are held together by a tenacious matter. The copper is sometimes 
crystallized in little cells, resembling those of an honey-comb ; but 
