ORIGIN OF THE DEPOSITORY COPPER ORE. 
169 
Now we have stated, that the disseminated copper ore in the regions on the 
west flank of the Ural is invariably most abundant when it is associated with the 
stems, branches or leaves of fossil trees, which formerly growing on the contiguous 
mountains, w r ere doubtless washed down from them before or during the same 
period. If this be a fair statement of the former existing conditions, we have acci- 
dentally been furnished with a modern analogy, which seems satisfactorily to 
explain why the ancient copper sources of the Ural acted so peculiarly upon the 
vegetables of that ancient eera. 
Some years ago a peat bog near Dolgelle in North Wales was found to contain so 
much copper, that certain speculators dug out the peat, and burning it, extracted 
a small quantity of ore. Fortunately for science, some specimens of the cupri- 
ferous vegetables were given to that able geologist and good chemist Mr. A. Aikin, 
who has kindly furnished us with this account of the phenomena. “ The peat 
was black, compact, and differed from the ordinary appearance of that substance, in 
containing a few small bits of bluish-green, compact carbonate of copper. The 
pieces of wood were cylindrical, each two or three inches long, and one inch or 
more in diameter, in a perfectly sound state, and seemed to be parts of a recent 
branch of oak. The transverse section of these specimens showed bluish or greenish 
stains, indicative of the presence of some salt of copper, and also grains of irre- 
gular form of copper in the metallic state. The copper contained in the bog proba- 
bly originated from copper pyrites (a mixture or compound of the sulphurets of iron 
and copper), forming a vein, or dispersed in grains in some rock so situated, that 
rain-water falling on its surface and there dissolving them, the mixed sulphurets of 
iron and copper derived from the decomposition of the above-mentioned sulphu- 
rets, might flow down into the bog. Bog-water contains vegetable acid and ex- 
tractive matter proceeding from the conversion of recent vegetables into peat, which 
substances, together with the carburetted hydrogen gas, evolved during such con- 
version, would be quite adequate to the production of metallic copper and its 
carbonate, especially when assisted by the action of the oxide of iron contained in 
vegetables.” 
This observation has thus, it appears to us, thrown a clear light on the origin 
of the most widely-spread cupriferous deposits hitherto observed in the crust 
of the globe. In no part of this vast copper region is there a trace of a true 
vein, which proceeding from beneath and traversing various strata, might be sup- 
posed to have been formed by igneous or metamorphic action upon strata pre- 
