Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/172

 160 a fact nearly similar, observed in the coal strata near Hainchen. He also saw a vein at Joachimstal, entirely filled with pebbles. Now, how is it possible that these stones could find their way into the interior of the veins, if these had not been originally open at the top?

Though according to the theory of Werner, the spaces of veins were immediately filled up by precipitations from the same solutions which, by previous precipitations, had formed the mountains, it does not, I think, follow as a necessary consequence that beds and veins are exactly of the same age. The difference which I conceive exists between them is in the mode of their formation.

Beds of ore being now covered by strata of rocks, in a manner conformable with those on which they have been deposited, it follows, that the elements of both were all held in solution at the same time, but that by a play of affinities, which tended to unite together similar particles, sometimes precipitates of the one, and sometimes of the other, took place, by causes which are yet unknown to us; but since they are deposited alternately we may safely say that they are coeval. Veins on the contrary, having been originally fissures, which could not be formed until after the retreat of the waters, when the mass of the mountain was in a soft or semi-indurated state, we may conclude, that at that time, the solutions from which the veins were filled up, were no longer mixed with those from which the mountains were formed, and consequently, that a vein is of posterior formation to a bed.