“Mais ce qui est digne de la plus grande attention dans cette contree, est un filon peu distant nomme Buchenberg, qui appartient en partie au Roi, et en partie a Mr. le Comte de Wernigerode.  La montagne en cette endroit montre une vallee artificielle de 70 a 80 pieds de profondeur, de 20 a 30 de largeur dans le haut, et de 400 toises en etendue.  C’est le creusement qu’on a deja fait en suivant ce filon de fer, que l’on continue a exploiter de la meme maniere sur les terres de Mr. le Comte de Wernigerode.  La matiere propre de la montagne est de schiste; et la vallee qui se forme de nouveau a mesure qu’on enleve la gangue du filon, a surement deja existe dans la mer sous la forme d’une fente, qui a ete remplie, et en particulier des ingrediens dont on fait aujourd’hui le fer.”

Here is a supposition of our author that corresponds to nothing which has yet been observed any where else, so far as I know.  It is concerning a mineral vein, one which does not appear to differ in any respect from other mineral veins, except in being worked in that open manner which has given our author an idea of its being a valley.  He then supposes that valley (or rather empty vein) to have been in this mountain when at the bottom of the sea, and that this mineral vein had then been filled with those materials which now are found in that space between the two sides of the separated rock.  This is a very different operation from that of infiltration, which is commonly supposed to be the method of filling mineral veins; but, we shall soon see the reason why our author has here deserted the common hypothesis, and has adopted another to serve the occasion, without appearing to have considered how perfectly inconsistent those two suppositions are to each other.  That mineral veins have been filled with matter in a fluid state, is acknowledged by every body who has either looked at a mineral vein in the earth, or in a cabinet specimen; mineralists and geologists, in general, suppose this to have been done by means of solutions and concretions, a supposition by no means warranted by appearances, which, on the contrary, in general demonstrate that the materials of those veins had been introduced in the fluid state of fusion.  But here is a new idea with regard to the filling of those veins; and, I would now beg the reader’s attention to the facts which follow in this interesting description, and which have suggested that idea to our author.

“Quand cette matiere accidentelle est enlevee, on voit la coupe du schiste des deux cotes de la fente, faisant un toit et un mur, parce que la fente n’est pas absolument verticale:  des qu’il y a un peu d’inclinaison, on distingue un toit et un mur, comme j’ai l’honneur de l’expliquer a V.M.  On ne connoit point encore l’etendue de ce filon, ni dans sa profondeur, ou l’on ne peut pas s’enfoncer beaucoup de cette maniere, ni dans la longueur, selon laquelle on continue a l’exploiter.