“Le quartz s’y trouve comme dans les pierres de la premiere section, c, a, d, crystallise, en groupes dans de petites cavites; quelquefois aussi en veines.  La calcedoine y est de meme, ou bien en mamelons, ou bien en stalactites, lorsqu’elle a de la place pour s’y deposer.

“Un phenomene encore plus curieux que cela est cette belle pyrite sulphureuse jaune, comme de l’or, qui est quelquefois parsemee par tout la substance de petrifications agathisees, et qui apparemment y fut deposee apres la dite metamorphose a la faveur des petits pores, qui y etoient restes ouverts.”

I would beg that mineralists, who use such language as this, would consider if it contains a distinct idea of the operation which they would thereby describe, or if it does not contain either a contradiction or an inconceivable proposition.  It supposes a calcareous body to be metamorphosed, somehow by means of the mountain acid, into a siliceous body.  But, finding many bodies of pyrites contained within that solid flint, it is said, that, when the calcareous body was flintified, there were left in it cavities which were afterwards filled with pyrites.  Let us reflect a moment upon this doctrine.  These cavities were first open to the outside of the flinty body; but now the pyrites with which they had been filled is insulated in the solid flint.  Here three things are required; first, The calcareous body is to be flintified, at the same time leaving the body full of small cavities open to the outside; secondly, These cavities are to be filled with pyrites; lastly, These mineral bodies are to be so inclosed within the flint, as to leave no vestige of the former processes.  This marly mountain itself, which had been formed of loose materials gathered together at the bottom of the sea, was first to be filled with pyrites, in various shapes, by means of the phlogistic and the acid of the mountain.  Here is proposed to us an operation which is totally unknown, or of which we have no kind of idea.  But, let us suppose pyrites formed in this mountain, (of whatever chemical substances), by means of water; Why should water again undo that pyrites, in order to form other concretions?  And, Why should the flint be formed first with cavities, and then made solid, after pyrites had been introduced into those cavities of the agate, and, as our author expresses it, parsemee pour toute la substance? Here are suppositions which are not only perfectly gratuitous, but are also inconsistent with any thing that we understand.  This is not explaining nature; it is only feigning causes[39].

[Note 39:  The description of those insulated siliceous bodies, containing in their closed cavities all the usual concretions of calcedony and crystals, as well as full of small pyrites floating in the solid flint, are extremely interesting to a mineral system, or such a geological theory as should explain the present state of things in those strata that had been formed by deposits of known materials at the bottom