[Note 42:  Here we have well informed naturalists reasoning with all the light of our present mineralogy, and maintaining, on the one hand, that gypsum is transformed into calcedony, by the operation of the meteors, or some such cause; and, on the other, that a siliceous substance is by the same means converted into lime-stone.  What should we now conclude from this?—­That calcareous and siliceous substances were mutually convertible.  But then this is only in certain districts of Poland and Siberia.  Every where, indeed, we find strange mixtures of calcareous and siliceous bodies; but neither mineralists nor chemists have, from these examples, ventured to affirm a metamorphosis, which might have spared them much difficulty in explaining those appearances.

This is a subject that may be taken in very different lights.  In one view, no doubt, there would appear to be absurdity in the doctrine of metamorphosis, as there is now a days acknowledged to be in that of lusus naturae; and those reasoning mineralists might thus, in the opinion of some philosophers, expose their theory to contempt and ridicule.  This is not the light in which I view the subject.  I give those gentlemen credit for diligently observing nature; and I applaud them for having the merit to reason for themselves, which would seem to be the case with few of the many naturalists who now speak and write upon the subject.

Let us now draw an inference, with regard to this, in judging of the different theories.  Either the received system concerning mineral operations is just, in which case those gentlemen, who employ a secret metamorphosis, may be to blame in laying it aside; or it is erroneous and deficient; and, in that case, they have the merit of distinguishing the error or deficiency of the prevailing system.  How far they have seen the system of nature, in those examples which they have described, is another question.  In the mean time, I am to avail myself of the testimony of those gentlemen of observation, by which the insufficiency at least of the received mineral system is acknowledged.]

After speculating upon the effect of the ancient ocean upon the mountains of that country, he proceeds as follows: 

“Je laisse ces conjectures pour remarquer un fait singulier:  la colline, qui est au nord de l’eglise de la fonderie, a son arrete composee de ce hornstein qui se decompose en pierre calcaire; mais ici, les parties, qui sont ainsi decomposees, offrent une substance calcedonieuse disposees par zones concentriques, comme on l’observe dans les agates d’oberstein; mais ce ne sont point ici des corps parasites formes par infiltration dans des cavites pre-existantes comme les agates; on voit que ce sont les parties constituantes de la roche qui, par un travail interne, et par une sorte de crystallisation, out pris cette disposition reguliere (que ce mot de crystallisation ne revolte point, j’appelle ainsi toute tendance a prendre une forme constante, polyedre ou non polyedre.) Les couches les plus voisine du centre sont nettes et distinctes; peu-a-peu elles le sont moins, et enfin elles s’evanouissent et se confondent avec le fond de la roche.  Chaque assemblage de ces zones a une forme ronde ou ovale plus ou moins reguliere de sept a huit pouces de diametre.