This argument, of the manganese being in a mine of iron, if I understand it rightly, amounts to this, that, as iron ore is not suspected of having been melted, therefore, we should doubt the manganese having been so.  If this be our author’s meaning, it is not the fair conclusion which the case admits of; for, so far as the manganese appears evidently to have been in a melted state, the iron ore should be suspected of having been also in fusion, were there no other evidence of that fact.  In science, however, it is not suspicion that should be employed in physical investigation; the question at present is; If the phenomena of the case correspond to the conclusion which the intelligent mineralist, who examined them, has formed? and, to this question, our author gives no direct answer.  He says, iron is often found in that form without any suspicion of fusion.  This is what I am now to answer.

The form in which the manganese appears is one of the strongest proofs of those masses having been in fusion; and, if iron should ever be found in that form, it must give the same proof of mineral fusion as this example of manganese; let us then see the nature of this evidence.  The form of the manganese is that of a fluid body collecting itself into a spherical figure by the cohesion or attraction of its particles, so far as may be admitted by other circumstances; but, being here refilled by the solid part on which it rests, this spherical body is flattened by the gravitation of its substance.  Now here is a regular form, which demonstrates the masses to have been in the state of fusion; for, there is no other way in which that form of those reguline masses could have been induced.

There now remains to be considered what our author has observed respecting the intensity of the fire and size of the masses.  “A fire capable of melting quartz might surely produce it (meaning the manganese) in larger masses.”  M. de la Peyrouse says, that those masses were in all respects as if formed by art, only much larger, as the powers of nature exceed those of our laboratories.  What then is it that is here meant to be disputed?  We are comparing the operation of nature and that of art, and these are to be judged of by the product which we examine; but the quantity, in this case, or the size of the masses, makes no part of the evidence, and therefore is here most improperly mentioned by our author.  With regard again to the nature of the fire by which the fusion had been produced, he is much mistaken if he imagines that the reduction of the reguline or metallic manganese depends upon the intensity of the heat; it depends upon circumstances proper for the separation of the oxygenating principle from the calx, in like manner as the calcination of calcareous spar must depend upon circumstances proper for allowing the separation of the carbonic acid or fixed air.