This grand mineral view of so large a tract of country is the more interesting, in that there has not occurred the least appearance of volcanic matter, nor basaltic rock, in all that space, where so great manifestation is made of those internal operations of the globe by which strata had been consolidated in their substance, and erected into positions the most distant from that in which they had been formed.
It is peculiarly satisfactory to me, and I hope also to my readers, to have the observations of so able a philosopher and so diligent a naturalist to offer in confirmation of a theory which had been formed from appearances of the same kind in a country so far distant from those of our author now described, as are the Alps of Savoy from those of Scotland. It gives me a singular pleasure, in thus collecting facts for the support of my opinion, to contribute all I can to recommend the study of a work in natural history the most exemplary of its kind; and a work which will remain the unalterable conveyance of precious information when theories making a temporary figure may be changed.
To a person who understands the present theory, there can be no occasion here to give the particular applications which will naturally occur in reading those various descriptions. In these examples are contained every species of bending, twisting, and displacement of the strata, from the horizontal state in which they had been originally formed to the vertical, or even to their being doubled back; and although M. de Saussure had endeavoured to reason himself into a belief of those inverted strata having been formed in their present place, it is evident that he had only founded this opinion upon a principle which, however just, may here perhaps be found misplaced; it is that of not endeavouring to explain appearances from any supposition of which we have not full conviction. I flatter myself, that when he shall have considered the arguments which have here been employed for the manifold, the general operations of subterranean fire, as well as for the long continued operations of water on the surface of the erected land, he will not seek after any other explanation than that which had naturally occurred to himself upon the occasion, and which he most ingenuously declares to have great weight, although not sufficient to persuade him of its truth.
CHAP. II.
The same Subject continued, with examples
from different Countries.
Our theory, it must be remembered, has for principle, that all the alpine as well as horizontal strata had their origin at the bottom of the sea, from the deposits of sand, gravel, calcareous and other bodies, the materials of the land which was then going into ruin; it must also be observed, that all those strata of various materials, although originally uniform in their structure and appearance as a collection of stratified materials, have acquired appearances which often are difficult to reconcile with that of their original, and is only to be understood by an examination of a series in those objects, or that gradation which is sometimes to be perceived from the one extreme state to the other, that is from their natural to their most changed state. M. de Saussure who will not be suspected of having any such theory in his view, will be found giving the most exemplary confirmation to that system of things.
I would therefore beg leave farther to transcribe what he has observed most interesting with regard to that gradation of changed strata. It is in the high passage of the Bon-Homme, tom. 2. p. 179.
«Depuis le col, dont je viens de parler, jusqu'a la croix, qui suivant l'usage, est placée au point le plus élevé du passage, on a trois quarts de lieue, ou une petite heure de route, dans laquelle on traverse des grès, des brèches calcaires, des pierres calcaires simples de couleur grise, d'autres calcaires bleuâtres et des ardoises: ces alternatives se répètent à plusieurs reprises. Parmi ces grès on en trouve qui renferment des cailloux roulés, et qui font effervescence avec les acides; d'autres qui ne renferment point de cailloux, et qui ne font point d'effervescence.
«Quelques-uns de ces grès m'out paru remarquables par leur ressemblance avec des roches feuilletées; ils sont compactes mêlés de mica; un suc quartzeux remplit tous les interstices de leurs grains, et leur donne une dureté et une solidité singuliers; il n'y a personne, qui en voyant des morceaux détachés de cette pierre, ne la prît pour une roche feuilletée; mais quand on la trouve dans le lieu de sa formation, et qu'on voit les gradations qui la lient avec des grès indubitables, par exemple avec ceux qui renferment des cailloux roulés, on ne peut plus douter de sa nature. Ces couches sont en général inclinées de 30 degrés en descendant au sud-est.»
Our author would here make a distinction of the roche feuilletée and the grès; the one he considers as primitive, and as having had an origin of which we are extremely ignorant; the other he considers as a secondary thing, and as having been formed of sand deposited at the bottom of moving water, and afterwards becoming stone. This great resemblance, therefore, of those two things so different in the opinion of naturalists, struck him in that forcible manner. Nothing can be a stronger confirmation of the present theory, which gives a similar origin to those two different things, than is the observation of so good a naturalist, finding those two things in a manner undistinguishable.