The system of natural history ... / abridged ; with additional extracts from other writers.

  • Buffon, Georges Louis Leclerc, comte de, 1707-1788
Date:
1791
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Licence: Public Domain Mark

Credit: The system of natural history ... / abridged ; with additional extracts from other writers. Source: Wellcome Collection.

    22/506 (page 6)
    they were originally covered by fuperior ft rata of confiderable depth ; but that they now occupy the higheft ftations, becaufe they were laft tranfported by the waves. To confirm this reafoning, it is worthy of remark, that, the differ- ent ftrata of ftones in quarries are almoft all horizontal or regularly in- clined. Indeed the ftrata of granite, vitrifiable fand, clays, marbles calcareous ftones, chalk, and marles, are always parallel or equally in- clined. And, the difpolkion of ftrata, as deep as mankind have pe- netrated is the fame. Thole beds of land and gravel which are wafhed down from the mountains, muft, in fome degree be excepted from the general rule. And as they are formed by rivers and brooks which often change their channels, it is not furprizing that they are lb frequent. The ftrata formed by rivers are not very ancient; they are ealiiy diftinguifbed by their frequent interruptions, and the inequality in thicknefs, which is conftai^tly varying, but the ancient ftrata uniformly preferve the fame dimeniions throughout. Thefe modern ftrata may likewife be diftin- guifhed by the form of the ftones and gravel they certain, which bear evident marks of having been rounded by the motion of water. The fame oblervation holds good with refpeft to thofe beds of turf, and corrupted vegetables, wdrich are found in marfhy grounds, immediately below the foil; and which have derived their origin from fucceftive accumulations of decayed trees, and other plants. The ftrata of flime and mud being formed by ftagnating waters, or the inundations of rivers, are neither fo perfectly horizontal, nor fo uniformly inclined, as thofe produced by the regular motions of the lea. In ftrata formed by rivers, we meet with river and feldom wflth lea fhells ; but in the ancient ftrata there are no river lliells ; the fea Ihells are numerous, well prel’erved and all placed in the fame manner. From whence could this beautiful regularity proceed ? Inftead of regular ftrata, why do wTe not find the materials which compole the earth huddled together without order ? Why are not rocks, marbles, clays, marles. Scc. fcattered promifeuoufly, or joined by irregular or vertical ftrata ? Why are not heavy bodies found in a lower fituation than light ones ? It is eafy to perceive, that this uni.% rmity of nature, this fpecies of organi- zation, this union of different materials by parallel ftrata, without regard to their weights could only proceed from a caule equally powerful and uniform as the motions of the fea, produced by regular winds, or by the flux and reflux, Scc. As thefe caufes act with fuperior force under the equator than in o- ther climates, the chains of mountains are moll extenlive in its neigh- bourhood. Thus the mountains of Africa and Peru are both the high- eft and moft extenftve in the world. The mountains of Europe and Alia, which extend from Spain to China, are not fo high as thofe of Africa and South America. Belides, in the northern feus, the illands are but few, wrhen compared with thofe in the Torrid Zone. As illands, therefore, are nothing but the fummits of mountains, it is clear that there are more inequalities on the furface of the earth, near the equator tlran in northerly climates. Thofe vaft chains of mountains which run from weft to eaft in the old continent, and from north to fouth in the newq muft have been for- med by the general motion of the tides. But the or 'T of flic l'maller