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was of Opinion that the Body of the Earth within is nothing but a very hard Loadstone; and that thefe exteriour Parts towards the Surface, which are penetrated into by digging, and on which Herbs grow and we live, are but as it were the Bark and Cruft of the Earth, and the Seat of perpetual Generation and Corruption. The Opinion of des Cartes is not much different from this; for he believed there were three Strata in the Body of the Earth of divers Confiftences. The first and innermoft poffeffing the Center, the second of a denfe and opaque Nature, confifting of the minuteft Particles; the third (being replete with Men and Animals) he fuppofes to be compounded of Particles not sticking fo close together.

NEVERTHELESS, for want of Obfervation, we cannot affirm any Thing for Certainty in this Matter; and tho' it be true that in several fubterraneous Places, there is a glowing Heat, and that Smoke and fulphureous Fumes are exhaled from feveral hot Baths: and alfo tho' Thurnbeufer affirms, that he found by Experience that the nearer they digged to the Center of the Earth, there was the lefs Water in Mines; yet we are ftill in a Doubt, and cannot pofitively depend upon his particular Obfervation.

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PROPOSITION VI.

The Confiftence or Coberence of the Particles of the Earth is from Salt.

THE artificial Separation of the Particles of Bodies demonstrate, that in the Compofition of the whole there is a certain kind of Salt which is more abundant in harder Bodies, as in Metals, Stones, &c. (a few oily Subftances only excepted) (e). And that all folid Bodies are concreted by Salt, is manifest from the artificial Petrefaction of those that are soft, to any Degree of Hardness by it.

(e) Tho' moft forts of Bodies are replete with faline and vitriolic Particles, fuch as may, in fome Means contribute to their Coagulation and Confolidation; yet the primary and naturally indivisible Corpufcles, of which the Particles of all Bodies are compofed, are not connected by falt or hooked Atoms, as fome imagine; nor glewed together by Reft, which is an occult Quality or nothing, nor ftick together by confpiring Motions, but rather cohere and are united by mutual Attraction. So that the malleft Particles of Matter may cobere by the Strongeft Attractions, and compofe bigger Particles of weaker Virtue; and many of these may cobere, and compofe bigger Particles whofe Virtue is still weaker. See Newton's Optics, Pag.

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Attraction of their Parts, com pofe a Body very hard; and if thefe Particles are not fo ftrongly attracted or entangled with each other, the Body will be brittle; if they touch one another in lefs Superficies, the Body is not fo hard, but yet may be more folid; if they only approach each other, without flipping one under another, the Body is Elaftic, and springs to it's former Figure; if they flip under each other the Body is soft, and eafily yields to the Stroke of the Hammer; if they fcarce touch one another the Body is crumbling, or fuch whose Parts may be easily separated; if they are fmall, round, flippery, and eafily agitated by Heat, the Body is fluid; if thefe Particles are of an unequal Superficies, and hooked or entangled one with another, then is the Body flexile or pliant, &c. See Dr Clarke's Notes upen Robault's Phyfics.

So

So that if Salt be feparated from Bodies, their Particles will no longer be cemented; but they will become Powder, which cannot be brought to a Coherence without the Admixtion of faline Particles.

PROPOSITION VII.

Various kinds of Bodies are feveral Ways mixed together in the Globe of the Earth.

IN Mines there are found Particles of Gold, Silver, Lead, &c. not gathered into a Mafs and separate from others; but fometimes mixed among themselves, and fometimes with ufelefs Earth, in fuch very fmall Particles that the beft Judges in Metals cannot at firft Sight difcover what fort of Mineral is contained in fome Metalline Earths (f). Alfo in the Fields, Sand is fometimes

(f) The indefatigable Dr Woodward, in his Effay towards a Natural History of the Earth, reafonably fuppofes all these Commixtures of the Particles of Bodies in the Strata of the Earth, to proceed from thofe ftrange Alterations that were every where made in the Terreftrial Globe at the Deluge, when the whole Globe was diffolved, and the Particles of Stone, Marble, and all other folid Foffils diffevered, taken up into the Water, and there fuftained together with Sea Shells, and other animal and vegetable Bodies: that at length all these fubfided from the Water, according to the Nature of their Gravity; the heaviest Bodies firft, then those that were VOL. I.

lighter; but all that had the fame Degree of Gravity fettled down at the fame Time; fo that thofe Shells, or other Bodies, that were of the fame fpecific Gravity with Clay, Chalk, Sand, &c. funk down together with them, and fo were inclofed in the Strata of Chalk, Clay, Sand, or Stone, which their Particles formed; that at the general Subfidence, Metals and Minerals, as well those which were amaffed into Lumps as thofe which continued afunder, and in fingle Corpufcles, funk down to the Bottom along with Sand, Coal, Marble, &c. and fo were lodged with the Strata which the Sand, &c. conftituted. That all the metallic and mineral Matter which H

is

fometimes mixed with Clay or Lime, and fometimes with Salt, &c. Not long fince at Amfterdam, when the Earth was digged up to the Depth of two hundred thirty two Feet to make a Well, thefe kinds of Earth were gradually discovered. First seven Foot of Garden Mould, then nine Foot of black combuftible Earth, which is called Peat, (not like that they properly call Dutch Turf) then nine Foot of foft Clay, then eight Foot of Sand and four of common Earth, then ten Foot of Clay, and again four of common Earth, next that ten Foot of fuch Sand as the Foundations of the Houfes in Amfterdam are laid in, then two Foot of Clay, next four Foot of white Gravel, then five Foot of dry Earth, and one Foot of Mud, again fourteen Foot of Sand, then three Foot of fandy Clay or Mire, afterwards five Foot of Sand mixed with Clay, and next four Foot of Sand mixed with little Sea-Shells, then there was a Stratum of Clay one hundred and two Foot deep, and laftly thirty one Foot of Gravel, where the Shaft was finished,

is now found in the Fiffures, or perpendicular Intervals of the Strata, was originally lodged in fingle Particles among the Sand, &c. having been detached and drawn thence by little and little by the Water, which continually pervades the Strata; and that Trees, which are found in great Plenty in Moffes, Fens, or Bogs,were depofited thereby the Deluge; fo that the prefent Earth was formed out of this promifcuous mixed Mafs of Sand, Earth, Shells, and Metals, and of broken and disloca

ted Strata, some elevated and others depreffed, by which Means all the Inequalities of the Globe, Fiffures, Grotto's, Mountains, Vallies, Islands, the Chanel of the Sea, and all others, were formed, and that the whole Terraqueous Globe (with all it's Materials) was, at the Time of the Deluge, put nearly into the Condition that we at this Day behold it. See Woodward's Efay, or Philofophical Tranfactions No 217. p. 115.

PRO

PROPOSITION VIII.

The Cavities of the Earth, and the external and internal Difpofition, or Situation of it's Parts, are not perpetually the fame, but different at different Times.

THE Sea not only makes many Devaftations and Changes in the Parts of the Earth, by fome of it's Paffages being stopped, and others more opened; but also that fpirituous and fulphureous. Substance which here and there lies hid in the interior Parts, when it begins to heat and evaporate, impetuously shakes the exterior Parts of the Earth, raising them up, as is ufual in Earthquakes. And it is probable the like Eructations may often happen in the more interior Parts of the Earth; which for the most part we have no Notion of. W E fhall treat of the mutual Changes of Land and Water in Chapter 18. hereafter.

The Terraqueous Globe is divided into

Earth whofe S covered with Water, or raised aSurface is bove the Waters; and into Water.

THE Superficies of that Part of the Earth which appeareth above the Waters, is, by the Interflux of the Sea thus divided.

I. INTO large Continents, or great Islands, which we fuppofe to be four.

H 2

North

by

the Hyperbo

rean Frozen

and Tartaric Ocean.

1. The

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