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by the superincunibent Water, it is forced to give way, and finding no place to fiow to, it retires towards the sides, and pervades the Foundations of the Mountai.is ; where being collected, as in a Cistern, it is still urged forwards towards the tops of the Mountains by the incumbent Water of the Ocean. As we may observe in a Tankard that has a Pipe on the side {reaching to the very bottom) made to pour Wine thro' into Glafíes; if, I say, we drop a Stone into such a Vessel, whether it be full or half full of Liqnors it will spout out at the Orifice of the Pipe. This is Scaliger's Subtility, but it is too gross to pass. For the Water is not thus forced towards the tops of the Mountains, since Experience shews us the contrary in Mines, and if it were so, the Water of all Springs would be falt; besides, it is false to say that the Water is not in it's natural Place, and therefore presses upon the Water underneath, for this is allumed without Proof, and is contrary to Experience. Water does not press upon the Parts below, unless it's Surface be of an unequal Altitude, but the Surface of the Ocean is spherical and consequently at Rest. Moreover, if the Waters were moved by any Pressure, it would be towards the Shores, where the Passage is more open than the small Fissures of the Earth. And tho' there be great outlets at the bottom of the Sea, for the Water to flow through, yet since it is salt, it cannot make fresh-water Fountains. I think the true Answer to this Argument is not far to fetch, if, we consider how Water is conveyed to Fountains, not by any Chanel or Pipe from the bottom of thc Sea, or the Root of the Mountain (by which means it would still keep it's Saltness), but by a continual distilling, gleeting, and straining of the watery Particles thro' the terrestrial Matter, till they find a Receptacle fit to collect and condense them into Drops, where being continually succeeded by

others,

others, they have recourse to some Conveyance, and through it break forth at a Fountain. And we observe this very thing in Mines dug to a vast Depth, how that Water on every Side is continually dropping, and collecting itself into small Guts, which they call Veins of Water; and if several such Guts or Runnels as these concur in one Receptacle, they form a Fountain, as they who make Drains, to bring Water into Wells, very well know. For in most Draw-Wells the Water is collected from the dropping of the Earth, round about into the bottom of the Well ; and they that make Aqueducts dig small Furrows in Gutters to collect the Waters, and then convey it in a large one to the intended Place. If it be objected, that many Fountains are observed to spring up among Rocks, where it is likely the watery Particles can scarce be admitted ; I answer, That this confirms our Opinion ; for these Rocks are not continued to the foot of the Mountain (upon which such Springs are found) but only cover the Surface to a small Depth, and the Earth is lighter and less rocky within, or at least fit to give Admission to the Water, which, when it comes to the Strata of the Stones, can penerate no farther, but is there impeded and collected into Drops, and breaks out into a Fountain among the Rocks, if it can find any Aperture. Moreover, the rocky Mountains in the Inand of $1 Helena, and in most other Inands, are not within so dense and obdurate, as appears from the Cinders, Ashes, and sulphureous Earth; which shews that these Mountains some time or other burnt or smoaked. And to this we may add, that the Fountain is not always in the place where the Water breaks out, which is conveyed very often from a higher Place, by a Chanel under Ground, and this causes it to break forth with greater Violence, as is very often observed,

X. 4.

We We may be further convinced of the Truth of these Things, by considering that Fire will tend downwards thro' a Continuation of Matter, tho? of it's own Nature, when it is free from Matter, it tends upwards, Thus if you put one End of a Bar of Iron into the Fire, it will penetrate thro' the whole, and heat the other End, tho' it be turned downwards. And this is sufficient to convince any one of the Invalidity of the first Argumeni.

TO the Second we answer, That the Reason why the Sea-Water doth not penetrate and fink into the Earth towards the Center, so much as into the Mountains, is, because the Earth there is denser, and full of Metals, as we find by Experience; but where it is not so obdurate, the Water glides in, and therefore if there are Receptacles under the bottom of the Sea, we do not deny but that there may be some fresh and salt Water Lakes there. But because there are few fuch Receptacles, and the Earth every where is denfe and metalline, under the bottom of the Sea, it cannot constantly imbibe Water ; but when it is faturated it receives no more, and then the overplus Water dittils towards the higher Places. And the Sea constantly changing it's Altitude, and fluctuating backwards and forwards, may contribute much to elevate the Water ; for where it is higher than ordinary, it must certainly press the Water into the Earth, and drive it to the Fountain-Heads, And since the Surface of the Ocean in every Place is constantly agitated, and made higher and lower, not only by Storms, but also by the Tides, therefore such a Pressure as this must happen every Day. But I question whether this can do much.

TO the third Argument we say, That this is owing to the Disposition or Situation of the Strala of the Earth, or of the Earth it felf, and that it is

the the nature of all Fluids to gather to a Head, where there is a Flux. I think there is no need of laying any more to this. · BUT the fourth is not so easily answered, for we do not perceive Salt to be separated from SeaWater only by Percolation or Straining. Beside, there are two kinds of Salt in Water (which the

Aristotelians did not consider) the one of which is very well named, by Chymists, fixed, and the other volatile. The fixed' Salts may indeed, by continual straining, or boiling, or distilling of the Sea-Water, be separated from it; but the volatile Salt is so full of Spirit, that it flies up with the Water, and cannot be separated from it, neither by frequent Distillations nor any other Art hitherto used. Therefore it is very difficult to shew how this volatile Spirit of Salt is separated from the SeaWater, in it's Passage from the Ocean to FountainHeads. The following Accounts will serve our Turn. 1. Tho'we have not found out the Art of separating the volatile Spirit of Salt from Sea-Water, yet we cannot deny but that it may be done, since we fee it separated by Nature, when it rains fresh Showers in the main Ocean, tho' they proceed from Vapours exhaled from the Sea. '2. The Particles of falt Water which pervade the Fissures of the Earth, before they come to their Fountain, are mixed with other fresh Water, which proceeds from Rain and Vapours condensed there, whereby the small Degree of volatile Salt that remains in them is rendered insensible. 3. It is not true that all Fountains are entirely deprived of Saltness, for there are some salt Springs, as we said before, a. bout two Miles from Suez, and in several other Places not so far from the Sea. Therefore to feparate the volatile Salt from the Water, a long Transcolation, and a gentle Evaporation is requirçd, and thus it is to be separated by Art ; and

thus

thus also is Rain-Water generated and made fresh; tho’ sometimes faltish Showers are observed to fall into the Sea.

THE Water of Springs therefore proceeds partly from the Sea, or subterraneous Water, and partly from Rain and Dew that moistens the Earth. But the Water of Rivers proceeds partly from Springs, and partly from Rain and Snow.

PROPOSITION VI.

Some Rivers in the middle of their Course, hide them

selves under Ground, and rise up in another Place, as if they were new Rivers,

THE most famous are: : 1. THE Niger, a River in Africa, which some antient Cosmographers would have to proceed from the Nile, by a subterraneous Chanel, because it overflows it's Banks at the same Time of the Year, and after the same manner that the Nile does : and they could not shew a better Cause for it's Inundation. This River meeting with the Mountains of Nubia, hideth itself under them, and emerges again on the West Side of the Mountains (c).

2. THE Tigris in Mesopotamia, after it has passed the Lake Arethusa, meets with Mount Taurus, and plunges itself into a Grotto, and flows out at the other Side of the Mountain ; also after

(c) This River hides itself no taken for the upper part of the where under Ground that we Nile) meeting with the Mounknow of; tho' perhaps we are tains of Nimeamay, is said to not certain whether it do or no, divide itself into several streams, because no European has traced and immerge under them, and it to it's Fountain : Only the to emerge again on the North Zeebe, a large Branch of it, side of the Mountains. But I do (which proceeds from the Lake not write this as a Certainty. Zaire, and was some time since

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