make the depth of the Sea, below its Superficies, to be no more perpendicularly measured then the height of the Mountains above it:  ’Tis enough for me to say, there is no one of those that have asserted it, have experimentally known the perpendicular of either; nor shall I here determine, whether there may not be many other causes of the separation of the fresh water from the salt, as perhaps some parts of the Earth through which it is to pass, may contain a Salt, that mixing and uniting with the Sea-salt, may precipitate it; much after the same manner as the Alkalizate and Acid Salts mix and precipitate each other in the preparation of Tartarum Vitriolatum. I know not also whether the exceeding cold (that must necessarily be) at the bottom of the Water, may not help towards this separation, for we find, that warm Water is able to dissolve and contain more Salt, then the same cold; insomuch that Brines strongly impregnated by heat, if let cool, do suffer much of their Salt to subside and crystallize about the bottom and sides.  I know not also whether the exceeding pressure of the parts of the Water one against another, may not keep the Salt from descending to the very bottom, as finding little or no room to insert it self between those parts, protruded so violently together, or else squeeze it upwads into the superiour parts of the Sea, where it may more easily obtain room for it self, amongst the parts of the Water, by reason that there is more heat and less pressure.  To this Opinion I was somewhat the more induced by the relations I have met with in Geographical Writers, of drawing fresh Water from the bottom of the Sea, which is salt above.  I cannot now stand to examine, whether this natural perpetual motion may not artificially be imitated:  Nor can I stand to answer the Objections which may be made against this my Supposition:  As, First, How it comes to pass, that there are sometimes salt Springs much higher then the Superficies of the Water?  And, Secondly, Why Springs do not run faster and slower, according to the varying height made of the Cylinder of Sea-water, by the ebbing and flowing of the Sea?

As to the First, In short, I say, the fresh Water may receive again a saline Tincture near the Superficies of the Earth, by passing through some salt Mines, or else many of the saline parts of the Sea may be kept back, though not all.

And as to the Second, The same Spring may be fed and supplyed by divers Caverns, coming from very far distant parts of the Sea, so as that it may in one place be high, in another low water; and so by that means the Spring may be equally supply’d at all times.  Or else the Cavern may be so straight and narrow, that the water not having so ready and free passage through it, cannot upon so short and quick mutations of pressure, be able to produce any sensible effect at such a distance.  Besides that, to confirm