Mr. _Boyle_ found that a _solid body_, as _ponderous_ as any yet known, though near the top of the water it would sink by _its own weight_, yet if it be placed at a greater depth than twenty times its own thickness, it will _not sink_, if its descent be not assisted by the _weight_ of the _incumbent water_. To prove this, he gives us a curious experiment, viz. by keeping off the _pressure_ of the water, from the _top_ of the _sinking body_, and _sinking_ it to a proper depth, he found, that the _most ponderous_ body would be _buoyed up_, and _supported_ by the water only. See the 2d vol. of _Boulton_’s epitome, pag. 305. This experiment shews us beyond all contradiction, that the _earth_ has no power of _attraction_, nor a _descending body_ any power of _gravitation_; for if it had, the farther it was sunk in the water, the nearer it must be to the centre of the earth, and of consequence the _attraction_ must be the greater; but this, we find, is contrary to experience; so that the whole power of descending is impressed upon it by the _air_, or by other bodies forced upon it by the _incumbent air_. This experiment alone is more than sufficient to destroy the fine theories of _attraction_ and _gravitation_; it also shews us how, and by what means, two marble slabs, finely polished, are what they call _attracted_ to each other, and require a great force to separate them; a force in proportion to the breadth of the slabs; but this has been shewn by other experiments to be nothing but the _pressure_ of the _air_, or _atmosphere_; for put them into an air pump, and extract the _gross air_, and they will immediately separate from each other.