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1. It is an agreeable prospect to see, from such a table as this, how finite and comprehensible the nature of tangible bodies is; for such a table grasps, as it were, all natural bodies in the hand. And let no man here indulge his fancy, or his levity; but consult experience: for our table shews, that there is no tangible body in nature exceeding another in quantity of matter, above thirty-two to one; which is the proportion wherein gold exceeds fir-wood. As for bodies near the centre of the earth, we can say nothing to them; since they neither come under our senses nor experience: possibly, as they lie very remote from the heat of the celestial bodies, and are quite cut off from any communication therewith; they may be more dense than any of the bodies we know.

2. There can be little justness in that opinion, which supposes sublunary bodies composed of the four elements. For our cubical lump of gold in the table, was twenty penny-weight; whereas common earth is little more than two; water but one and three grains; and air and fire are still vastly more rarified, as being not

required. See Mr. Boyle's piece of Hydrostatics applied to Ores and the Materia Medica; and for the uses of such a table, see hereafter.

tangible, and insensible upon the balance: and form does not increase the matter of bodies.. It must, therefore, on this footing, be considered, which way a body of twenty penny-weight, can by form be produced, under equal dimensions, from a body of two penny-weight; and from others vastly more rarified. There are here two subterfuges; the one, that the more rarified elements squeeze the denser to a greater closeness than the simple element itself: the other, that the peripatetics do not understand this of common, but of elementary earth; which is heavier than any compound substance. But fire and air do not condense bodies, except by accident; as we shall shew hereafter. And for the earth, which should be heavier than gold, and all other bodies; it is so buried, as hardly to be found, and employed in mixture.* It were, therefore, much better for the Peripatetics to leave off trifling, and dictating in philosophy.

3. The scale of density in bodies, or the degrees wherein they fall from a closer texture of matter, to a looser, should be carefully noted; and how this sometimes happens by smaller steps, and sometimes by larger strides such a view being of service, not only to inform the. judgment, but also in leading to practice. The


* See Mr. Boyle's Sceptical Chemist.

density of metalline bodies is the greatest; and runs eleven steps downwards, from gold to tin; proceeding by a large start from gold and quicksilver, to lead; but gradually, or slowly, from lead to tin. Again; there is a great leap from metals to stones; only the loadstone comes in between; which is thence proved to be of metallic nature.* But from stones to all other bodies, there is a continued, regular, and slow des




1. As the seat of density may seem to be in the depth of the earth; so the bodies towards its surface should be considerably rarified but it is very remarkable, that gold, the heaviest of metals, should sometimes be found, nearly in a pure state, among the sand and gravel of rivers. A careful enquiry should be made into the situation of such places; to discover whether they lie not near the foot, or below the bottom of certain mountains, or deep mines, from whence the gold may be washed: or otherwise, what it is that procures so great a degree of density, near the surface of the earth.

* Such particulars as these are frequently taken for late discoveries.

The former is generally allowed to be the case; viz. that gold is washed down into rivers, from mines that lie

2. It should also be enquired, as to mines in general, what kind of them lie the deepest, and what nearest the surface of the earth; in what situation of a country, and in what kind of glebe or soil; how they lie with respect to the waters; but particularly in what beds; and how they are surrounded, or mixed in with stone, or other fossil matters. In short, all the circumstances belonging to them should be examined; in order to find out by what means the juices and spirits of the earth are compacted, and condensed into a metalline nature, so much heavier than that of other bodies.*


1. No doubt but there are many bodies to be found, both in vegetables and the parts of animals, much lighter than fir-wood; for, we conceive that the downs of some plants, the wings of flies, the skins of snakes, and various matters treated or produced by art; such as tinder, dry rose-leaves remaining after distillation, &c. are not so heavy as the lightest woods.†

higher yet the question still remains, whence has gold its density; being often found in mines not far below the earth's surface?

*See the heads of this enquiry in the Philosophical Transactions; or in Mr. Boyle's works, Abridg. vol. viii. + See Dr. Hook's Micrographia passim.

2. That erroneous notion, to which the human understanding readily inclines, in supposing hard bodies the densest, should be corrected and restrained for quicksilver runs, and gold and lead are soft; yet these are denser and heavier than the hardest metals, iron and copper; and much denser than stones.

3. Our table of specific gravities, shews many things contrary to expectation; as that metals are much heavier than stones; glass, a factitious body, heavier than chrystal; that common earth is considerably light; that the oils, or distilled liquors of vitriol and sulphur, are almost as heavy as crude vitriol or sulphur; that the difference between the gravity of water and wine is not great; that some chemical oils, which should seem lighter, are yet heavier than oils by expression; that bone is much heavier than horn or teeth: with several particulars to the same effect.


The nature of density and rarity, though it runs through nearly all other natures, without being subject to their laws; yet seems to have a great consent with gravity and levity.* We also suspect it may have an agreement with the slow and quick admission, and rejection, of heat

* It is now generally esteemed reciprocal thereto.

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