"It being then supposed, that there is but one Element; it is most certain, that all Bodies, according to their several qualities, incline equally towards the Center of the Earth. But you'll ask me, Why then does Iron, Metal, Earth and Wood, descend more swiftly to the Center than a Sponge, if it be not that it is full of Air which naturally tends upwards? That is not at all the Reason, and thus I make it out: Though a Rock fall with greater Rapidity than a Feather, both of them have the same inclination for the Journey; but a Cannon Bullet, for instance, were the Earth pierced through, would precipitate with greater haste to the Center thereof than a Bladder full of Wind; and the reason is, because that mass of Metal is a great deal of Earth contracted into a little space, and that Wind a very little Earth in a large space: For all the parts of Matter, being so closely joined together in the Iron, encrease their force by their Union; because being thus compacted, they are many that Fight against a few, seeing a parcel of Air equal to the Bullet in Bigness is not equal in Quantity. "Not to insist on a long Deduction of Arguments to prove this, tell me in good earnest, How a Pike, a Sword or a Dagger wounds us? If it be not because the Steel, being a matter wherein the parts are more continuous and more closely knit together than your Flesh is, whose Pores and Softness shew that it contains but very little Matter within a great extent of Place; and that the point of the Steel that pricks us, being almost an innumerable number of Particles of matter against a very little Flesh, it forces it to yield to the stronger, in the same manner as a Squadron in close order will easily break through a more open Battalion; for why does a Bit of red hot Iron burn more than a Log of Wood all on Fire? Unless it be, that in the Iron there is more Fire in a small space, seeing it adheres to all the parts of the Metal, than in the Wood which being very Spongy by consequence contains a great deal of _Vacuity_; and that _Vacuity_, being but a Privation of Being, cannot receive the form of Fire. But, you'll object, you suppose a _Vacuum_, as if you had proved it, and that's begging of the question: Well then I'll prove it, and though that difficulty be the Sister of the _Gordian knot_, yet my Arms are strong enough to become its _Alexander_.