no more
solidity to the hardest body in the world than to the softest; nor is an
adamant one jot more solid than water. For, though the two flat sides of
two pieces of marble will more easily approach each other, between which
there is nothing but water or air, than if there be a diamond between
them; yet it is not that the parts of the diamond are more solid than
those of water, or resist more; but because the parts of water, being
more easily separable from each other, they will, by a side motion, be
more easily removed, and give way to the approach of the two pieces of
marble. But if they could be kept from making place by that side motion,
they would eternally hinder the approach of these two pieces of marble,
as much as the diamond; and it would be as impossible by any force to
surmount their resistance, as to surmount the resistance of the parts of
a diamond. The softest body in the world will as invincibly resist the
coming together of any other two bodies, if it be not put out of the
way, but remain between them, as the hardest that can be found or
imagined. He that shall fill a yielding soft body well with air or
water, will quickly find its resistance. And he that thinks that nothing
but bodies that are hard can keep his hands from approaching one
another, may be pleased to make a trial, with the air inclosed in a
football. The experiment, I have been told, was made at Florence, with
a hollow globe of gold filled with water, and exactly closed; which
further shows the solidity of so soft a body as water. For the golden
globe thus filled, being put into a press, which was driven by the
extreme force of screws, the water made itself way through the pores of
that very close metal, and finding no room for a nearer approach of its
particles within, got to the outside, where it rose like a dew, and so
fell in drops, before the sides of the globe could be made to yield to
the violent compression of the engine that squeezed it.

5. On Solidity depend Impulse, Resistance and Protrusion.

By this idea of solidity is the extension of body distinguished from
the extension of space:--the extension of body being nothing but the
cohesion or continuity of solid, separable, movable parts; and the
extension of space, the continuity of unsolid, inseparable, and
immovable parts. Upon the solidity of bodies also depend their mutual
impulse, resistance, and protrusion. Of pure space then, and solidity,
there are several (amongst