eat? And do not hot Bodies
communicate their Heat to contiguous cold ones, by the Vibrations of
this Medium propagated from them into the cold ones? And is not this
Medium exceedingly more rare and subtile than the Air, and exceedingly
more elastick and active? And doth it not readily pervade all Bodies?
And is it not (by its elastick force) expanded through all the Heavens?

_Qu._ 19. Doth not the Refraction of Light proceed from the different
density of this AEthereal Medium in different places, the Light receding
always from the denser parts of the Medium? And is not the density
thereof greater in free and open Spaces void of Air and other grosser
Bodies, than within the Pores of Water, Glass, Crystal, Gems, and other
compact Bodies? For when Light passes through Glass or Crystal, and
falling very obliquely upon the farther Surface thereof is totally
reflected, the total Reflexion ought to proceed rather from the density
and vigour of the Medium without and beyond the Glass, than from the
rarity and weakness thereof.

_Qu._ 20. Doth not this AEthereal Medium in passing out of Water, Glass,
Crystal, and other compact and dense Bodies into empty Spaces, grow
denser and denser by degrees, and by that means refract the Rays of
Light not in a point, but by bending them gradually in curve Lines? And
doth not the gradual condensation of this Medium extend to some distance
from the Bodies, and thereby cause the Inflexions of the Rays of Light,
which pass by the edges of dense Bodies, at some distance from the
Bodies?

_Qu._ 21. Is not this Medium much rarer within the dense Bodies of the
Sun, Stars, Planets and Comets, than in the empty celestial Spaces
between them? And in passing from them to great distances, doth it not
grow denser and denser perpetually, and thereby cause the gravity of
those great Bodies towards one another, and of their parts towards the
Bodies; every Body endeavouring to go from the denser parts of the
Medium towards the rarer? For if this Medium be rarer within the Sun's
Body than at its Surface, and rarer there than at the hundredth part of
an Inch from its Body, and rarer there than at the fiftieth part of an
Inch from its Body, and rarer there than at the Orb of _Saturn_; I see
no reason why the Increase of density should stop any where, and not
rather be continued through all distances from the Sun to _Saturn_, and
beyond. And though this Increase of density may at great distances be
exceeding