th, or
vanish into _Air_, but is _driven_ (by that Fluid equally protruding it on
every side) and forc't into as little a space as it can possibly be
contained in, namely, into a _Round Globule_. So likewise a little _Air_
blown under the _water_, is _united_ or thrust into a _Bubble_ by the
ambient water. And a parcel of _Quick-silver_ enclosed with _Air_, _Water_,
or almost any other _Liquor_, is _formed_ into a _round Ball_.

Now the cause why all these included Fluids, newly mentioned, or as many
others as are wholly included within a heterogeneous fluid, are not
_exactly_ of a _Spherical Figure_ (seeing that if caused by these
Principles only, it could be of no other) must proceed from some other kind
of _pressure_ against the two opposite flatted sides. This _adventitious_
or _accidental pressure_ may proceed from _divers causes_, and accordingly
must _diversifie_ the Figure of the included heterogeneous fluid: For
seeing that a body may be included either with a fluid only, or only with a
solid, or partly with a fluid, and partly with a solid, or partly with one
fluid, and partly with another; there will be found a very great variety of
the terminating _surfaces_, much differing from a _Spherical_, according to
the various resistance or pressure that belongs to each of these
encompassing bodies.

Which Properties may in general be deduced from two heads, _viz._ _Motion_,
and _Rest_. For, either this Globular Figure is altered by a _natural
Motion_, such as is _Gravity_, or a _violent_, such as is any _accidental
motion_ of the fluids, as we see in the _wind_ ruffling up the water, and
the _purlings_ of _Streams_, and _foaming_ of _Catarracts_, and the like.
Or thirdly, By the _Rest_, _Firmness_ and _Stability_ of the ambient
_Solid_. For if the including _Solid_ be of an _angular_ or any other
_irregular_ Form, the included _fluid_ will be near of the _like_, as a
Pint-_Pot_ full of _water_, or a _Bladder_ full of _Air_. And next, if the
including or included fluid have a greater _gravity_ one than another, then
will the _globular_ Form be deprest into an _Elliptico-spherical_: As if,
for example, we suppose the Circle _ABCD_, in the _fourth Figure_, to
represent a _drop of water_, _Quick-silver_, or the like, included with the
_Air_ or the like, which supposing there were no _gravity_ at all in either
of the _fluids_, or that the _contained_ and _containing_ were of the _same
weight,_ would be _equally comprest_