First, They _unite_ the parts of a fluid to its _similar_ Solid, or keep them _separate_ from its _dissimilar_. Hence _Quick-silver_ will (as we noted before) _stick_ to _Gold_, _Silver_, _Tin_, _Lead_, &c. and _unite_ with them: but _roul_ off from _Wood_, _Stone_, _Glass_, &c. if never so little scituated out of its _horizontal level_; and _water_ that will _wet salt_ and _dissolve_ it, will _slip_ off from _Tallow_, or the like, without at all _adhering_; as it may likewise be observed to do upon a _dusty_ superficies. And next they cause the parts of _homogeneal fluid_ bodies readily to _adhere_ together and _mix_, and of _heterogeneal_, to be exceeding _averse_ thereunto. Hence we find, that _two_ small _drops_ of _water_, on any superficies they can roul on, will, if they chance to touch each other, _readily unite_ and _mix_ into one 3d _drop_: The like may be observed with two small _Bowls_ of _Quick-silver_ upon a Table or Glass, provided their surfaces be not _dusty_; and with two drops of _Oyl_ upon fair water, _&c._ And further, _water_ put unto _wine_, _salt water_, _vinegar_, _spirit_ of _wine_, or the like, does immediately (especially if they be shaken together) _disperse_ it self all over them. Hence, on the contrary, we also find, that _Oyl of Tartar_ poured upon _Quick-silver_, and _Spirit of Wine_ on that _Oyl_, and _Oyl of Turpentine_ on that _Spirit_, and _Air_ upon that _Oyl_, though they be stopt closely up into a Bottle, and _shaken_ never so much, they will by no means long suffer any of their bigger parts to be _united_ or included within any of the other Liquors (by which recited Liquors, may be plainly enough represented the four _Peripatetical Elements_, and the more subtil _Æther_ above all.) From this property ’tis, that a drop of _water_ does not mingle with, 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_.