Opticks 1717 - Up

very ftrongly. And for explaining how this
may be, lbnle 11avc invented hooked A tams,
which is begging the Queition ; and others tell
us that Hodies arc glued together by refi, that
is, hy an occult Qualit\,, of rather by nothing ;
and others, that they ikick together by confpiring
Motions, that is, by rcIativc reitVatnongff:
rhemklves. I had ~-z&r infer from their ,Coh&on,
that their Particles attralt one another
by forne Force, which in immediate Contaa IS
excecdi.ng ittong , at fmall difiances performs
the chymical Operations above mention’d, and
reaches not ik from the Particles with any fenfible
Et&.%
All Eodies Teem to be compofed of hard Particles
: For otherwife Fluids would not congeal ;
as Water, Oils, Vinegar, and Spirit or Oil of
Vitriol do by freezing; Akrcury by k’umes of
Lead ; Spirit of Nitre and Mercury, b difT’blvine;
the Mercury and evaporating the F ilegm ;
Spirit of & ine and Spirit of Urine, by dci-legm-
Ing and mi:Gns them ; and Spirit of Urine and
S&-it .of Salt, by fubliming them cogether to
make Sal-armoniac. Even the Rays of Light*
feem to be hard Bodies ; for otherwik they
would not retain diCerent Propel-tics in their
different Sides. And therefore Hardnefs may
be reckon’d the Property of all uncompounded
Matter. At leait, this feeems to be as evident
as the univerM Impenetrability of Matter. For
all Bodies, i‘o f?tr as Experience reaches, are either
hard, or may be harden’d ; and we have
,no other Evidence of univerfal Tmpcnetrability,
-befides a large Experience without an expcriqnental