Opticks 1717 - Up

PRoi'.
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The ifW+tZ Of Bodies aid their her/&f mz$
910t be lefs th of fonze dq%ite bjgzeJs, ta
reder thm o&de and cohir’d. .
0 R the opakefi Bodies, if. their parts be
fubtily divided, (as Metals by being diGoIin
acid M~~~TuIx, EL*.) become p&e&-
ly tranfparent. And you may alfo remember,
that in the eighth Obfervation there w’as no
fenfible reflexion at the Superficies of rhe ObjeA-glaffes
where they were very near one allother,
though they did not abfolutely touch.
And in the r?th Obfervation the Reflexion of
- the Water-bubble where it became thinneflk was
almofi inf@ible, fo as to cauk very black Spots,
to appear on the .top of the.Bubble by the want
of refleCted Light.
On the& grounds .I perceive it is that Water,
Salt, Glafs? ‘Stones, and fuch like Subfiances Y
aie tranfparent. For, upon divers Confideia- :’
tions, they .feem to be as full of POES or kiterf&es
between their parts as other Bodies ale,
but yet their Parts and Interitices to, be too
fmall to cauk-Reflexions in their common Surfaces,
.