Opticks 1717 - Up

the nvs of bJ&$it 1 wikv$bid its led
PUTTS; md thojt? US well SwceJJive ha t d e
yi23y2t h3 US C03m3p0322ry. in @Vera2 Lhe~.
For ,it is manifeit that Light COllfifb of par;s
both Succeffive and Contemporary ; pecavfe In
the fk-ne “place you may stop that which comes
one moment, asd let pafs that which comes prc-
Eently after ; and in the fame time you may
fiog it in any one place, atid let @ pa$ in any
other. For that part of Light which IS fipt
cannot be the fame with that’ which is let pai’s.
The leaPi Li& or part of Light,whi+ may
e ilo@ alone without the-r& of the Light, *or
ropogated alone, or do or buffer any thing alone
which the refi of the,.Light doth ~f.l’~t or &fks
note I call a Ray of.Llght.
DEFIN.
RefrnigiCi&y of the Rdys of Light, is their
0Jtion to be refr&ed or tuned 0iG of itheb
iu p$?kg oivt of one trav&ure?zt Body al
Me&m irzto another. A&d a gretizer or I%JJ Ref~iUl@bility
OJr Ruys, is their DiSpoj$ian $0 be
&wzedmore or leJS oat of their Wiy in Like .hcidences
OB .&e&me .Medz’zm, Mathematicians. g
tif?aUy confider the Rays of Light to be Lines
$eachlng from the luminqus Body tb the Body
Illuminated, and the refraQion of thok Rays to.
be the bending or breaking of thok lines ik
i
r their
k4 i
II.