Opticks 1717 - Up

nomena proceeding from them, and proving
the Explanations.
In the tW0 firit Books of thefe Opticks, 1
proceeded by this L4nalyfis to difcover and prove
the original Differences of the Rays of Light in
refpeA of Refrangibility, Kcflexibility, and Golow,
and, their alternate Fits of eafy Metlcxiou
and ea,fy Traufmiilion , and the Properties of
Bodies 9 both opake and pellucid, on which
their Reflexions and Colours depend. And
rhefe Difcoveries being proved, may be afliuned
in the Method of Compofition “for explaining
the Phaenomena arifing tiom them: An In.
fiance of which Method I gave in the End of
the firit Rook. Tn this third Eook I have only
begun the Anal fis of what remains to bc diir
cover’d about E ight and its M‘eAs upon the
Frame of Natur?, hinting feveral things ahout
it, and leaving the Hints to be ex;zmin’d and
improved' by the farther Experiments and Obfervations
of fuch as are inquifitive. And if
natural Philofophy in all its Parts, b purfuing
this Method., ihall at length be per P etted, the
Bounds of moral Philofophy mill be ali’o enlarcd.
For fo far as we can lmo~ by natural
f! llilofophy v,+at is the firit Cauii, what Power
he has over L$ and what Benetits !vc reccivc
from hiIn, fo far 0~1rDuty towards him, AS \x-ell
as that towards one another, will appear to us
by the Light of Nature. And no doubt, if the
WorAlip of falf’e Gods had not blinded theJ+feathen,
their moral Philoibphy would have gOllC
farthg.r than to the four Cardinal Virtuezfl;ai
i