( 6*6 ) 
d y into the Line d d ; fo that the emergent Ray will 
be d d, as if the Refraction had been performed in 
the Point », and that Point was in the Surface GG, 
without any Curve at a b c d ; and all the reft as we 
confidered it before, with this Difference only, viz. 
That the Ray is bent juft as it comes out ( or rather 
when it is come out ) of the denfe Medium ; where- 
as before we confidered its Bending before it came 
into it. ' 
Of the Bending of Rays in Reflection. 
But if the Ray R a {Fig. 14) coming out of 
Glafs into Air, fhould come in fuch a Direction 
as to be wholly reflected, as it will do when the An- 
gle R*P is of 45 Degrees ; I fay the Reflection will 
not be made at the Surface GG, nor above it in 
the Glafs ; but under the faid Surface, in the Air, 
or even in a Vacuum, or any Medium lefs denfe, or 
rather lefs refractive than Glafs. 
MM reprefents the Limits of the Attraction of 
the Glafs exerted in a Direction from MM to GG 
perpendicularly, as we laid before. 
The Ray R a, moving in the Direction R r, at 
its Emerfion at a , is, for the Reafons before given, 
turned into the Direction a a ; then at into the 
Direction b b •, at c y into the Direction c c ; a z d, in- 
to the Direction d d ; at e, into the Direction e e ; 
and at f into the Direction f f parallel to G G ; 
then at g, the Ray is again turned towards the 
Glafs, by whofe Attraction changing fucceftively 
into all the Directions g g, / i, k k, and /1 ; at laft 
it re-enters the Glafs in the Direction m m making 
the 
