adjacent to the dark or quiet _medium_ of the eye APFA, but nothing of a
_Blue_, because its side CF is _adjacent_ to the enlightned _medium_ CFDC,
and all the Rays from the intermediate parts of the luminous body that are
collected between F and D shall have their _Red_ so much the more diluted,
by how much the farther they are distant from F towards D.

Now, because by the refraction in the _Cornea_, and some other parts of the
eye, the sides of each Ray, which before were almost parallel, are made to
_converge_ and meet in a point at the bottom of the eye, therefore that
side of the _pulse_ which preceded before these refractions, shall first
touch the _Retina_, and the other side last. And therefore according as
this or that side, or end of the pulse shall be impeded, accordingly will
the _impressions_ on the _Retina_ be varied; therefore by the Ray GACH
refracted by the _Cornea_ to D there shall be on that point a stroke or
impression confus'd, whose weakest end, namely, that by the line CD shall
precede, and the stronger, namely, that by the line AD shall follow. And by
the Ray KCAI refracted to F, there shall be on that part a confus'd stroke
or impression, whose strongest part, namely, that by the line CF shal
precede, and whose weakest or impeded, namely, that by the line AF shall
follow, and all the intermediate points between F and D will receive
impressions from the _converg'd_ Rays so much the more like the impressions
on F and D by how much the nearer they approach that or this.

From the consideration of the proprieties of which impressions, we may
collect these short definitions of Colours: That _Blue is an impression on
the Retina of an oblique and confus'd pulse of light, whose weakest part
precedes, and whose strongest follows._ And, that _Red is an impression on
the Retina of an oblique and confus'd pulse of light, whose strongest part
precedes, and whose weakest follows._