64 
MicroGRAPHIA. 
enter the eye, to have their pulfes made oblique to their progreffion, and 
confequently each Ray to have potentially fuperinduc'd two proprieties, 
or colours,viz. a Red onthe one fide, and a B/ve on the other, which nots _ 
withftanding are never actually manifeft,butwhen this or that Ray hasthe 
oneor the other fide of it bordering on a dark or unmov'd medium,there: 
fore as foon as thefe Rays are entred into the ‘eye,and fo have one fide of 
each of them bordering on a dark part of the humours of the eye, they 
will eachof them actually exhibit fome colour; therefore ADC the pro- 
duction G A CH will exhibit a B/ve,becaufe the fide C D is adjacent tothe 
~ dark medinmC QD C,but nothing ofa Red,becaufe its fide A Dis adjacent 
to the enlightned medium A DF A: And all the Rays that from the points 
of the luminous body are collected‘on the parts of the Ketiva between D 
and F fhall have their Blue fo much the more diluted by how much the far+ 
ther'thefe points of collection are diftant from D towardsF ; and the Ray 
AF Cthe production of KC Al, will exhibita Red, becaufethe fide AF 
is adjacent to the dark or quiet wedium of theeye APF A; but nothing — 
ofa Blue,becaufe its fide C F is adjacent to the enlightned medium CF DC, 
and all the Rays from the intermediate parts of the luminous bedy that 
are colleéted between F and D fhall have their Red{o muchthe more di- _ 
luted, by how much the farther they are diftant from F towards D. 
_ ov Now,becaufe by the refraction in the Corzea,and fome other parts of the 
whofe weakeft follows. 
‘eye, the fides of each Ray, which before were almoft paralleljaremade 
to converge and meet in a point at the bottomofthe eye, therefore that 
fide of thepul/e which preceded before thefe refractions, fhall firfttouch 
the Retiza, and the other fide laft. And therefore according as this or _ 
that fide, or end of the pulfe fhall be impeded, accordingly will the i#- 
preffions on the Retina be varied; therefore by the Ray GACH ree 
fratted by the CorneatoD there fhall be onthat point a ftrokeor impre® 
fion confus'd, whofe weakeft end, namely, that by the line CD thall pre- 
cede, and the f{tronger, namely, that by the line AD fhall follow. And 
by theRay KCAT refracted to F, there fhall be on that part aconfus'd 
{troke or ind jorian eereres ftrongeft part,namely,that by the line CF thal 
precede, and whofe weakeft or impeded, namely, that by the line AF 
fhall follow, and all the intermediate points between F and D will re- - 
ceive impreflion fromthe coxverg'd Rays fo much the more like the im- 
ig on F and D by how much the nearer they approach that 
or 
_ Fromthe confideration of the proprieties of which impreffions,we maj 
collect thefe fhort definitions of Colbari : That Blue riper impreffion 7” 
the Retina of an oblique and confus d pulle of light, whofe weakeft part pre- 
cedes, and whofe  ftrongest follows. And, that Red # an imprelfion onthe Re- 
tzna of an oblique and confus'd pulfe of light, whofe ftrongeft part precedesand 
_ Which proprieties,as they have been already manifefted,in the Prifne 
and falling drops of Rain, to be the caufes of me colours ie generated, 
may be ealily found to be the efficients alfo of the colours appearing in , 
thin laminated tran{parent bodies: for t ication i is has 
Se ees paren ¢s; for the explication of ees Zt 
