and the chomldes^ while they are in thek natural ftate, as I fliall 
do in the following Experiment. 
Jplace by night alighted Candle very near your Eies^andcaufe 
a dog', diftant from the candle 8 or lo paces, to look upoiv 
you, then you (hall fee in his eyes, alight fufficiently bright, 
which I hold to proceed from the reflexion of the light of the 
Candle, whofe image is painted on the Choroeides of the dog, 
which having much whitenefs andlufter caufes this very ftrong 
reflexion 5 for if it proceeded from the Chryftallinc or Retina,, 
the fame appearance would be feen in the Eye^ of Men, Birds, 
and other animals, who have the Choroeides /bhck , which is 
not found fo by us. It is therefore manifeft by this Experiment, 
that the luminous rayesdo pafs with a great deal of force as far 
as ih^ choroeides^ and that the-i^^^/>4 receives very little ira- 
pi "fljon. Now this appearance is made in this manner: The 
little pi^ureof the candle which is upon the choroeides of the 
dog, (Where is the Focus of theChryftalline and other humours 
togethk^ fending rayes back through thefe humours, makes its 
reciprocal Ji^c/^ towards the candkjand by confequence the eyes 
which are near to the point, where tliefe rayes do reunite , ought 
to fee the Chryftalline of the dog very much illuminated. They 
that are skilled in Opticks know the demonftration: and there 
is aa effedJ:,^ wholy like unto this, to be feen by a very eafy Ex- 
periment. 
Place a round Glafs-bottle, full of very clear water^'S.or los. 
paces from a Candle, and put behind the bottle, at near the di- 
ftance of itsSemidiameter, a white paper,, in fuch manner that 
one may fee the light of the Candle, which hath paffed thorow 
the bottle, reunited in a little fpace upon the Paper 5 then theVj 
who have their eyes near the Candle, fliall fee the bottle full of 
light, which will difappear,^ if you hold the paper either nearer 
to, or farther from the bottle. And if one hold a fmall lighted, 
wax-candle in the place of the Paper, and you hold your 
eye in the place of the former candle, you fliall fee the bottle 
yet more enlightned then it was before: And one mayeafily 
judge, that the light which appeareth iathe dogs eye, proceed- 
eth from alikecaufe. The fame experiment maybe made in 
the 
