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of Rain, is alio fi^m hence evident. For.thofc drops, which re- 
fract the Rays, difpofed to appear purple^ in greateft quantity to 
the Spcdiators eye, refra£t the Rays of other forts fo much lefs, 
as to make them pafs befide it 5 and fuch are the drops on the in- 
fide of the Primary Bow, and on the ouifide of the Secon^iary or 
Exteriour one. So thofe drops, which refraft in greateft plenty 
the RaySj apt to appear red, toward the Spedtators eye^ refraft 
thofe of other forts lo much more,as to make them pafs befide it; 
and luch are the drops on the exteriour part of the Primary, and 
interiour part of the Secondary Bow. 
i I. The odd Phsenomena^of an infufion of Lignum 'Nephriticum^ 
Leaf grJdj Fragments of coloured glafs^ and lorae other tranfparently 
coloured bodies, appearing in one pofuion of one colourjand of 
another in another^ are on thefe grounds no longer riddles* For, 
thofe are fubftances apt to reflect one fort of light and tranfmit 
another 5 as may be feen in a dark room, by illuminating them 
with fimilar or uncompounded light* For, then they appear of 
that colour only, with which they are illuminated, but yet in one 
pofitionmore vivid and luminous than in another, accordingly 
as they arc difpofed more or lefs to reflecSt or tranfmit the incident 
colour* 
12. From hence alfo is manifeft the reafon of an unexpeded 
Experiment, which Mn Hoo\ fbmewhere in his Micrography re- 
lates to have made with two wedg-like tranfparent vefTels^fiird the 
one with a red, the other with a blew liquor : namely,that though 
they were feverally tranfparent enough, yet both together became 
opake } Forjif one tranfmitted only red,and the other only blew, 
no rays could pafs through both. 
13. I might add more inftances of this nature, but I fhall con* 
ckde with this general one, that the Colours of all natural Bodies 
have no other origin than this, that they are varioufly quah6ed to 
refl[e<9: one fort of light in greater plenty then another. And this 
I have experimented in a dark Room by illuminating thofe bodies 
with uncompounded light of divers colours. For by that means 
anybody may be made to appear of any colour. They have 
there no appropriate colour, but ever appear of the co- 
lour of the light caft upon them, but yet with this difference, 
that they are moft brisk and vivid in the light of their own day- 
light-coloar. Minium appeareth there of any colour indifferently. 
With which 'cis illuftrated, but yet moft luminous in red, and fo 
