( ^oBs ) 
B^/^ appearcth indijflFercntly of any colour with which *tisilluftra<^ 
ted, but yet moft luminous in blew. And therefore Minium re- 
fledeth Rays of any colour, but moft copioufly thofe indued with 
red ; and confequently when illuftrated with day-lighr, that is, 
with all forts of Rays promifcuoufly blended^ thole qualified with 
red (hall abound moft in the refieifted light, and by their preva* 
lence caufe it to appear of that colour* And for the fame reafon 
Bife^ refleding blew moft copioufly, fliall appear blew by the ex^ 
cefs of thofe Rays in its rcfledled light 5 and the like of other bo^ 
dies* And that this is theintire and adequate caufe of their co* 
lours, is manifeft, becaufe they have no power to change or alter 
the colours of any fort of Rays incident apart, but put on all co-* 
lours indifferently, with which they are inlightned. 
Thefe things being fo, it can be no longer difputed, whether 
there be colours in the dark, nor whether they be the qualities 
of the objeds we fee, no nor perhaps, whether Light be a Body^ 
For, fince Colours are the g'Wiif/V/ of Light, having its Rays for 
their intire and immediate fubjeft, how can we think thofe Rays 
qualities alfo, unlefs one quality may be the fubjedk of and fuftaia 
another ; which in effe<5t is to call it Subftame. We fliould n®t 
knowBodies for fubftances^were it not for their fenfible qualities, 
and the Principal of thofe being now found due to fomething 
elfe, we have as good reafon to believe that to be a Subftance 
alfo. 
Befides j whoever thought any quality to be a heterogeneom ag- 
gregate, fuch ss Light is diftovered to be. But, to determine 
more abfoluteiy, what Light is, after what manner refraded, and 
by what modes or adiions it produceth in our minds the Phan- 
tafffls of ColourSj is not fo cafic^ And I fhall not mingle con- 
jedlures with certainties. 
Reviewing what I have written, I fee the difcourfe it felf will 
lead to divers Experiments fujffieient for its examination : And 
therefore I fhall not trouble you further, than to defcribeone of 
thofe,which I have already infiouated. 
In a darkened Room make a hole in the (but of a window, 
whofe diameter may conveniently be about a third part of an 
inch, to admit a convenient quantity of the Suns light : And there 
place aclear and colourlefs Prifme, to refraft the entring light 
towards the further part of the Room^whieb^as I faid^will thereby 
be diffufed into an oblong coloured Image. Then place a Le?js of 
H h h h 2 about 
