( 50^^ ) 
mint. But tfiis, I conceive, is enough £0 enforce it, and fo to de^ 
cide the controverfy. How-ever, I ftali now proceed to (hew fome 
other ways of producing Whkenefs by mixmres\ fince I perfwade my 
felf, that this AfTertion above the reft appears Paradoxical, and is 
with moft difficulty admitted* And becaufe the Animadverfor defires- 
an inftance of it in Bodies of divers colours^ I (hall begin with that. 
But in order thereto itraufl: be confider'd, that fuch colour d Bodies 
refled but fome part of the Light incident on them as is eviden!: 
by the 1 3 Propofition : And therefore the Light refleded frona an Ag« 
gregat of them will be much weakned by the lofs of many rays; 
Whence a perfed and ifitenfe Whitenefs is not to be expeded» but 
rather a Colour between thofe of Light and Shadow, or fuch a 
Gray or Dirty " ' r as may be made by mixing White and Black 
together. 
And tbaifuch a Coiour will refult, may be colleded from the 
colour of D^/ found in ^^v^ry corner of an houfc, which hathbeea 
obfervM to conlift of many co'ourM particles. There may be aifo 
produced the like Dirty colour by mixing feveral Palmers colours 
together. And the fame may be effedcd by Painting a To^ (fuch 
as Boys play withj of divers colours. For, when it is made 
to circulate by whipping it, it will appear of fuch a dirty co» 
iour» 
Now, the Compounding of thefie colours is proper to my pur- 
pofe, becaufe they differ not from Whitenefs in the Species oi co-^^ 
lour, but only in ^^^?'^^ of Luminoufnefs which (did not the 
imadverfor concede it) I might thus evince. A beam of the Suns 
Light being tranfraitted into a darkned room, if you illuminate a 
Jheet ofWhite Paper by that Light, refleded from a body of a- 
. ny colour, the paper will always appear of the colour of that bo- 
dy, by whofe refleded light it is illuminated. If it be ared bo« 
^dy, the paper will be red, if a green body, it will be green j and fo 
of the other colours. The reafon is, that the fibers or threds, of 
which the paper eonfifts, are all tranfparent and fpecular and fuch 
" fubftances are known to refled colours without changing them. To 
know therefore, to what Species colour a (7r^j belongs, place a- 
ny Gray body(fuppofe a Mixture o^ Painters coloHrs^)\n the faid Lights 
and the paper, being illuminated by its reflexion, fliall appear White* 
And the fame thing will happen, if it be illuminated by reflexioii 
from a^/^i^t^^ubftance, 
Thefc therefore are all of one Species ; but yet they feem diftin- 
guiflit not only by degrees Lurainoufnefs, but alfo by fome other 
Inequalities, whereby they become more harfii or pleafant» And th;: 
diftindion feeras to be, thn Greys and perhaps Blackj are made by a • : 
uneven defedof Light, confifting as it were of many little vein 
flrcams, which differ either in Luminoufnefs or in the Unequal 
^ ^ Mnimmra " ftrilu : 
