C 6 no ) 
and only de^compounded of thofe two. For wjia^ce, the 
Or^^^e was compounded of Red, Orange, Yellow and fome 
Green 5 and the^/Vrt^jof Violet/uH Blew^light Blew^aod fome 
GreeHjWkh all their Intermediat degrees '-^ and conftqueotly 
the Orange and Blew together made an Aggregate of all co- 
lors to conftitute the White. Thus^if one mix red^orange and 
yellow Powders to make an Orange 5 and grcenjblew arid vi- 
olet colors to make a Blew 5 and laftly, the two mixtures, to 
make a Grey; that Grey, though de«compounded of no more 
than two Mixtures^ is yet compounded of all the fix PowderSj 
as truly as if the powders had been all mixtat once. 
This isfo plain, that I conceive there can be no further 
fcruple 5 efpecially toihcm who know how to ex imine^ whe- 
ther a colour be fimpie or compounded.aod of what colors it 
is compounded 5 which having explained in another place, I 
need not now repeat- Ifthercfort N. would conclude any thing 
he muftfhew, how Whire may be produced out of two Vn^ 
compounded colors , which when he hathdone, 1 Vvill further 
tell hiiDjwhy he can conclude nothing from that.But I believe, 
there cannot be found an Experiment of that kind | becauic ' 
as I remember,! once tryed^by gradual fucceffion^the mixture 
ofaH paifsofUo-compounded colors 5 and, though fome of 
them were paler, and nearer to White, than others, yet none 
could be truly catrd White. But it being fome years fince this 
tryal was made, 1 remember not well the circumftances, and 
therefore recommend it to others to be tryed again* ^ 
in thelaftplace, had I thought, the Diftinftnefs of the Pi- 
flure.which (for tnftanceyz Twelffoot Objed glafs cafts into 
e darkened roqm^to be fo contrary to me as N. is pleaf^d to af- 
firm,! fliould have waved my Theory in that point before ! 
propounded it. For, that I had thought 00 that difficuky , 
Numb 8^ youmay eafilyguefs by an cxpreffion, fome- 
* ^here inpy firft Letter ^ toihis pijrpofiiThat 
I wondc r^d ^how Telercopes could be brought 
to fb grr^at perfeftioo by Refrai^ipns wfiich we^e fo [rregub^ 
But^tptakeawayihf difficulty,! muft acquaint you./ri?5fhaCi 
though I put the greateft Lateral error of the rays from on^ 
another to be about ^ of the Giaflis diameter y y^t their grea- 
ter crfprifr^m the Points on which they ought to foll^ will be 
but 
