( <5o5 ) 
“ ^ ion of r * he Parts of the painted Paper to the Sur- 
“ *' lce of the Lens.” But in my Account of the Ex- 
periment in the T hilofophical TranfaCHons, I men. 
tioned particularly that the Axis of the Lens was per- 
pendicular to the Image of the Card, and therefore 
there could be no different Obliquity, as is objected. 
That though he found the SpeElrum of Colours 
produced by the Prifm in a dark Room tolhorten by 
Degrees, and at laft become round and colourlefs 
(that is white) when viewed by another Prifm, in 
“ the fame manner that Sir Ifaac Newton had made 
the Experiment; yet it did not convince him of the 
different Refrangibility of the Rays; becaufe when 
he had caufed an Image to be painted upon a Paper 
like the Spectrum from the Prifm, and enlightned it 
“ by the direct Light of the Sun, it did not become 
“ round and white when viewed through a Prifm as 
“ th f °ther Spectrum did.” But he did not confider 
the Imperfedion of Painters Colours, nor remember 
that the Surfaces of Bodies, whether of a natural or a 
painted or died Colour (fuch as he calls permanent Co~ 
lours') when expofed to any coloured Light, will re- 
flea that Colour which falls upon them, and appear to 
be of no other, only that they will feem moil vivid in 
that Colour which they bear in openDay : and 
therefore that if the Sun’s Light con fob of RaVs dif- 
ferently refrangible and producing different Colours 
(according to Sir Ifaac Newton) the Prifm muft f epa l 
rate the Light reflected from every one of the painted 
Colours, and could not bring them together, becaufe 
they were by no means Ample Colours, df therefore 
he had reafoned right, the firfl Experiment would have 
proved Su lfaac’s Doctrine, and the laft would have 
E I i i 1 confirm’d 
