Opticks 1717 - Up

I h2 I
than of the red to zand fg do dik in deg~~es
of Refrangibility.
X illuminated allro a litt-le circular piece of
white Paper $11 over with the kight~ of both
Prifms inrcrmixcd 1 :lnd when it 3:s illuminated
\virll the red of one !5pe&ru111 and deep
violet of the other, ii, as by the mixture of
thofe Colours to appear all over purple, I viewed
the Paper, firit at a lefs diitance, and then
at a g:‘ccat~“r, through a third+Priiin ; and as I
went from the Paper-, the refIw%d Image thereof
LXX~III~ IWXT and more divided by the unequaE.
R&-iliti~~~ of the two mixed Colours, and
at length parted into two diltin0 Images, a red
one and a violet one, whereof the violet ws
fartheft from the Paper, and therefore EL&red
the great& Rek&ion. And when that Priftn
at the Window which caiZ the ‘violet oii the Paper
\WS take11 ilLV3jr, the violet Image diGp,
peared ; but when the ot-her ‘Prifm was taken
away the red vanifl~ed: which ihen7s that thefe
two Images were nothing elk than the Lights
of the two Prifms which had been intermixed
on the purple Paper, but were parted agGn by
!heir unequal RefraCtions made in the third
Prifm through which the Paper was victwed:
This aIf0 was obfervable, t&lt if dne of “the
Prifms at the W’indow, iilppofe that which cailz
the violet on the Paper, ~7~s turned about its
’ Axis to make all the Cqlours in this order, via?
Pet, indigo, blues green, yellow, orange, red,
fall fucceflively on the Paper from that Prifnl,
the violet Inlage changed Colour accordingly,
Fuming lilcceflively to indigo, blue, greejl, yelbcny
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