Opticks 1717 - Up

”
c
$i&atiion ,of Qbli
lour fobneff eme
e edges. of the
white. And as the breadth of every Ring is,
khus augmented, the dark Ilitervals nit& be diminik’d,
until the neighbouring Rings become
continuousi and are blended, the exterior firlis
and then ,thofe ncqes the center? fo that they
can no longer be difiinguifll’d apart; but keni:
to corihm an even and uniform whitenefs;
Among a1.l the Obfervations there is none a&~
companied with fo odd circumfiances as the’
twenty fourth. Of thofe the princi al ares th4t.
in, thin Platesj which. to the naked E + ye feem of
an even , and uniform. tranfparent whi tetitifs 3
~vith~ut any terqiinations ‘of Shadowsi the: E&e+
fratiion of a Pkifm Gould make Rings of CCG
Jours appear j whereas it ufually makes Obje&
appear col&d only there where they are t&l”-
@fated: with Shadowsi or have parts tinegtiak
I luminous j, and that it fllou!d make thdei
iI ~. ings e,xceedingIy difiinff and whi’te; although
,$t.iifrial~y renders Obje&s,confufed and colour~
ed: i The C&i& of thefe things you will un&?z
4lantl b-J;confideriri~, that all the Rings of Co;
Iours are +eaIly in the Plate, when view’d withi
the n@ped Eye;, although by r’eafon of the @-eat
jxeadtli of tbeii Circumferences they So much
Interfere and ,are blended together, that thef7:
feern to confiittrte an iiniform whitenefs: But
‘when the Rays pafs through the Prifni to thti
Eye;. the Orbits of the fe8veral Colours in ev’ety
Ring, are ?efra@eds foltie rntire than othersi ticcording
to their degrees of &efi’singibility 2. By
kh:ich
,
~j-&~s tlac Ce@tir aj 6ixl’e. fi&! of’$he*
$.. RilT@