DOI Page / Citation link:
https://doi.org/10.11588/diglit.19574#0122
io8 COL
more difficulty and lefs confiderably turned out of its right line
to the points between L and G.
Now each ray of light, as it differs from another in its degree
of refrangibility, fo does it differ from it in Colour; this is war-
ranted by numerous experiments.
Thofe particles, for inftance, which are moft refracted, are
found to conftitute a ray of a violet Colour, i. e. in all probabi-
lity, the moft minute particles of light, thus feparately impelled,
excite the fhorteft vibrations in the retina, which are thence pro-
pagated by the folid fibres of the optic nerves into the brain,
there to excite the fenfation of violet colour, as being the moft
dufky and languid of all Colours.
Again, thofe particles which are the leaft refracted, conftitute
a radiolus or pay of a red Colour, i. e. the largeft particles of
light excite the longelt vibrations in the retina, fo as to produce
the fenfation of a red colour, the brighteft and moft vivid of all
Colours.
The other particles, being in like manner feparated according
to their refpective magnitudes into little rays, excite the inter-
mediate vibrations ; and thus occafion the fenfation of the inter-
mediate Colours, much in the fame manner as the feveral vi-
brations of the air, according to their refpective magnitudes, ex-
cite-the fenfat ion of different founds.
To this it may be added, that not only the more diftinct and
notable Colours of red, yellow, blue, &c. have thus their rife
from the different magnitudes and refrangibility of the rays ; but
alfo the intermediate degrees or tints of the fame Colour, as of
yellow up to green, of red down to yellow, &c.
Further, the Colours of thefe little rays not being any adven-
titious modifications thereof, but connate, primitive, and necef-
fary properties, as confifting, in all probability, in the magnitudes
of their parts, muft be perpetual and immutable, i. e. cannot be
changed by any future refraction or reflection, or by any modi-
fication whatfoever.
This is confirmed by abundance of experiments ; all endea-
vours having been ufed, after feparating a coloured ray from thofe
of other kinds, to change it into fome other Colour by repeated
refractions, but to no effect.
Apparent tranfmutations of Colours indeed may be effected,
viz. where there is an affemblage or mixture of rays of different
kinds ; the component colours never appearing in their natural
hue in fuch mixtures, but alwavs allayed and tempered with each
other ; whence refults a middling kind of Colour, which by
retraction may be feparated into component ones, and thofe, af-
ter Reparation being re-mixed, return to their former Colour.
Hence the tranfmutations of Colours, by mixing thofe of dif-
z ferent
more difficulty and lefs confiderably turned out of its right line
to the points between L and G.
Now each ray of light, as it differs from another in its degree
of refrangibility, fo does it differ from it in Colour; this is war-
ranted by numerous experiments.
Thofe particles, for inftance, which are moft refracted, are
found to conftitute a ray of a violet Colour, i. e. in all probabi-
lity, the moft minute particles of light, thus feparately impelled,
excite the fhorteft vibrations in the retina, which are thence pro-
pagated by the folid fibres of the optic nerves into the brain,
there to excite the fenfation of violet colour, as being the moft
dufky and languid of all Colours.
Again, thofe particles which are the leaft refracted, conftitute
a radiolus or pay of a red Colour, i. e. the largeft particles of
light excite the longelt vibrations in the retina, fo as to produce
the fenfation of a red colour, the brighteft and moft vivid of all
Colours.
The other particles, being in like manner feparated according
to their refpective magnitudes into little rays, excite the inter-
mediate vibrations ; and thus occafion the fenfation of the inter-
mediate Colours, much in the fame manner as the feveral vi-
brations of the air, according to their refpective magnitudes, ex-
cite-the fenfat ion of different founds.
To this it may be added, that not only the more diftinct and
notable Colours of red, yellow, blue, &c. have thus their rife
from the different magnitudes and refrangibility of the rays ; but
alfo the intermediate degrees or tints of the fame Colour, as of
yellow up to green, of red down to yellow, &c.
Further, the Colours of thefe little rays not being any adven-
titious modifications thereof, but connate, primitive, and necef-
fary properties, as confifting, in all probability, in the magnitudes
of their parts, muft be perpetual and immutable, i. e. cannot be
changed by any future refraction or reflection, or by any modi-
fication whatfoever.
This is confirmed by abundance of experiments ; all endea-
vours having been ufed, after feparating a coloured ray from thofe
of other kinds, to change it into fome other Colour by repeated
refractions, but to no effect.
Apparent tranfmutations of Colours indeed may be effected,
viz. where there is an affemblage or mixture of rays of different
kinds ; the component colours never appearing in their natural
hue in fuch mixtures, but alwavs allayed and tempered with each
other ; whence refults a middling kind of Colour, which by
retraction may be feparated into component ones, and thofe, af-
ter Reparation being re-mixed, return to their former Colour.
Hence the tranfmutations of Colours, by mixing thofe of dif-
z ferent