_On the Juxtaposition of Coloured Bodies with Grey._
(See Plate 10, Page 58.)
63. As the brilliancy of the light reflected by white bodies is one
of the principal causes which render the sight insensible to the
modifications produced in white by the juxtaposition of coloured
bodies; and, on the other hand, as the feeble light reflected from
black bodies is unfavourable to our perception of the modifications
which they sustain from the proximity of coloured bodies, especially
when the complementary of the colour of these bodies is but slightly
luminous, it may be conceived that grey bodies, judiciously selected
with regard to their depth of tone, would, by contiguity to coloured
bodies, exhibit the phenomena of contrast of colour in a more striking
manner than either black or white bodies would.
_Red and Grey._
64. Grey appears Greenish by receiving the influence of its
complementary Red.
The Red appears purer, less Orange perhaps.
_Orange and Grey._
65. Grey appears Bluer by receiving the influence of its complementary
Orange.
The Orange appears purer, more brilliant, Yellower perhaps.
_Yellow and Grey._
66. Grey appears to incline to Violet by receiving the influence of its
complementary Yellow.
The Yellow appears more brilliant, and yet less Green.
_Green and Grey._
67. Grey appears to incline to Red by receiving the influence of its
complementary Green.
The Green appears more brilliant, Yellower perhaps.
_Blue and Grey._
68. Grey appears to incline to Orange by receiving the influence of its
complementary Blue.
The Blue appears more brilliant, Greener perhaps.
_Indigo and Grey._
69. Grey appears to incline to Orange by receiving the influence of its
complementary Blue.
The Blue appears more brilliant, Greener perhaps.
_Violet and Grey._
70. Grey appears Yellowish by receiving the influence of its
complementary Violet.
Violet appears fresher, less dull.
70_a_. The grey, which was the subject of the above experiments, was
as free as possible from every colouring matter foreign to black; it
belonged to the scale of normal black (see Part II., 164)—that is
to say, it resulted from a mixture of the purest possible black and
white materials. By juxtaposition with white, it appeared deeper, and
the white appeared more pure; while by juxtaposition with black, it
appeared lighter and more rusty, and the black appeared deeper.
70_b_. One result of the complementaries of colours in juxtaposition
with grey being more perceptible than when these colours are juxtaposed
with white or black, is, that if instead of a _normal grey_, we
juxtapose a _grey, tinted_ either with _red, orange, yellow_, &c.,
these tints will be greatly heightened by the complementaries added
to them. For example, a bluish grey will receive a very perceptible
increase of blue from its proximity to orange, and a yellowish-grey
will take a perceptible green tint from the same proximity.
NOTE.—_The chemical nature of coloured substances has
no influence upon the phenomena of simultaneous contrast._
71. The chemical nature of coloured bodies in juxtaposition has no
influence upon the modifications of their colours. Whatever may happen
to be the chemical composition of the coloured bodies, provided they be
identical to the sight, they yield the same results. I need only cite
the following examples:—Indigo, Prussian blue, cobalt, ultramarine,
as nearly alike as possible, gave the same sort of modification;
orange prepared from red lead, annotto, or a mixture of woad and
madder, caused the same modification of the colours to which they were
adjacent.