Conclusion.

(43.) According to the Law of Simultaneous Contrast of Colours and the insensible gradation of modification commencing from the contiguous edges of the juxtaposed coloured bands (11.), we can represent by coloured circular spaces the modifications which the principal colours tend to induce in those which are contiguous to them.

.

Take circular pieces of paper, or other material, coloured red, green, orange, blue, greenish-yellow, violet, indigo, and orange-yellow, of about one inch and a half in diameter; place each one separately on a sheet of white paper; then, with a thin wash of colour, tint the white paper around the circle, with its complementary colour, gradually weaker and weaker as the tint recedes from the coloured circle. These figures are principally intended to represent the effects of contrast in a palpable manner to those persons who, not having studied physics, yet have, nevertheless, an interest in knowing these effects.

The Red circle tends to colour the surrounding space with its complementary Green.

The Green circle tends to colour the surrounding space Red.

The Orange

The Blue

Blue.
Orange.

The Greenish-Yellow

(44.) WHITE substances contiguous to those which are coloured, appear sensibly modified when viewed simultaneously with the latter. I admit that the modification is too feeble to be determined with entire certainty, when we

are ignorant of the law of contrast; but knowing that, and seeing the modification effected by the white upon certain coloured substances, it is impossible to avoid recognising this modification in its speciality if at the same time the colours opposed to the white are not too deep.

Red and White.

(45.) Green, the complementary of Red, is added to the White. The Red appears more brilliant and deeper.

Orange and White.

(46.) Blue, the complementary of Orange, is added to the White. The Orange appears brighter and deeper.

Greenish-Yellow and White.

(47.) Violet, the complementary of Greenish-Yellow, is added to the White. The Yellow appears brighter and deeper.

Green and White.

(48.) Red, the complementary of Green, is added to the White. The Green appears brighter and deeper.

Blue and White.

(49.) Orange, the complementary of Blue, is added to the White. The Blue appears brighter and deeper.

Indigo and White.

(50.) Orange-Yellow, the complementary of Indigo, is added to the White. The Indigo appears brighter and deeper.

Violet and White.

(51.) Greenish-Yellow, the complementary of Violet, is added to the White. The Violet appears brighter and deeper.

Black and White.

(52.) Black and White, which may in some respects be considered as complementary to each other, conformably to

the law of Contrast of Tone, differ more from each other than when viewed separately: and this is owing to the effect of the white light reflected by the black (4.) being destroyed more or less by the light of the white stripe; and it is by an analogous action that White heightens the tone of the colours with which it is placed in contact.

CHAPTER V.

ON THE JUXTAPOSITION OF COLOURED SUBSTANCES WITH BLACK.

(53.) BEFORE stating the observations to which the juxtaposition of coloured and black substances give rise, we must analyse the part the two contrasts-those of Tone and of Colour-perform in the phenomenon considered in its general bearing.

The black surface being deeper than the colour with which it is in juxtaposition, the Contrast of Tone must tend to deepen it still more, while it must tend to lower the tone of the contiguous colour, for the same reason, exactly, that White, on the other hand, if juxtaposed with it would heighten it. Thus much for Contrast of Tone.

(54.) Black substances reflect a small quantity of white light (4.), and this light arriving at the eye at the same time with the coloured light of the contiguous body, it is evident that the black substances must appear tinted with the complementary of the coloured light: but the tint will be very faint, because it is manifested upon a ground having but a feeble power for reflecting light. Thus much for Contrast of Colour.

(55.) The lowering of the tone of a colour in contact with black is always perceptible; but a very remarkable fact is, the weakening of the black itself when the contiguous colour is sombre and of a nature that yields a luminous complementary, such as Orange, Orange-Yellow, Greenish-Yellow, &c.

Red and Black.

(56.) Green, the complementary of Red, uniting with the Black, causes it to appear less reddish.

The Red appears lighter or less brown, less oranged.

Orange and Black.

(57.) The complementary of Orange (Blue), uniting with the Black, the latter appears less rusty, or bluer. The Orange appears brighter and yellower, or less brown.

Greenish-Yellow and Black.

(58.) The complementary of Greenish-Yellow (Violet), uniting with the Black, the Black appears tinted Violet. The Yellow is lighter,-greener perhaps; and there are some samples of Yellow which appear weaker by their juxtaposition with Black.

Green and Black.

(59.) The complementary of Green (Red), uniting with the Black, the Black appears more Violet or reddish. The Green inclines slightly to Yellow.

Blue and Black.

(60.) The complementary of Blue (Orange), uniting with the Black, the Black becomes brighter. The Blue is lighter,-greener, perhaps.

Indigo and Black.

(61.) The complementary of Indigo (Orange-Yellow), uniting with the Black, brightens it considerably. The Indigo becomes brighter.

Violet and Black.

(62.) The complementary of Violet (Greenish-Yellow), uniting with the Black, brightens it.

The Violet is more brilliant,-lighter,-redder, perhaps.

CHAPTER VI.

ON THE JUXTAPOSITION OF COLOURED SUBSTANCES WITH GREY.

(63.) If one of the principal causes that prevent our seeing the modifications which coloured bodies tend to impart to white bodies juxtaposed with them is, the brightness of the light reflected by the latter;-on the other hand, if the feeble light reflected by black bodies, is on the contrary, less favourable to our perception of the kind of modification they experience from the proximity of coloured bodies, particularly in the case where the complementary of the body is itself not very luminous, we may imagine that Grey bodies, properly selected with respect to height of tone, will, when they are contiguous to coloured substances, exhibit the phenomena of contrast of colour in a more striking manner than either black or white substances do.

Red and Grey.

(64.) The Grey appears greener by receiving the influence of the complementary of Red.

The Red appears purer,-less orange, perhaps.

Orange and Grey.

(65.) The Grey appears bluer by receiving the influence of the complementary of Orange.

The Orange appears purer, and brighter,-yellower, perhaps.

Yellow and Grey.

(66.) The Grey appears inclining to Violet by receiving the influence of the complementary of Yellow.

The Yellow appears brighter, and less green.

Green and Grey.

(67.) The Grey appears inclining to Red by receiving the influence of the complementary of Green.

The Green appears brighter,-more yellow, perhaps.