52. Black and white, which may be considered in some respects complementary to each other, become, conformably to the law of contrast of tone, more different than when seen separately. This results from the effect of the white light, which is reflected by the black (4), being more or less destroyed by the light of the white stripe. By an analogous action, the white heightens the tone of the colours to which it is contiguous. CHAPTER V. _On the Juxtaposition of Coloured Bodies with Black._ (See Plate 9, Page 54.) 53. A black surface being deeper than that which is contiguous to it, the contrast of tone tends to deepen it still more, while it tends to lower the tone of the contiguous colour; as on the other hand white, placed in juxtaposition with it, would heighten it. So much for contrast of tone. 54. Black surfaces reflect a small quantity of white light (4), and this falling upon the retina simultaneously with the coloured light of a contiguous body, it is evident that the black surface must appear tinted with the complementary of the coloured light; but it will be a weak tint, since it is displayed upon a ground which has but a feeble power of reflecting light. So much for the contrast of colour. 55. The lowering of the tone of the colour contiguous to the black is constantly observed; but a very remarkable fact is the weakening of the black itself, when the contiguous colour is deep, and of a nature to give a luminous complementary, as orange, orange-yellow, greenish-yellow, &c. _Red and Black._ 56. Green (the complementary of Red), when placed by the side of Black, makes it appear Reddish. The Red looks clearer, partaking less of Orange. _Orange and Black._ 57. A Blue (the complementary of Orange), when placed by the side of Black, causes it to appear less brilliant, or somewhat rusty, while Orange by the side of Black appears more brilliant in colour. _Greenish-Yellow and Black._ 58. Greenish-yellow (the complementary of Violet), when placed by the side of Black, gives it a Violet tint, whilst the Greenish-yellow becomes clearer and more Green; but there are some kinds of Yellow which are weakened by the side of Black. _Green and Black._ 59. Red (the complementary of Green), when placed by the side of Black, causes the Black to appear more Violet or Reddish; whilst Green by the side of Black becomes slightly Yellower. [Illustration: PLATE V.] _Blue and Black._ 60. Orange (the complementary of Blue), when placed by the side of Black, causes it to appear brighter, while the Blue becomes clearer and somewhat Greener. _Indigo and Black._ 61. Orange-yellow (the complementary of Indigo), placed by the side of Black, causes it to look much brighter. The Indigo also appears brighter. _Violet and Black._ 62. Violet (the complementary of Greenish-yellow), when placed by the side of Black, lightens it up; whilst the Violet becomes more brilliant and clear, and somewhat Reddish. CHAPTER VI.