umber of gradations between such a sobered high light and the deepest
shadow, which we can between this and white; and as these gradations are
absolutely necessary to give the facts of form and distance, which, as
we have above shown, are more important than any truths of tone,[17]
Turner sacrifices the richness of his picture to its completeness--the
manner of the statement to its matter. And not only is he right in doing
this for the sake of space, but he is right also in the abstract
question of color; for as we observed above (Sect. 14,) it is only the
white light--the perfect unmodified group of rays--which will bring out
local color perfectly; and if the picture, therefore, is to be complete
in its system of color, that is, if it is to have each of the three
primitives in their purity, it _must_ have white for its highest light,
otherwise the purity of one of them at least will be impossible. And
this leads us to notice the second and more frequent quality of light,
(which is assumed if we make our highest representation of it yellow,)
the positive hue, namely, which it may itself possess, of course
modifying whatever local tints it exhibits, and thereby rendering
certain colors necessary, and certain colors impossible. Under the
direct yellow light of a descending sun, for instance, pure white and
pure blue are both impossible; because the purest whites and blues that
nature could produce would be turned in some degree into gold or green
by it; and when the sun is within half a degree of the horizon, if the
sky be clear, a rose light supersedes the golden one, still more
overwhelming in its effect on local color. I have seen the pale fresh
green of spring vegetation in the gardens of Venice, on the Lido side,
turned pure russet, or between that and crimson, by a vivid sunset of
this kind, every particle of green color being absolutely annihilated.
And so under all colored lights, (and there are few, from dawn to
twilight, which are not slightly tinted by some accident of
atmosphere,) there is a change of local color, which, when in a picture
it is so exactly proportioned that we feel at once both what the local
colors are in themselves, and what is the color and strength of the
light upon them, gives us truth of tone.

Sec. 19. The perfection of Cuyp in this respect interfered with by numerous
solecisms.

For expression of effects of yellow sunlight, parts might be chosen out
of the good pictures of Cu