parably with the perspective of the shores.
The most beautiful of all results that I know in mountain streams is
when the water is shallow, and the stones at the bottom are rich
reddish-orange and black, and the water is seen at an angle which
exactly divides the visible colors between those of the stones and that
of the sky, and the sky is of clear, full blue. The resulting purple,
obtained by the blending of the blue and the orange-red, broken by the
play of innumerable gradations in the stones, is indescribably lovely.

146. All this seems complicated enough already; but if there be a strong
color in the clear water itself, as of green or blue in the Swiss lakes,
all these phenomena are doubly involved; for the darker reflections now
become of the color of the water. The reflection of a black gondola, for
instance, at Venice, is never black, but pure dark green. And, farther,
the color of the water itself is of three kinds: one, seen on the
surface, is a kind of milky bloom; the next is seen where the waves let
light through them, at their edges; and the third, shown as a change of
color on the objects seen through the water. Thus, the same wave that
makes a white object look of a clear blue, when seen through it, will
take a red or violet-colored bloom on its surface, and will be made pure
emerald green by transmitted sunshine through its edges. With all this,
however, you are not much concerned at present, but I tell it you partly
as a preparation for what we have afterwards to say about color, and
partly that you may approach lakes and streams with reverence,[38] and
study them as carefully as other things, not hoping to express them by a
few horizontal dashes of white, or a few tremulous blots.[39] Not but
that much may be done by tremulous blots, when you know precisely what
you mean by them, as you will see by many of the Turner sketches, which
are now framed at the National Gallery; but you must have painted water
many and many a day--yes, and all day long--before you can hope to do
anything like those.

147. III. Lastly. You may perhaps wonder why, before passing to the
clouds, I say nothing special about _ground_.[40] But there is too much
to be said about that to admit of my saying it here. You will find the
principal laws of its structure examined at length in the fourth volume
of Modern Painters; and if you can get that volume, and copy carefully
Plate 21, which I have etched after Turner with great pains