in interruption, causing a little confusion in
the image below, but entirely indistinguishable as leaves,--and even
their color unknown and unperceived. Unless you think of them, you will
not even feel that anything interrupts your sight, so excessively
slight is their effect. If, on the other hand, you make up your mind to
look for the leaves of the duckweed, you will perceive an instantaneous
change in the effort of the eye, by which it becomes adapted to receive
near rays--those which have only come from the surface of the pond. You
will then see the delicate leaves of the duckweed with perfect
clearness, and in vivid green; but while you do so, you will be able to
perceive nothing of the reflections in the very water on which they
float--nothing but a vague flashing and melting of light and dark hues,
without form or meaning, which, to investigate, or find out what they
mean or are, you must quit your hold of the duckweed, and plunge down.

Sec. 3. Morbid clearness occasioned in painting of water by distinctness of
reflections.

Sec. 4. How avoided by Turner.

Sec. 5. All reflections on distant water are distinct.

Hence it appears, that whenever we see plain reflections of
comparatively distant objects, in near water, we cannot possibly see the
surface, and _vice versa_; so that when in a painting we give the
reflections with the same clearness with which they are visible in
nature, we presuppose the effort of the eye to look under the surface,
and, of course, destroy the surface, and induce an effect of clearness
which, perhaps, the artist has not particularly wished to attain, but
which he has found himself forced into, by his reflections, in spite of
himself. And the reason of this effect of clearness appearing
preternatural is, that people are not in the habit of looking at water
with the distant focus adapted to the reflections, unless by particular
effort. We invariably, under ordinary circumstances, use the surface
focus; and, in consequence, receive nothing more than a vague and
confused impression of the reflected colors and lines, however clearly,
calmly, and vigorously all may be defined underneath, if we choose to
look for them. We do not look for them, but glide along over the
surface, catching only playing light and capricious color for evidence
of reflection, except where we come to images of objects close to the
surface, which the surface focus is of course adapted to receive; and
these