n to mix the
sienna and white; though, of course, the process is longer and more
troublesome. Nevertheless, if the forms of touches required are very
delicate, the after glazing is impossible. You must then mix the warm
color thick at once, and so use it: and this is often necessary for
delicate grasses, and such other fine threads of light in foreground
work.

172. C. Breaking one color in small points through or over another.

This is the most important of all processes in good modern[48] oil and
water-color painting, but you need not hope to attain very great skill
in it. To do it well is very laborious, and requires such skill and
delicacy of hand as can only be acquired by unceasing practice. But you
will find advantage in noting the following points:

173. (_a._) In distant effects of rich subject, wood, or rippled water,
or broken clouds, much may be done by touches or crumbling dashes of
rather dry color, with other colors afterwards put cunningly into the
interstices. The more you practice this, when the subject evidently
calls for it, the more your eye will enjoy the higher qualities of
color. The process is, in fact, the carrying out of the principle of
separate colors to the utmost possible refinement; using atoms of color
in juxtaposition, instead of large spaces. And note, in filling up
minute interstices of this kind, that if you want the color you fill
them with to show brightly, it is better to put a rather positive point
of it, with a little white left beside or round it in the interstice,
than to put a pale tint of the color over the whole interstice. Yellow
or orange will hardly show, if pale, in small spaces; but they show
brightly in firm touches, however small, with white beside them.

174. (_b._) If a color is to be darkened by superimposed portions of
another, it is, in many cases, better to lay the uppermost color in
rather vigorous small touches, like finely chopped straw, over the under
one, than to lay it on as a tint, for two reasons: the first, that the
play of the two colors together is pleasant to the eye; the second, that
much expression of form may be got by wise administration of the upper
dark touches. In distant mountains they may be made pines of, or broken
crags, or villages, or stones, or whatever you choose; in clouds they
may indicate the direction of the rain, the roll and outline of the
cloud masses; and in water, the minor waves. All noble effects of dark
atmosphere are