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 colour 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.

C. Breaking one colour in small points through or over another.

This is the most important of all processes in good modern[241] oil and
water-colour 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:

(_a._) In distant effects of rich subjects, wood, or rippled water, or
broken clouds, much may be done by touches or crumbling dashes of rather
dry colour, with other colours afterwards put cunningly into the
interstices. The more you practise this, when the subject evidently
calls for it, the more your eye will enjoy the higher qualities of
colour. The process is, in fact, the carrying out of the principle of
separate colours to the utmost possible refinement; using atoms of
colour in juxtaposition, instead of large spaces. And note, in filling
up minute interstices of this kind, that if you want the colour 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 colour 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.

(_b._) If a colour is to be darkened by superimposed portions of
another, it is, in many cases, better to lay the uppermost colour 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 colours 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 got i