en you have got the whole well into shape, proceed to lay on the
stains and spots with great care, quite as much as you gave to the
forms. Very often, spots or bars of local colour do more to express form
than even the light and shade, and they are always interesting as the
means by which Nature carries light into her shadows, and shade into her
lights, an art of which we shall have more to say hereafter, in speaking
of composition. Fig. 5. is a rough sketch of a fossil sea-urchin, in
which the projections of the shell are of black flint, coming through a
chalky surface. These projections form dark spots in the light; and
their sides, rising out of the shadow, form smaller whitish spots in the
dark. You may take such scattered lights as these out with the penknife,
provided you are just as careful to place them rightly, as if you got
them by a more laborious process.

When you have once got the feeling of the way in which gradation
expresses roundness and projection, you may try your strength on
anything natural or artificial that happens to take your fancy, provided
it be not too complicated in form. I have asked you to draw a stone
first, because any irregularities and failures in your shading will be
less offensive to you, as being partly characteristic of the rough stone
surface, than they would be in a more delicate subject; and you may as
well go on drawing rounded stones of different shapes for a little
while, till you find you can really shade delicately. You may then take
up folds of thick white drapery, a napkin or towel thrown carelessly on
the table is as good as anything, and try to express them in the same
way; only now you will find that your shades must be wrought with
perfect unity and tenderness, or you will lose the flow of the folds.
Always remember that a little bit perfected is worth more than many
scrawls; whenever you feel yourself inclined to scrawl, give up work
resolutely, and do not go back to it till next day. Of course your towel
or napkin must be put on something that may be locked up, so that its
folds shall not be disturbed till you have finished. If you find that
the folds will not look right, get a photograph of a piece of drapery
(there are plenty now to be bought, taken from the sculpture of the
cathedrals of Rheims, Amiens, and Chartres, which will at once educate
your hand and your taste), and copy some piece of that; you will then
ascertain what it is that is wanting in your studie