rk on the white paper. Now a stupid painter
would represent, for instance, a drinking-glass beside the hand of one
of his figures, and because he had been taught by rule that "shadow was
darker than the dark side," he would never think of the reflection from
the glass, but paint a dark grey under the hand, just as if no glass
were there. But a great painter would be sure to think of the true
effect, and paint it; and then comes the stupid critic, and wonders why
the hand is so light on its dark side.

Thus it is always dangerous to assert anything as a _rule_ in matters of
art; yet it is useful for you to remember that, in a general way, a
shadow is darker than the dark side of the thing that casts it,
supposing the colours otherwise the same; that is to say, when a white
object casts a shadow on a white surface, or a dark object on a dark
surface: the rule will not hold if the colours are different, the shadow
of a black object on a white surface being, of course, not so dark,
usually, as the black thing casting it. The only way to ascertain the
ultimate truth in such matters is to _look_ for it; but, in the
meantime, you will be helped by noticing that the cracks in the stone
are little ravines, on one side of which the light strikes sharply,
while the other is in shade. This dark side usually casts a little
darker shadow at the bottom of the crack; and the general tone of the
stone surface is not so bright as the light bank of the ravine. And,
therefore, if you get the surface of the object of a uniform tint, more
or less indicative of shade, and then scratch out a white spot or streak
in it of any shape; by putting a dark touch beside this white one, you
may turn it, as you choose, into either a ridge or an incision, into
either a boss or a cavity. If you put the dark touch on the side of it
nearest the sun, or rather, nearest the place that the light comes from,
you will make it a cut or cavity; if you put it on the opposite side,
you will make it a ridge or mound: and the complete success of the
effect depends less on depth of shade than on the rightness of the
drawing; that is to say, on the evident correspondence of the form of
the shadow with the form that casts it. In drawing rocks, or wood, or
anything irregularly shaped, you will gain far more by a little patience
in following the forms carefully, though with slight touches, than by
laboured finishing of textures of surface and transparencies of shadow.

Wh