forcibly. Secondly, light reflected from its lustrous surface, sometimes
the blue of the sky, sometimes the white of clouds, or the sun itself
flashing like a star. Thirdly, forms and shadows of other leaves, seen
as darkness _through_ the translucent parts of the leaf; a most
important element of foliage effect, but wholly neglected by landscape
artists in general.

The consequence of all this is, that except now and then by chance, the
form of a complete leaf is never seen; but a marvellous and quaint
confusion, very definite, indeed, in its evidence of direction of
growth, and unity of action, but wholly indefinable and inextricable,
part by part, by any amount of patience. You cannot possibly work it out
in fac simile, though you took a twelvemonth's time to a tree; and you
must therefore try to discover some mode of execution which will more or
less imitate, by its own variety and mystery, the variety and mystery of
Nature, without absolute delineation of detail.

Now I have led you to this conclusion by observation of tree form only,
because in that the thing to be proved is clearest. But no natural
object exists which does not involve in some part or parts of it this
inimitableness, this mystery of quantity, which needs peculiarity of
handling and trick of touch to express it completely. If leaves are
intricate, so is moss, so is foam, so is rock cleavage, so are fur and
hair, and texture of drapery, and of clouds. And although methods and
dexterities of handling are wholly useless if you have not gained first
the thorough knowledge of the form of the thing; so that if you cannot
draw a branch perfectly, then much less a tree; and if not a wreath of
mist perfectly, much less a flock of clouds; and if not a single grass
blade perfectly, much less a grass bank; yet having once got this power
over decisive form, you may safely--and must, in order to perfection of
work--carry out your knowledge by every aid of method and dexterity of
hand.

But, in order to find out what method can do, you must now look at Art
as well as at Nature, and see what means painters and engravers have
actually employed for the expression of these subtleties. Whereupon
arises the question, what opportunity have you to obtain engravings? You
ought, if it is at all in your power, to possess yourself of a certain
number of good examples of Turner's engraved works: if this be not in
your power, you must just make the best use you can of the s