=--The manner of execution to
be selected must conform to the nature of the objects. This is
essential, as we have at our disposition only a point, the play of which
on the varnish is always the same. It follows that we must vary its
strokes, so as to make it express difference in texture. If we examine
the etchings of the old masters, we shall find that they had a special
way of expressing foliage, earth, rocks, water, the sky, figures,
architecture, &c., without, however, making themselves the slaves of too
constraining a tradition.

6. =The Work of the Acid.=--After the subject has been drawn on the
ground, the acid steps in to give variety to the forms which were laid
out for it by the needle, to impart vibration to this work of uniform
aspect, and to inform it with the all-pervading warmth of life. In
principle, a single biting ought to be sufficient; but if the artist
desires to secure greater variety in the result by a succession of
partial bitings, the different distances may be made to detach
themselves from one another by covering up with varnish the parts
sufficiently bitten each time the plate is withdrawn from the bath. The
different parts which the mordant is to play must be regulated by the
feeling: discreet and prudent, it will impart delicacy to the tender
values; controlled in its subtle functions, it will carefully mark the
relative tones of the various distances; less restrained and used more
incisively, it will dig into the accentuated parts and will give them
force.

7. =The Use of the Dry Point.=--If harmony has not been sufficiently
attained, the _dry point_ is used on the bare metal, to modify the
values incompletely rendered, or expressed too harshly. Its office is to
cover such insufficient passages with a delicate tint, and to serve, as
Charles Blanc has very well expressed it, as a _glaze_ in engraving.

8. =Spirit in which the Etcher must work.=--Follow your feeling, combine
your modes of expression, establish points of comparison, and adopt from
among the practical means at command (which depend on the effect, and on
which the effect depends) those which will best render the effect
desired: this is the course to be followed by the etcher. There is
plenty of the instinctive which practice will develop in him, and in
this he will find a growing charm and an irresistible attraction. What
happy effects, what surprises, what unforeseen discoveries, when the
varnish is removed from the plate!