ENG 
or sugar, and fine washed whiting, exactly 
of the consistence of Indian ink, and laid 
on the granulated surface with a pencil, in 
the same free manner adopted on paper ; 
after the above composition is thoroughly 
dry, the whole plate must be covered with 
a thin, weak, varnish of mastich, turpentine, 
or asplialtum, and when dried a second time, 
the aqua fortis is to be applied, which im- 
mediately breaking the varnish and whiting, 
will corrode the plate precisely in the marks 
of the pencil. The border of wax may be 
removed by heating the plate gently, and 
the ground varnish, &c. by oil of turpentine ; 
a little fine whiting and a clean rag will then 
render the plate fit for the printer. 
As the manner of procuring the grain by 
heating the powdered substance scattered 
over the plate is liable to objections, on ac- 
count of the difficulty of making the par- 
ticles assume the desired coarseness, or the 
reverse, and the engraving so produced ra- 
pidly wearing out in the printing, another 
has been contrived far more certain and 
satisfactory. In this mode, common resin, 
ntastich, or Burgundy pitch, is dissolved in 
highly rectified spirits of wine of the best 
quality, each of which produce different 
descriptions of grains; but these substances 
may be mixed in such proportions as the 
artist prefers, and he must recollect that the 
resin makes the coarsest: to satisfy him- 
self in this particular, the grain of every 
proportion should be tried on useless pieces 
of copper. Having a solution to his mind, 
it must remain undisturbed till every im- 
pure particle has subsided. The plate, po- 
lished and cleansed with whiting, is then 
placed to receive the liquid, which being 
poured on it, is held slanting till the most 
fluid parts has run off; it is afterwards laid 
to dry, in the progress of which the resin 
granulates, and adheres firmly to the sur- 
face. The greatest precaution must be 
used in going through this process, as the 
interposition of dust, grease, hairs, or fibres 
of linen, will cause total derangement, and 
even then it is subject to most vexatious 
uncertainty, often compelling the experi- 
eneed artist to renew it to obtain a good 
grain ; in short, the weather and untoward 
accidents frequently ruin his labours, though 
guarded against by every method his inven- 
tion suggests. There is one advantage at- 
tending the pouring the liquid off, which is, 
that the heaviest particles of the resin will 
float to the lower side, and consequently 
leave a coarser grain there than above, 
much better suited to the deep shades of a 
ENN 
landscape than if the granulations had been 
equally fine ; in large subjects the grain is 
sometimes laid coarse purposely in the parts 
requiring it. 
Although a fine grain lias a very pleasing 
effect, and will bear close examination, it 
has several disadvantages ; for this reason a 
medium description of granulation is pre- 
ferable, which admitting the aqua fortis 
freely to the copper, it bites deeper, and is 
less apt by acting laterally to force off the 
resin, besides, the plate will of course afford 
a greater number of impressions. 
Some hints have been given already for 
biting the plate ; but however useful those 
may be found in particular instances, there 
are others which can only be extracted from 
close application and experiment, and those 
are often varied in their results : as an illus- 
tration, we may suppose an artist provided 
with several pieces of copper granulated, 
and trying each successively by his watch 
with spirits of nitre diluted to the state of 
the air at the commencement of his opera- 
tions, how many minutes is necessary to 
produce one tint, how many for a second, 
&c. granting him two hours for his experi- 
ment ; during this interval a violent shower 
of rain may occur, which will immediately 
affect the acid by weakening its properties 
in the. same proportion as salt is observed to 
be dissolved by a humid atmosphere : thus 
it appears, a result obtained on a clear dry 
day will not suit a rainy one, and vice versa. 
In opposition to this discouraging uncer- 
tainty, and in opposition to the judgment and 
preference of all true connoisseurs, aqua- 
tinted prints seem to increase in value in 
the estimation of many persons, who forget 
that national taste should be improved by 
works of superior execution, and not vitiat- 
ed by being constantly familiarized to those 
produced by means which set genius at de- 
fiance. 
ENNEAGON, in geometry, a polygon 
with nine sides. If each side be 1, the area 
will be 6, 18, &c. 
ENNEANDMA, the name of the ninth 
class in Linnaeus's sexual system, consist- 
ing of plants which have hermaphrodite 
flowers, with nine stamina or male organs. 
The orders, or secondary divisions, in this 
class are three, being founded on the num- 
ber of the styles, seed buds, or female or- 
gans. Lauras, tinus, and cassytha, have 
one style ; rhubarb (rheum), has a triple 
stigma or summit, but scarce any style; 
flowering rush has six styles. The genera 
just enumerated are all that belong to the 
