GILDING. 
should be perfectly pure, as the least por- 
tion of lead or bismuth would very mate- 
rially injure the beauty of the gilding, by de- 
teriorating the colour of the gold, and 
filling it with black specks ; on this ac- 
count no mercury ought to be employed 
that has not been procured by distillation 
from the red precipitate (nitrous red oxide 
of mercury) either alone or mixed with a 
little charcoal powder. 
Gold is prepared in three different ways. 
The first and simplest is to put into a glass 
or earthern mortar some gold-leaf, with a 
little honey or thick gum-water, and grind 
the mixture for a considerable time, till the 
gold is reduced to extremely minute frag- 
ments ; when this is done, a little warm 
water will wash out the honey or gum, 
leaving the gold behind in a flaky pulveru- 
lent state. A less tedious and more effec- 
tual way of comminuting the gold, is to dis- 
solve it in nitro-muriate acid, and then pre- 
cipitate it' with a piece of copper : the pre- 
cipitate, after being digested in distilled 
vinegar, and then washed in water and 
dried, is in the form of a very fine powder, 
and both works better, and is easier to 
burnish than the ground leaf-gold. The 
finest ground gold is however produced by 
heating very gradually the gold-amalgam in 
an open earthern vessel, and continuing the 
fire till the whole of the mercury is evapo- 
rated, taking care that the amalgam shall be 
constantly stirred with apiece of glass, rod, 
or tobacco-pipe, in order to prevent the 
particles of gold from adhering as the mer- 
cury flies off. When the mercury is com- 
pletely evaporated, the residual gold being 
then ground in a Wedgewood-ware mortar, 
with a little water, and afterwards dried, it 
is fit for use. ' 
Gilding is performed either with or with- 
out heat. By the first of these methods 
those substances are gilt which are not lia- 
ble to alteration by exposure to a moderate 
heat, such as metals, and sometimes glass 
and porcelain -. the second method is prac- 
tised with those substances, such as wood, 
paper, lead, silk, lacquered and japanned 
ware, &c. which would be injured and even 
destroyed at the temperature requisite for 
gilding the former. The last of these methods 
being the simplest, shall be first described, 
and we shall begin with the art of gilding 
on wood. 
There are two methods for gilding on 
wood, namely, oil gilding and burnished 
gilding. Oil gilding is thus performed : the 
wood must first be covered, or primed, with 
two or three coatings of boiled linseed oi! 
and white-lead, in order to fill up the pores 
and to conceal the irregularities of the sur- 
face, occasioned by the veins in the wood. 
When the priming is quite dry, a thin coat 
of gold-size must be laid on. Thi is pre- 
pared by grinding together some strongly 
calcined red ochre with the thickest drying 
oil that can be procured, and the older the 
better: that it may work freely, it is to be 
mixed previously to being used with a little 
oil of turpentine, till it is brought to a pro- 
per consistence. If the gold-size is good, it 
will be sufficiently dry in twelve hours, 
more or less, to allow the artist to proceed 
to the last part of the process, which is the 
application of the gold. For this purpose a 
leaf of gold is spread on the cushion (formed 
by a few folds of flannel secured on a piece 
of wood, about eight inches square, by a tight 
covering of leather), and is cut into strips of 
a proper size by a blunt pallet-knife ; each 
strip being then taken up on the point of a 
fine brush, is applied to the part intended 
to be gilded, and is then gently pressed 
down by a ball of soft cotton ; the gold im- 
mediately adheres to the sticky surface of 
the size, and after a few minutes the dex- 
terous application of a large camels’ hair 
brush sweeps away the loose particles of the 
gold leaf without disturbing the rest. In a 
day or two the size will be completely 
dried, and the operation is finished. The 
advantages of this method of gilding are, 
that it is very simple, very durable, not 
readily injured by changes of weather, even 
when exposed to the open air, and when 
soiled it may be cleaned by a little warm 
water and a soft brush: its disadvantage is, 
that it cannot be burnished, and therefore 
wants the high lustre produced by the next 
method. Its chief employment is in out- 
door work. 
Burnjshed gilding, or gilding in distemper, 
is thus performed. The surface to be gilt 
must be carefully covered with strong size, 
made by boiling down two pieces of white- 
leather, or clippings of parchment, till they 
are reduced to a stiff jelly; this coating 
being dried, eight or ten more must be ap- 
plied, consisting of the same size, mixed 
with fine Paris-plaster or washed chalk; 
when a sufficient number of layers have 
been put on, varying according to the na- 
ture of the work, and the whole is become 
quite dry, a moderately thick layer must- 
be applied, composed of size and bole, or 
yellow ochre: while this last is yet moist, 
the gold leaf is to be put on in the usual 
