PICTURE. 
392 
for this purpofe, are—gum-arabic diflblved in water, 
with the addition of fugar or fugar-candy, to prevent its 
cracking; glair, or whites of eggs, mixed with a little 
brandy or fpirit of wine in order to make it work more 
freely, and a lump of fugar to‘ prevent its cracking; 
ifinglafs-fize, nfed as either of the former, or mixed with 
a fourth or fifth of its weight of honey or fugar; and 
varniflies formed of gum-refins diflblved in fpirit of wine, 
or oil of turpentine, which laft are called uil-varnijlies. 
Paintings in miniature are preferved by plates of glafs, 
or the talc called ifinglafs, placed before them in the 
frame. Paintings in diffempermay be rendered more du¬ 
rable, and preferved from foulnefs, by varnifhing them 
with hot fize, boiled to a ftrong confidence, in which a 
fifteenth or twentieth part of honey has been diflblved. 
Crayons muft be preferved in the fame manner with paint¬ 
ings in water-colours, by plates of glafs or ifinglafs. 
When pictures are cut or torn, they may be repaired by 
laying them on an even board or table, carefully putting 
together the torn or divided parts with colour laid as a 
cement in and over the joint, and keeping them in the 
fituation till the cement is thoroughly dried. The pro¬ 
tuberance of the cement may be eaiiiy reduced with a 
penknife, and the repaired part properly coloured fo as to 
correfpond with the pifture. When part of the cloth is 
deftroyed, a piece of canvafs fomewhat bigger than the 
vacant fpace is to be plaftered over on the outfide of the 
cloth with white or any other colour ; and, when it is 
thoroughly dry, the inequality of the pifture in this part 
is to be filled up with the fame matter, and properly re¬ 
duced and coloured. 
The art of cleaning pidures and paintings is of great 
confequence in order to their prefervation : in this ope¬ 
ration great (kill and care are requiiite, fo that the men- 
ftruum ufed for taking off any foulnefs may not difiolve 
the oil in the painting itfelf, or diforder its colours; and 
that each fort of varnifli with which the painting is co¬ 
loured may be taken off without injury to the painting. 
The firlt and moll general fubftance ufed for cleaning pic¬ 
tures is water, which will remove foulnefs arifing from 
many kinds of glutinous bodies, as fugar, honey, glue, 
&c. and any varnifli of gum-arabic, glair of eggs, or ifin¬ 
glafs, without affeding the oil that holds the colours to¬ 
gether. Olive-oil or butter will diflblve pitch, refin, and 
other fubftances of a like kind, without injuring the oil 
of the painting. Pearl-aflies, diflblved in water, form a 
proper menftruum for mod kinds of matter that foul 
paintings; but they mull be very cautioufly ufed, as they 
will corrode the oil of the painting, if there be no varnifli 
of the gum-refins over it. Soap is of the fame nature, and 
fhould be cautioufly applied, and only to particular fpots 
that elude all other methods. Spirit of wine will diflblve 
all the gums and gum-refins, except gum-arabic, and is 
therefore very neceffary for taking off from pidures var- 
nifhes compofed of fuch fubftances ; but it alfo corrodes 
the oil of the painting. This Is alfo the cafe with oil of 
turpentine, and e(fence of lemon, fpirit of lavender and 
rofemary, and other eflential oils. With regard to paint¬ 
ings that are varnilhed with gum-arabic, glair of eggs, or 
ifinglafs, the varnifh fliould be taken off when they are 
to be cleaned. This may be eafily diftinguifhed by wet¬ 
ting any part of the painting, which will feel clammy if 
varnilhed with any fubftance foluble in water. This kind 
of varnifli maybe taken off with hot water and a fponge, 
cr by gentle rubbing with a linen cloth dipped in warm 
water. If paintings, on this trial, appear to be varnilhed 
with gum-refins, or fuch fubftances as cannot be diflblved 
in water, they may, in fome cafes, be fiifficiently cleaned 
by a fpunge with warm water; and any remaining foul¬ 
nefs may be removed by rubbing the painting over with 
olive-oil made warm, or with butter, which fhould be 
wiped off with a woollen cloth 5 and, if the picture re¬ 
quire further cleaning, wood-afbes or pearl-aflies may be 
ufed in the following manner: Take an ounce of pearl- 
aflies, and diflblve them in a pint of water; or take two 
4 
pounds of wood-afhes, and ftir them well in three quarts 
of water, once or twice in an hour for half a day 5 then 
pour off the clear fluid, and evaporate it to a quart or 
three pints; wafh the painting well with a fponge dipped 
in either of thefe leys, and rub gently any foul fpots with 
a linen cloth till they difappear. If this method fail, re- 
courfe muff be had, firlt to fpirit of wine, then to oil of 
turpentine, and, if thefe are ineffectual, the offence of 
lemons ; with either of which the foul fpots (liould be 
(lightly moiftened, and the part immediately rubbed 
gently with a linen cloth. After a little rubbing, if oil 
of turpentine or effence of lemon has been applied, olive- 
oil fhould be put upon the fpot; and water, if fpirit of 
wine has been ufed; which fliould be taken off with a 
woollen cloth; repeating the operation till the foulnefs 
be removed. When paintings appear to have been var¬ 
nilhed with thofe fubftances that will not diffolve in wa¬ 
ter, and after the ufe of the above means retain their 
foulnefs, the following- method will fucceed : Place the 
pifture or painting in a horizontal fituation; and moiften, 
or rather flood, by means of a fponge, the furface with 
very ftrong rectified fpirit of wine: keep the painting 
thus moiftened, by adding frelh quantities of the fpirit, 
for fome minutes; then flood the whole furface copi- 
oufly with cold water ; wafh off the whole without rub¬ 
bing ; and, when the painting is dry, repeat the operation 
till the whole varnifli is taken off. Handmaid to the Arts, 
vol. i. 
The art of removing paintings in oil from the cloth or 
wood on which they are originally done, and transfer¬ 
ring them to new grounds of either kinds of fubftance, 
is of great ufe. For thofe on cloth or canvafs, the me¬ 
thod is as follows: Let the decayed pifture be cleanfed 
of all greafe that may be on its furface, by rubbing it 
very gently with crumb of ftale bread, and then wiping 
it with a very fine foft linen cloth. It muft then be laid, 
with the face downwards, on a fmooth table covered with 
fan-paper, or India-paper; and the cloth on the reverfe 
muft be well foaked with boiling water, fpread upon it 
with a fponge, till it appears perfectly foft and pliable. 
Turn the pifture with the face upwards; and, having 
ftretched it evenly on the table, pin it down with nails at 
the edges. Having melted a quantity of glue, and 
drained it through a flannel cloth, fpread part of it, when 
a little ftiffened, on a linen cloth of the fize of the paint¬ 
ing; and, when this is fet and dry, lay another coat over 
it ; when this becomes ft iff, fpread fome of the glue, mo¬ 
derately heated, over the face of the pi ft u re, and lay 
over it the linen cloth already prepared in the moll even 
manner, and nail it down to the pifture and table. 
Then expofe the whole apparatus to the heat of the fun, 
in a place where it may be fecure from rain, till the glue 
be perfectly dry and hard ; when this is the cafe, remove 
the picture and linen cloth from the table; turn the 
pifture with the face downwards, and let it be ftretched 
and nailed to the table as before; then raife round its 
edge a border of wax, as in the etching of copper plates, 
forming a kind of {hallow trough with the furface of the 
pifture; into which pour a proper corroding fluid, as 
oil of vitriol, aqua fortis, or fpirit of fait, but the laft is to 
be preferred : dilute either of thefe with water to fuch a 
degree, determined by previous trials, that they may 
deftroy the threads of the original canvafs or cloth of 
the pifture, without difcolouring it. When the corroding 
fluid has anfwered this purpofe, drain it oft’ through a 
pafl'age made at one end of fhe border of wax, and walk 
away the remaining part by repeatedly pouring quanti¬ 
ties of frelh water on the cloth. The threads of the 
cloth muft then be carefully picked out till the whole 
be taken away. The reverfe furface of the painting, 
being thus wholly freed from the old cloth, muft be well' 
walhed with water by means of a fponge, and left to dry. 
In the mean time prepare a new piece of canvafs ot the 
fize of the painting; and, having fpread fome hot glue, 
purified as before, and melted with a little brandy or 
