MISCELLANEOUS ESSAYS. 385
new piece of canvas muft be cut of the fize of the painting, which row remains cemented to the linen cloth put on the face of it; and the reverfe of the painting being dry, and fpread over by fome hot glew, purified as before, and melted with a little brandy, or fpirit of wine, the new canvas muft be laid on it, in the molt even manner, while the glew yet remains hot, and fettled to it by compreffion : which may be per- formed by thick plates of lead, or flat pieces of polifhed marble. Great care fliould however be taken in the laying them on to prevent the edge from cutting or bruifing the paint ; as alfo during the fet- ting of the glew :o take them off; and wipe them at proper in- terval?, to prevent their adhering to the cloth by means of the glew, \Thich may be preiTed through it. The lead or marble, by which the compreffure is made, being removed when the glew is fet, the cloth muft be kept in the fame ftate, till the gle^v be per- fedlly dry and hard. Then the whole muft be again turned with the other fide upwards, and the border of wax being replaced, the linen cloth on the face of the painting muft be deftroyed by means of the corroding fiuid, in ihe fame manner as the canvas was before: but greater care muft bz taken with refpedl to the ftrength of the corroding matter, and in the picking out the threads of the cloth ; becaufe the face of the painting is defended only by the coat of glew which cemented the linen cloth to it. The painting muft then be free from the glew, by wafhing it with ho; \va:er. Vol. I.
fpread and rubbed on the furface by a fponge; which (hould be cleanfed frequently during the ope- ration, by clipping and Iqueezing i: in clean warer. The painting may afterwards be varnifhed as a new picture; and if the opera- tion is well conduced, it will be transferred to the new cloch in a perfect ftate.
When the painting is original- ly on vv'cod, it muft be firft de- tached from the ceiling or wain- fcot where it was fixed ; and the furface of it covered with a linea cloth, ceaiented to it by means of glew, in the manner before di- reeled for the paintings on canvas. A proper table being then pro- vided, and overfpread with a blanket, or thinner woollen cloth, if laid feveral doubles, the paint- ing muft be laid upon it with the face downwards, and fixed fleady; and the boards or wood on which it was done maft be planed away, till the (hell remaia as thin as it can be made, without damaging the paint under it. The proceedings muft afterwards be the fame as was before pracViied in the cafe of the paintings on can- vas, till that on the wood be in like manner transferred to acloth or canvas.
The whole of the above ope- ration muft be managed with the greateft care, otherwil'e the paint- ing will receive fome damage ; and fo much nicety is required in the corrofion, and taking ofF the threads of the cloth, that it can fcarcely be performed right- ly, buc by fuch as have had iome experience in the matter. It is proper, therefore, for any perfon who would praclife it in the cafe
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