143 MemorajidumSy Hints f Ptrcepfs, and Recipes, &c. 



mon. Eub thefe aflies on the furface of the filver either with 

 the fingers or a piece of leather or of cork, by which means 

 the fine particles of gold thev contain will be left on the fur- 

 face of the metal. If the filrer be then wafhed, fo as to re- 

 move the remaining part of the afhes, the filver will have 

 Icarcely anv appearance of gilding; but on being burnilhed 

 it will afTunie a beautiful gold colour. This method of gilding 

 is very eafy, and requires very little gold. 



GilJuig of Urufs. 



Fine inftrunicnts of brafs, iri order that their furface may 

 be kept longer clean, may be gilded in the following manner: 



Provide a faturatcd folutioivof gold, and, having evaporated 

 it to the confifttnce of oil, lufler it to flioot into cryftals. 

 Thefe cryftals mud: then be dilfolvcd in pure water, and 

 the articles lo be gikled being immerfed in it are then to- 

 be wallied in pnre water, and afterwards burniflied. This 

 pi-ocefs may be repeated feveral limes till the articles have 

 been well gih. A folution of gold cryftals is preferred to a 

 mere folution of gold, becaufe in the latter there is always 

 a portion of free acid, which will not fail to exercife more o? 

 lei's aiition on the furfi^ce of the brafs oc copper, and injure 

 its polifh. 



Lacieriug of Brjfs^ 



Various articles made of brafs have fometimes an appear- 

 ance as if they were gilded. This appearance, however, is 

 produced by means- of a folution of gum-l«ic in fpirit of 

 wine, with which, they arc rubbed over. As long as the 

 lac lafts, they retain their fplendour. Thefe articles, how-^ 

 ever, are attended with this inconvenience, that they mufi 

 ni-'ver be cleaned with a ftrong brufh, or fcourcd with chalk 

 and the like, but only be wiped with a foft ragj for as ibon 

 as the lac is rublx-d off they lofe their brilliancy. A varnifh 

 of this kind may be prepared in the following manner : 



Dilfolve two ounces of very pure and fine guni-lac int 

 48 ounces of alcoliol, sis^ii place the folution in a fxnd-bath 

 expofed to a moderate lieat. To prevent the too al)UuJant 

 evaporation of the fpirit of wine, as well as the burlting of 

 the glafs, a piece of bladder ought to be bound over the 

 latter, and a few holes made in it vvith a nc edle. In another 

 glafs difloKe, in the fame quantity of fpirit of wine, n\\ ounce 

 of dragon's blood in grains. When both the iolut'ons are 

 completed, mix them together; then put three grains of yel- 

 low wood into it, and firffer it to remain there twelve hours 

 in a moderate heat: after v\hich llraia the liquor through 



filtering 



