GILDING. 273 



aperture must not be opened till the fluids have 

 compleely separated themselves from each other. 

 It is then to be opened ; by which means the 

 liquid which has taken the lowest place by its 

 greater gravity, viz. the nitro-muriatic acid will 

 run oiF; after which, the aperture is to be shut, 

 and tha funnel will then be found to contain 

 nothing but ether mixed with the gold, which is 

 to be put into well-closed bottles, and preserved 

 for use. In order to gild iron or steel, the metal 

 must first be well polished with the finest emery, 

 or rather with the finest crocus martis, or colcothar 

 of vitriol, and common brandy. The auriferous 

 ether is then to be applied with a small brush ; the 

 ether soon evaporates, and the gold remains on the 

 surface of the metal. The metal may then be put 

 into the fire, smd afterwards polished. By means 

 of this auriferous ether, all kinds of figures may 

 be delineated on iron, by employing a pen, or fine 

 brush. It is in this manner, probably, that the 

 Sohlinger sabre blades are gilded. 



Instead of ether, the essential oils may be used ; 

 such as oil of turpentine, or oil of lavender, which 

 will also take gold from its solution. 



Cold Gilding of Silver. Eissolve gold in the 

 nitro-muriatic acid, and dip some linen rags in the 

 solution ; then burn them, and carefully preserve 

 the ashes, which will be very black, and heavier 

 than common. When any thing is to be gilded, it 

 must be previously well burnished ; a piece of 

 cork is then to be dipped, first into a solution of 

 salt in water, and afterwards into the black powder ; 

 and the piece, after being rubbed with it, must be 

 burnished. This powder is frequently used for 

 gilding delicate articles of silver. 



VOL. n. T 



