C38 GILDING 



9. Ungraining ; consists in rubbing the whole work with shave-grass, to remove any 

 granular appearance. 



10. Coat of assiette ; trencher coat. This is the composition on which the gold is 

 to be laid. It is composed of Armenian bole, 1 pound ; hematite, 2 ounces ; and 

 as much galena ; each separately ground in water. The whole are then mixed 

 together, and ground up with about a spoonful of olive oil. The assiette well made 

 and applied gives beauty to the gilding. The assiette is tempered with a white sheep j 

 skin glue, very clear and well strained. This mixture is heated, and applied in thrcd 

 successive coats witli a very fine long-haired brush. 



11. Rubbing, with a piece of dry, linen cloth ; except the parts which are be bur- 

 nished, which are to receive other two coats of assiette tempered with glue. 



12. Gilding. The surface being damped with cold water (iced in summer) has 

 then the gold-leaf applied to it. The hollow grounds must always be gilded before 

 the prominent parts. Water is dexterously applied by a soft brush, immediately 

 behind the gold-leaf, before laying it down, which makes it lie smoother. Any 

 excess of water is then removed with a dry brush. 



13. Burnishing, with bloodstone. 



14. Deadening. This consists in passing a thin coat of glue, slightly warmed, over 

 the parts that are not to be burnished. 



15. Mending ; that is, moistening any broken points with a brush, and applying 

 bits of gold-leaf to them. 



16. The vermeil coat. Vermeil is a liquid which gives lustre and fire to the gold : 

 and makes it resemble or-inoulu. It is composed as follows : 2 ounces of annotto, 1 

 ounce of gamboge, 1 ounce of vermilion, half an ounce of dragon's blood, 2 ounces of 

 salt of tartar, and 18 grains of saffron, are boiled in a litre (2 pints English) of wat cr, 

 over a slow fire, till the liquid be reduced to a fourth. The whole is then passed 

 through a silk or muslin sieve. A little of this is made to glide lightly over the gold, 

 with a very soft brush. 



17. Repassage; is passing over the dead surfaces a second coat of deadening 

 glue, which must be hotter than the first. This finishes the work, and gives it strength. 



Leaf gilding, on paper or vellum, is done by giving them a coat of gum-water or 

 fine size, applying the gold-leaf ere the surfaces be hard dry, and burnishing with agate. 



Gold lettering, on bound books, is given without size, by laying the gold-leaf on the 1 

 leather, and imprinting it with hot brass types. 



The edges of the leaves of books are gilded, while they are in the press where they 

 have been cut smooth, by applying a solution of isinglass in spirits, and laying on the 

 gold when the edges are in a proper state of dryness. The French workmen employ 

 a ground of Armenian bole, mixed with powdered sugar-candy, by means of white-of- 

 egg. This ground is laid very thin \ipon the edges, after fine size or gum-water lias 

 been applied ; and when the ground is dry it is rubbed smooth with a wet rag, which 

 moistens it sufficiently to take the gold. 



Japanners' gilding is done by sprinkling or daubing with wash-leather, some gold- 

 powder over an oil sized surface, mixed with oil of turpentine. This gives the appear- 

 ance of frosted gold. The gold-powder may be obtained, either by precipitating gold 

 from its solution in aqua regia by a solution of pure sulphate of iron, or by evaporating 

 away the mercury from some gold-amalgam. 



II. CHEMICAL GILDING, or the application of gold by chemical affinity to metallic 

 surfaces. 



A compound of copper with one-seventh of brass is the best metal for gilding on ; 

 copper by itself being too soft and dark coloured. Ordinary brass, however, answers 

 very well. We shall describe the process of wash gilding, with M. D'Arcot's im- 

 provements, now generally adopted in Paris. 



Wash gilding consists in applying evenly an amalgam of gold to the surface of a 

 copper alloy, and dissipating the mercury with heat, so as to leave the gold film fixed. 

 The surface is afterwards burnished or deadened at pleasure. The gold ought to bd 

 quite pure, and laminated to facilitate its combination with the mercury; which 

 should also be pure. 



Preparation of the amalgam. After weighing the fine gold, the workman puts it in 

 a crucible, and as soon as this becomes faintly red, he pours in the requisite quantity 

 of mercury ; which is about 8 to 1 of gold. He stirs up the mixture with an iron rod, 

 bent hookwise at the end, leaving the crucible on the fire till he perceives that nil tho 

 gold is dissolved. He then pours tho amalgam into a small earthen dish containing 

 water, washes it with care, and squeezes out of it with his fingers all tho running 

 mercury that he can. Tho amalgam that now remains on the sloping sides of the 

 vessel is so pasty as to preserve the impression of the fingers. When this is sq 1 

 in a chamois-leather bag, it gives up much mercury ; and remains an amalgam, con- 

 sisting of about 33 of mercury, and 57 of gold, in 100 parts. The mercury which 



