GOLD. 



to foui* carats, after which the additions 

 may proceed by whole carats. Other 

 needles may be made in the same man- 

 ner, with copper instead of silver ; and 

 other sets may have the addition, consist- 

 ing either of equal parts of silver and 

 copper, or such proportions as the occa- 

 sions of business require. 



In foreign countries, where trinkets 

 and small works are required to be sub- 

 mitted to the assay of the touch, a variety 

 of needles are necessary ; but they are 

 not much used in England. They afford, 

 however, a degree of information, which 

 is more considerable than might at first 

 be expected. The attentive assayer not 

 only compares the colour of the stroke 

 made upon the touchstone by the metal 

 under examination with that produced by 

 his needle, but will likewise attend to the 

 sensation of roughness, dryness, smooth- 

 ness, or greasiness, which the texture of 

 the rubbed metal excites when abraded 

 by the stone: When two strokes, per- 

 fectly alike in colour, are made upon the 

 stone, he may then wet them with aqua- 

 fortis, which will affect them very differ* 

 ently if they be not similar compositions; 

 or the stone itself may be made red hot 

 by the fire, or by the blowpipe, if thin 

 black pottery be used, in which case 

 the phenomena of oxydation will differ 

 according to the nature and quantity of 

 the alloy. 



Gold ores may be assayed in the moist 

 way by pounding them very fine, weigh- 

 ing a determinate portion, and attempting 

 their solution in nitric acid, which will dis- 

 solve the matrix if it consist of calcareous 

 earth ; or if it be sulphate of lime, the 

 powder may be digested in aqua-regia as 

 long as any metallic substance is taken 

 up ; after which the gold may be precipi- 

 tated by an addition of sulphate of iron, 

 which will cause it to fall down in the 

 metallic state. 



The principal use of gold is as the me- 

 dium of exchange in coin, for which it has 

 been chosen to occupy the first place, on 

 account of its scarcity, its great weight, 

 and its not being subject to tarnish. The 

 gold coins of Great Britain contain eleven 

 parts of gold and one of copper. See COIJT. 



Gold is likewise used in gilding. See 

 GILDING. 



The .other uses of gold, in laces, &c. 

 are sufficiently known. 



GOLD beating. See GOLD. 



GOLD wire, a cylindrical ingot of silver, 

 superficially gilt, or covered with gold at 

 the fire, and afterwards drawn successive- 

 ly through a great number of little round 



holes of a wire-drawing iron, each less 

 than the other, till it be sometimes no big- 

 ger than a hair of the head. It may be 

 observed, that before the wire be reduced 

 to this excessive fineness, it is drawn 

 through above an hundred and forty dif- 

 ferent holes, and that each time they draw 

 it, it is rubbed afresh over with new wax, 

 both to facilitate its passage, and to pre- 

 vent the silver's appearing through it. 



GOLD -wire flatted, is the former wire 

 flatted between two rollers of polished 

 steel, to fit it to be spun on a stick, or to 

 be used flat, as it is, without spinning, in 

 certain stuffs, laces, embroideries, &c. 



GOLD thread, or spun gold, is a flatted 

 gold, wrapped or laid over a thread of 

 silk, by twisting it with a wheel and iron 

 bobbins. 



Manner of forming gold wire and gold 

 thread, both round and flat. First, an in* 

 got of silver, of 24 pounds, is forged into 

 a cylinder of about an inch in diameter : 

 then it is drawn through eight or tea 

 holes, of a large, coarse, wire-drawing iron, 

 both to finish the roundness, and to re- 

 duce it to about three-fourths of its for- 

 mer diameter. Tins done, they file it 

 very carefully all over, to take off any 

 filth remaining on the forge ; then they 

 cut it in the middle ; and thus make two 

 equal ingots thereof, each about 26 inches 

 long, which they draw through several 

 new holes, to take off any inequalities 

 the file may have left, and to render it as 

 smooth and equable as possible. 



The ingot thus far prepared, they heat 

 it in a charcoal fire; then taking some 

 gold leaves, each about four inches 

 square, and weighing twelve grains, they 

 join four, eight, twelve, or sixteen of 

 these, as the wire is intended to be more 

 or less gilt, and when they are so joined 

 as only to form a single leaf, they rub the 

 ingots reeking hot with a burnisher. 

 These leaves, being 1 thus prepared, they 

 apply over the whole surface of the ingot, 

 to the number of six, over each other, 

 burnishing or rubbing them well down. 

 When gilt, the ingots are laid anew in a 

 coal fire ; and when raised to a certain 

 degree of heat, they go over them a se- 

 cond time, both to solder the gold more 

 perfectly, and to finish the polishing. The 

 gilding finished, it remains to draw the 

 ingot into wire. 



In order to this, they pass it through 20 

 holes of a moderate drawing-iron, by 

 which it is brought to the thickness of the 

 tag of a lace : from this time the ingot 

 loses its name, and commences gold wire. 

 Twentv holes more of a lesser iron leaves 



I, 



