GOLD GOLD COAST. 



501 



leaves are placed on the outsides ; the whole is then 

 put into a case of parchment, over which is drawn 

 another similar case, so that the packet is kept close 

 and tight on all sides. It is now laid on a smooth 

 block of marble, from 200 to 600 pounds in weight, 

 and the workman begins the beating with a round- 

 faced hammer, weighing sixteen pounds ; the packet 

 is turned, occasionally, upside down, and beaten with 

 strong but not acute strokes, till the gold is extended 

 nearly to an equality with the vellum leaves. The 

 packet is then taken to pieces, and each leaf of gold 

 is divided into four with a steel knife. The 600 

 pieces thus produced are interlaid with pieces of ani- 

 mal membrane, from the intestines of the ox, of the 

 same dimension and in the same manner as the 

 vellum. The beating is continued, but with a lighter 

 hammer, called the shoddering hammer, and weigh- 

 ing about twelve pounds, till the gold is brought to 

 the same dimensions as the interposed membrane. It 

 is now again divided into four, by means of a piece 

 of cane, cut to an edge, the leaves being by this time 

 so light, that any accidental moisture, condensing on 

 an iron blade, would cause them to adhere to it. The 

 2400 leaves hence resulting are parted into three 

 packets, with interposed membrane as before, and 

 beaten with the finishing or gold hammer, weighing 

 about ten pounds, till they acquire an extent equal 

 to the former. The packets are now taken to pieces, 

 and the gold leaves, by means of a cane instrument 

 and the breath, are laid flat on a cushion of leather, 

 and cut, one by one, to an even square, by a cane 

 frame ; they are lastly laid in books of twenty-five 

 leaves each, the paper of which is previously smooth- 

 ed, and rubbed with red bole, to prevent them from 

 adhering. Gold wire, as it is called, is in fact only 

 silver wire gilt, and is prepared in the following 

 manner. A solid cylinder of fine silver, weighing 

 about twenty pounds, is covered with thick leaves of 

 gold, which are made to adhere inseparably to it, by 

 means of the burnisher : successive laminae are thus 

 applied, till the quantity of gold amounts to 100 

 grains for every pound troy of silver. This gilt 

 silver rod is then drawn successively through holes 

 made in a strong steel plate, till it is reduced to the 

 size of a thick quill, care being taken to anneal it 

 accurately after each operation. The succeeding 

 process is similar to the former, except that a mixed 

 metal, somewhat softer than steel, is employed for 

 the drawing plates, in order to prevent the gilding 

 from being stripped off ; and no further annealing is 

 requisite after, if it is brought to be as slender as a 

 crow-quill. When the wire is spun as thin as is ne- 

 cessary, it is wound on a hollow copper bobbin, and 

 carefully annealed by a very gentle heat : finally, it 

 is passed through a flatting-mill, and the process is 

 complete. According to doctor Halley, six feet in 

 length of the finest gilt-wire, before flatting, will 

 counterpoise no more than a grain ; and as the gold 

 is not quite , J , of the whole, a single grain of gold, 

 thus extended, will be 345 6 feet long, and only the 

 millionth part of an inch in thickness. 



The oxide of gold is used in staining porcelain, to 

 which it communicates a colour differing but slightly 

 from copper-red. For this purpose, it is precipitated 

 from its muriatic solution by sulphate of iron, and is 

 fixed by the oxide of bismuth, in the proportion of 

 one-twelfth to one-nineteenth. Such are the princi- 

 pal uses of gold and its oxide ; for its medicinal vir- 

 tues are of too doubtful a character to deserve men- 

 tion. We shall now pass to the description of the 

 ores of gold, their mode of occurring in nature, and 

 the means made use of for obtaining this metal from 

 them. 



Native gold is found crystallized in the forms of the 

 octahedron, the cube, and the dodecahedron, of which 



the cube is considered as the primary form. It also 

 occurs in filiform, capillary, and arborescent shapes ; 

 as, likewise, in leaves or membranes, and rolled 

 masses. It offers no indications of internal structure, 

 but, on being separated by mechanical violence, ex- 

 hibits a hackly fracture. Its colour comprises vari- 

 ous shades of gold yellow. Its specific gravity varies 

 from 14-8 to 19-2. It is commonly alloyed by cop- 

 per, silver, and iron, in very small proportion. Na- 

 tive gold exists in veins in primitive mountains, but 

 not in the greatest quantity in those which are es- 

 teemed to be of the oldest formation. Its immediate 

 gangue is generally quartz ; and it is associated with 

 the ores of silver, sulphuret of iron, lead, nickel, cop- 

 per, &c. It is often so minutely disseminated, that 

 its presence is detected only by pounding and wash- 

 ing the rocks in which it exists. But native gold is 

 more often found in the sand of rivers, in valleys and 

 plains, into which it has been carried, from its origi- 

 nal repositories, in the shape of larger or smaller, 

 generally flat pebbles, mingled with quartz. The 

 mountain of Vorospatak, near Abrudbanya in Tran- 

 sylvania, is a remarkable instance of a rock impreg- 

 nated throughout with a small portion of gold. It 

 has been worked to a considerable extent since the 

 time of the Romans ; it consists of greywacke and 

 porphyry. In a similar rock it is found in many 

 places along the chain of the Alps, and In the 

 Schlangenberg in Siberia. But the greatest quantity 

 of gold is obtained from the alluvial soils of several 

 islands in the Indian ocean, from the southern, mid- 

 dle, and ^ western parts of Africa, and from Brazil, 

 Mexico, and Peru. The sands of several European 

 rivers, also, as the Danube, the Rhine, and the 

 Rhone, afford small quantities of gold ; and, of late 

 years, it has been discovered in similar situations in 

 the United States of America, in the Carolinas and 

 Georgia. The mines of North Carolina are chiefly 

 wrought in the three ranges of counties between 

 Frederic and Charlotte, which lie in a direction about 

 N.E. and S.W., corresponding with the general line 

 of the coast. The most lucrative diggings have been 

 made in the counties of Mecklenburg and Cabarras ; 

 in the latter, a single lump of gold was found weigh- 

 ing twenty-eight pounds. The gold is not wholly ob- 

 tained from alluvion in these districts, but is occa- 

 sionally pursued in the quartz rock, which abounds 

 with cavities, often partly filled with decomposed iron 

 pyrites. Humboldt estimates the average product of 

 gold per year of South America and New Spain, at 

 between two and three millions ; while Europe fur- 

 nishes annually about one-twelfth this amount, the 

 greater part of which comes from the mines of Hun- 

 gary. The largest amount of gold from Georgia and 

 Carolina, coined in any one year, has been about 

 .70,000. The metallurgic treatment of the ores of 

 gold, where the gold is free, consists in submitting 

 them to the contact of mercury after they have been 

 crushed and rendered fine by washing. The levi- 

 gated ore and the mercury are agitated together, 

 until it is conceived that the amalgamation is perfect, 

 when the compound is exposed to a heat sufficiently 

 intense to volatilize the mercury, which is condensed , 

 ana recovered for successive operations. When gold 

 occurs intimately mingled with iron pyrites, the pro- 

 cess differs from that described above, only in that 

 it is necessary to roast the ore, in order to pulverize 

 it sufficiently to set it at liberty. 



GOLD-BEATING. See Gold. 



GOLD THREAD. The gold threat! commonly 

 used in embroidery, consists of threads of yellow silk, 

 covered by flattened gilt wire, closely wound upon 

 them by machinery. 



GOLD WIRE. See Gold. 



GOLD COAST; name given to a country of 



