GOLD 



2524 



GOLD 



does water. On account of its resistance to 

 oxidation, the alchemists called gold a noble 

 metal or the king of metals. However, chlorine 

 it cannot resist, 

 and in water sat- 

 urated with that 

 gas it is dissolved 

 as readily as is 

 salt in hot water. 

 A mixture of 

 nitric and hydro- 

 chloric acid also 

 dissolves gold 

 readily, owing to 

 the liberation of 



29ft 



The Worlds Gold 



Coin and 



Bullion 



chlorine by the 

 interaction of the 



royal 



THE GOLD OF THE 



WORLD 



All the money of the world, 

 except that of the few coun- 

 t w o acids. On tries which have a silver, 

 .. ... nickel or paper standard, is 

 account of this based on about $8,000,000,000 



n n t h p in gold - A cube of gold of this 

 e value would measure twenty- 



metal the nlne feet on eacn edge. The 

 , large automobiles in the illus- 

 alchemists named tration help to a realization 



this mixture of the slze of such a solld " 

 of acids aqua regia, that is, the royal water, 

 When this solution is evaporated yellow crys- 

 tals of auric chloride are obtained. This gold 

 chloride is used in "toning" (that is, modifying 

 the color of) photographs. In the presence of 

 air, a solution of sodium (or potassium) cya- 

 nide dissolves gold. This fact is utilized in 

 extracting the metal from its ores. 



How Gold Exists in Nature. Long, long ago, 

 people did not delve deep in the earth for 

 their supply of gold. They just took what 

 nature had left ready for them on the surface. 

 Gold was frequently found then, as it is some- 

 times found to-day, mixed with the sand and 

 gravel along a river course. When so found 

 it is in a pure state or mixed with silver, and 

 occurs in all sizes from tiny particles like 

 grains of glistening sand to nuggets of fair 

 size. So far as is known, the largest nugget 

 ever found thus free in the sand and gravel 

 was discovered in Victoria, Australia, and 

 weighed 183 pounds. It is hard to conceive 

 of the intense excitement which must have 

 prevailed when this $50,000 lum of gold was 

 picked up. 



To obtain gold from such alluvial sources, 

 only a simple washing is necessary. These 

 surface deposits are called placer mines, and 

 most of them are shallow and quickly ex- 

 hausted. Naturally they are the more con- 

 spicuous and enticing sources of gold, and in 

 almost every case where the discovery of gold 

 has been followed by the rush of thousands to 



the spot, it has been metal of this easily at- 

 tainable variety that has been first sought. 

 The "forty-niners," for example, who formed 

 the endless caravan across the desert to Cali- 

 fornia, were seeking "placer" gold, and the 

 first findings in the Klondike region, in Aus- 

 tralia and in South Africa were of the same 

 variety. At first, every man washed his own 

 gold in a simple sheet-iron pan, but later 

 hydraulic machinery was introduced powerful 

 machinery which by means of its forcibly- 

 driven streams of water tears out gravel and 

 soil and boulders in the gold-bearing regions 

 and, by a system of gratings, separates the gold 

 from the worthless material. This is a wasteful 

 process wasteful not of gold, but of soil and 

 it has been practically forbidden in well-settled 

 places, as in California. To take its place, 

 in sections where placer gold exists, another 

 method, which employs dredges, has been in- 

 troduced. 



All gold does not exist in this free state. 

 Much of it exists in ores or gold-bearing rock, 

 and must be mined like any other metal, by 

 means of great shafts sunk into the earth. 

 In Western Australia, Transylvania and Colo- 

 rado large quantities of a compound of gold 

 with tellurium (formula Au Te2) are found. 

 This is a gray or black ore, though an admix- 

 ture of free gold sometimes gives it a brassy 

 color. Gold-bearing ores are especially plenti- 

 ful in mountainous regions. 



Taking Gold from the Ores. After the rock 

 with its precious admixture of gold is brought 

 to the surface, there remains much to be done 

 before the gold is in an easily recognizable state. 



The miner has no nuggets of pure gold to 

 carry about in his pocket, or to tie up into 

 a long string in the fascinating manner of a 

 Bret Harte hero; it was placer gold entirely 

 with which these men dealt. The treatment 

 given gold-bearing ore depends largely on what 

 other substances enter into its composition, 

 but the preliminary process is usually the same. 

 The ore is crushed and ground to a fine powder 

 by a stamping machine, and is then passed 

 over copper plates covered with mercury. This 

 substance has a strong affinity for gold, and 

 as the ore passes over it, it draws out the 

 gold particles and lets the other material pass 

 by. The pulpy mass of mercury and gold 

 which results is known as amalgam. This is 

 first squeezed, to force out the excess mercury, 

 and the hard amalgam which remains is heated 

 until the mercury distils and passes off in 

 vapor, leaving the gold. 



