Gold is the heaviest of all metals excepting platina; it is neither very elastic nor hard; but so malleable and ductile, that it may be drawn into very fine wire, or beaten into leaves so thin as to be carried away by the slightest wind. Dr. Black has calculated, that it would take fourteen millions of films of gold, such as is on some fine gilt wire, to make the thickness of one inch: whereas fourteen million leaves of common printing paper make near three quarters of a mile. According to Fourcroy, the ductility of gold is such, that one ounce of it is sufficient to gild a silver wire more than thirteen hundred miles long. Such is the tenacity of gold, that a wire 1-16th of an inch in diameter will support a weight of 500 pounds without breaking. Gold may be known from all other metals by its bright yellow color, and its weight. Its specific gravity is 19.3; when heavier, it must be combined with platina; when lighter, and of a deep yellow color, it is alloyed with copper; and if of a pale color, with silver.
Arabia had formerly its gold mines. The gold of Ophir, so often mentioned in Scripture, must be that which was procured in Arabia, on the coast of the Red Sea. We are assured by Sanchoniathon, and by Herodotus, quoted by Eusebius, that the Phœnicians carried on a considerable traffic in gold, even before the days of Job, who thus speaks of it, “Then shall thou lay up gold as dust, and the gold of Ophir as stones of the brooks.” Gold is found in Peru, as well as in several other parts of the world. It generally occurs in a metallic state, and most commonly in the form of grains. It frequently is met with in the ores of other metals, but is chiefly found in the warmer regions of the earth. It abounds in the sands of many African rivers, in South America, and in India. Several rivers in France contain gold in their sands. It has also been discovered in Hungary, Sweden, Norway and Ireland. Near Pamplona, in South America, single laborers have collected upwards of £200 worth of wash-gold in a day. In the province of Sonora, the Spaniards discovered a plain, fourteen leagues in extent, in which they found wash-gold at the depth of only 16 inches; the grains were of such a size that some of them weighed 72 ounces, and in such quantities, that in a short time, with a few laborers, they collected 1,000 marks, (equal in value to £31,219 10s. sterling,) even without taking time to wash the earth which had been dug. They found one grain which weighed 132 ounces; this is deposited in the royal cabinet at Madrid, and is worth £500.[104] The native gold found in Ireland was in grains, from the smallest size to upwards of two ounces. Only two grains were found of greater weight, one of which weighed 5, and the other 22 ounces.[105] Gold mines were formerly worked in Scotland; and indeed now, grains of this metal are often found in brooks after a great flood. It has been said, that at the nuptials of James V, covered dishes filled with coins of Scotch gold were presented to the guests by way of dessert. Standard gold of Great Britain is twenty-two parts pure gold, and two parts copper; it is therefore called gold of “twenty-two carots fine.” Some have thought that Moses made use of sulphuret of potass to render the calf of gold adored by the Israelites soluble in water. Stahl wrote a long dissertation to prove that this was the case.
Silver is a heavy, sonorous, brilliant, white metal; exceedingly ductile, and of great malleability and tenacity. It possesses these latter properties in so great a decree, that it may be beaten into leaves much thinner than any paper, or drawn into wire as fine as a hair without breaking. Fifty square inches of silver leaf weigh not more than a grain. The specific gravity of silver is 10.500. When perfectly pure, it is a very soft metal. To know when it is pure, heat it in a common fire, or in the flame of a candle: if it be alloyed, it will become tarnished; but if it be pure, it will remain perfectly white. Our standard silver is formed with fifteen parts pure silver, and one part copper.
Silver is found in various parts of the world in a metallic state; also in the states of a sulphuret, a salt, and an oxide. Native silver is found chiefly in the mines of Potosi. Sulphuret of silver occurs in the silver mines of Germany, Hungary, Saxony and Siberia. Oxides of silver are also common in some of the silver mines in Germany. Silver has lately been found in a copper-mine in Cornwall.[106] Most of our lead mines also afford it, particularly some in Scotland. In the county of Antrim, in Ireland, there is a mine so rich, that every thirty pounds of lead ore is said to produce one pound of silver. By the silver which was produced from the lead mines in Cardiganshire, Sir Hugh Middleton is said to have cleared two thousand pounds a month, and that this enabled him to undertake the great work of bringing the New River from Ware to London.
Silver was used in commerce eleven hundred years before the foundation of Rome. Moses, says, “And Abraham weighed to Ephron the silver, which he had named in the audience of the sons of Heth, four hundred shekels of silver, current money with the merchant.” At this period silver was not coined, but being only in bars, or ingots, in commerce was always weighed. In the museum of the Academy of Sciences at St. Petersburgh, is a piece of native silver from China of such firmness, that coins have been struck from it without its having passed through the crucible.[107]
Platina, the heaviest of all metals, is nearly as white as silver, and difficultly fusible, though by great labor may be rendered malleable, so as to be wrought into utensils like other metals. It will resist the strongest heat of our fires without melting, and, like iron, is capable of being welded when properly heated. It is found in grains, in a metallic state, at St. Domingo: and also at Santa Fe, in Peru, in the language of whose inhabitants it means little silver. It has recently been discovered in an ore of silver found in Estremadura, existing in its metallic form. This metal was first introduced into England by Charles Wood, who brought it from Jamaica in the year 1741. It has been drawn into wire less than the two thousandth part of an inch in diameter. The specific gravity of hammered platina is 23.66, which is more than double that of lead.
Mercury, in the temperature of our atmosphere, is a fluid metal, having the appearance of melted silver: in this state it is neither ductile nor malleable; very volatile when heated; extremely divisible; and is the heaviest of all metals except platina and gold. We see it always in a fluid state, because it is so fusible that a small portion of caloric will keep it in a state of fluidity; but when submitted to a sufficient degree of cold, is similar to other metals, and may be beaten into plates. It has been determined, that at 39 degrees below zero of Fahrenheit’s thermometer is the point at which the congelation of mercury takes place. In the winter of 1799, Mr. Pepys froze 56 pounds of it into a solid and malleable mass. At Hudson’s Bay, frozen mercury has lately been reduced to sheets as thin as paper, by beating it upon an anvil that had previously been reduced to the same temperature. It is a substance so volatile that it may be distilled like water; and is sometimes purified in this way from mixture with other metals, being often adulterated with lead and bismuth. It is also so elastic when in a state of vapor, that it is capable of bursting the strongest vessels. According to Mr. Biddle, its specific gravity at 47 degrees above zero is 13.545; but when frozen into a solid at 40 below zero, 15.612.
This metal is brought to Europe from the East Indies and Peru; but is found in greater abundance at Almaden in Spain, where it is extracted from the ore by distillation. The quicksilver mine of Guanca Velica, in Peru, is 170 fathoms in circumference, and 480 deep. In this profound abyss are streets, squares, and a chapel where religious mysteries on all festival occasions are celebrated. Millions of flambeaux are continually burning to enlighten this subterranean abode. This mine generally affects those who work in it with convulsions. Notwithstanding this, the unfortunate victims of an insatiable avarice are crowded all together, and plunged naked into this abyss. Tyranny has invented this refinement in cruelty, to render it impossible for any thing to escape its restless vigilance.
“Thus in the dark Peruvian mine confin’d,
Lost to the cheerful commerce of mankind,