The price, therefore, of the coarse, and still more that of the precious metals, at the most fertile mines in the world, must necessarily more or less affect their price at every other in it. The price of copper in Japan must have some influence upon its price at the copper mines in Europe. The price of silver in Peru, or the quantity either of labour or of other goods which it will purchase there, must have some influence on its price, not only at the silver mines of Europe, but at those of China. After the discovery of the mines of Peru, the silver mines of Europe were, the greater part of them, abandoned. The value of silver was so much reduced, that their produce could no longer pay the expense of working them, or replace, with a profit, the food, clothes, lodging, and other necessaries which were consumed in that operation. This was the case, too, with the mines of Cuba and St. Domingo, and even with the ancient mines of Peru, after the discovery of those of Potosi.
The price of every metal, at every mine, therefore, being regulated in some measure by its price at the most fertile mine in the world that is actually wrought, it can, at the greater part of mines, do very little more than pay the expense of working, and can seldom afford a very high rent to the landlord. Rent accordingly, seems at the greater part of mines to have but a small share in the price of the coarse, and a still smaller in that of the precious metals. Labour and profit make up the greater part of both.
A sixth part of the gross produce may be reckoned the average rent of the tin mines of Cornwall, the most fertile that are known in the world, as we are told by the Rev. Mr. Borlace, vice-warden of the stannaries. Some, he says, afford more, and some do not afford so much. A sixth part of the gross produce is the rent, too, of several very fertile lead mines in Scotland.
In the silver mines of Peru, we are told by Frezier and Ulloa, the proprietor frequently exacts no other acknowledgment from the undertaker of the mine, but that he will grind the ore at his mill, paying him the ordinary multure or price of grinding. Till 1736, indeed, the tax of the king of Spain amounted to one fifth of the standard silver, which till then might be considered as the real rent of the greater part of the silver mines of Peru, the richest which have been known in the world. If there had been no tax, this fifth would naturally have belonged to the landlord, and many mines might have been wrought which could not then be wrought, because they could not afford this tax. The tax of the duke of Cornwall upon tin is supposed to amount to more than five per cent. or one twentieth part of the value; and whatever may be his proportion, it would naturally, too, belong to the proprietor of the mine, if tin was duty free. But if you add one twentieth to one sixth, you will find that the whole average rent of the tin mines of Cornwall, was to the whole average rent of the silver mines of Peru, as thirteen to twelve. But the silver mines of Peru are not now able to pay even this low rent; and the tax upon silver was, in 1736, reduced from one fifth to one tenth. Even this tax upon silver, too, gives more temptation to smuggling than the tax of one twentieth upon tin; and smuggling must be much easier in the precious than in the bulky commodity. The tax of the king of Spain, accordingly, is said to be very ill paid, and that of the duke of Cornwall very well. Rent, therefore, it is probable, makes a greater part of the price of tin at the most fertile tin mines than it does of silver at the most fertile silver mines in the world. After replacing the stock employed in working those different mines, together with its ordinary profits, the residue which remains to the proprietor is greater, it seems, in the coarse, than in the precious metal.
Neither are the profits of the undertakers of silver mines commonly very great in Peru. The same most respectable and well-informed authors acquaint us, that when any person undertakes to work a new mine in Peru, he is universally looked upon as a man destined to bankruptcy and ruin, and is upon that account shunned and avoided by every body. Mining, it seems, is considered there in the same light as here, as a lottery, in which the prizes do not compensate the blanks, though the greatness of some tempts many adventurers to throw away their fortunes in such unprosperous projects.
As the sovereign, however, derives a considerable part of his revenue from the produce of silver mines, the law in Peru gives every possible encouragement to the discovery and working of new ones. Whoever discovers a new mine, is entitled to measure off two hundred and forty-six feet in length, according to what he supposes to be the direction of the vein, and half as much in breadth. He becomes proprietor of this portion of the mine, and can work it without paving any acknowledgment to the landlord. The interest of the duke of Cornwall has given occasion to a regulation nearly of the same kind in that ancient dutchy. In waste and uninclosed lands, any person who discovers a tin mine may mark out its limits to a certain extent, which is called bounding a mine. The bounder becomes the real proprietor of the mine, and may either work it himself, or give it in lease to another, without the consent of the owner of the land, to whom, however, a very small acknowledgment must be paid upon working it. In both regulations, the sacred rights of private property are sacrificed to the supposed interests of public revenue.
The same encouragement is given in Peru to the discovery and working of new gold mines; and in gold the king’s tax amounts only to a twentieth part of the standard rental. It was once a fifth, and afterwards a tenth, as in silver; but it was found that the work could not bear even the lowest of these two taxes. If it is rare, however, say the same authors, Frezier and Ulloa, to find a person who has made his fortune by a silver, it is still much rarer to find one who has done so by a gold mine. This twentieth part seems to be the whole rent which is paid by the greater part of the gold mines of Chili and Peru. Gold, too, is much more liable to be smuggled than even silver; not only on account of the superior value of the metal in proportion to its bulk, but on account of the peculiar way in which nature produces it. Silver is very seldom found virgin, but, like most other metals, is generally mineralized with some other body, from which it is impossible to separate it in such quantities as will pay for the expense, but by a very laborious and tedious operation, which cannot well be carried on but in work-houses erected for the purpose, and, therefore, exposed to the inspection of the king’s officers. Gold, on the contrary, is almost always found virgin. It is sometimes found in pieces of some bulk; and, even when mixed, in small and almost insensible particles, with sand, earth, and other extraneous bodies, it can be separated from them by a very short and simple operation, which can be carried on in any private house by any body who is possessed of a small quantity of mercury. If the king’s tax, therefore, is but ill paid upon silver, it is likely to be much worse paid upon gold; and rent must make a much smaller part of the price of gold than that of silver.
The lowest price at which the precious metals can be sold, or the smallest quantity of other goods for which they can be exchanged, during any considerable time, is regulated by the same principles which fix the lowest ordinary price of all other goods. The stock which must commonly be employed, the food, clothes, and lodging, which must commonly be consumed in bringing them from the mine to the market, determine it. It must at least be sufficient to replace that stock, with the ordinary profits.
Their highest price, however, seems not to be necessarily determined by any thing but the actual scarcity or plenty of these metals themselves. It is not determined by that of any other commodity, in the same manner as the price of coals is by that of wood, beyond which no scarcity can ever raise it. Increase the scarcity of gold to a certain degree, and the smallest bit of it may become more precious than a diamond, and exchange for a greater quantity of other goods.