After treating of the amalgamation in use in America, it remains for us to touch upon a very important problem, that of the quantity of mercury annually required by the mines of New Spain. Mexico and Peru depend very much upon the abundance and low price of the mercury for the quantity of silver which they produce. When the mercury fails them, which happens often in periods of maritime war, the mines are not so briskly worked; and the ores accumulate on their hands without their being able to extract the silver from them. Rich proprietors, who possess in their magazines ores to the amount of two or three millions of francs, are frequently in want of the necessary money to make head against the daily expenses of their mines. On the other hand, the more mercury is wanted in Spanish America, either on account of the flourishing state of the mines, or the process of amalgamation followed there, the more the price of this metal rises in Europe. The small number of countries which nature has supplied with it, Spain, the department of Mont-Tonnerre, Carniola, and Transylvania, gain by this rise; but the districts of silver mines in which the process of amalgamation is the more desirable, as they are in want of the necessary combustibles for smelting, feel very disadvantageously the necessity for great importations of mercury into America. Mexico consumes annually upwards of 2,000,000 pounds troy of mercury. In 1803, a very useful CONSUMPTION OF MERCURY. 221 project was formed in Spain of supplying Mexico for several years, in order that in the unforeseen case of a war, the amalgamation might not be impeded by the want of mercury; but this project (del requesto) shared the fate of so many others which have never been executed. Before 1770, when the working of mines was far from being so considerable as at present, New Spain received no other mercury but that of Almaden and Huancavelica. The German mercury furnished by the Austrian Government, of which the greatest part is from Idria, was only introduced into Mexico after the falling in of the subterraneous works of Huancavelica, at a time when the mine of Almaden was inundated in the greatest part of its works, and yielded a very inconsiderable produce. But in 1800 and 1802, this last mine was again in such a flourishing state, that it could alone have furnished more than 20,000cwt. of mercury per annum, and there were sufficient grounds to conceive the hope of a termination of the necessity for recurring to German mercury, for the supply of Mexico and Peru. There have been years, when 10 or 12,000cwt. of this last mentioned mercury have been imported at Vera Cruz. Upon the whole, from 1762 to 1781, the amalgamation works of New Spain destroyed the enormous quantity of 25,124,200lbs. troy, of which the value in America amounted to more than 2,400,0007. When the price of mercury has progressively lowered, the working of the mines has gone on increasing. In 1590, under the Viceroy Don Luis de Velasco II., a cwt. of mercury was sold in Mexico for 407. 10s. But in the 18th century, the value of this metal had diminished to such a degree, that in 1750 the court distributed it to the miners at 177. 15s. Between 1767 and 1776, its price was 137. 9s. per cwt. In 1777, under the administration of the Minister Galvez, a royal decree fixed the price of the mercury of Almaden at 87. 17s. 6d., and that of Germany at 137. 13s. At Guanaxuato, these two sorts of mercury are increased by the expensive carriage on the backs of mules, from 8s. 8d. to 10s. 10d. per cwt. The impartial distribution of mercury (el repartimiento del azogue) is of the greatest consequence to the prosperity of the mines of New Spain. Unfortunately, however, the viceroys and those persons who were about them, under the old government, were jealous of the right of administering this branch of the royal revenue. They knew very well that to distribute mercury, and especially that of Almaden, which is one third cheaper than that of Idria, was to concede a favour; and in the colonies, as every where else, it is profitable to favour the richest and most powerful individuals. From this state of things, the poorest miners, those of Tasco, Temascaltepec, or Copala, CHINESE MERCURY. 223 could not procure mercury, when the great works of Guanaxuato and Real del Monte had it in abundance. The following table* proves the influence of the price of mercury on its consumption. The diminution of this price, and the freedom of trade with all the ports of Spain, have jointly contributed to the progress of mining. It was known in Mexico in 1782, that China possesses mercury mines; and it was imagined that nearly 15,000 cwt. might be annually drawn from Canton. The Viceroy Galvez sent thither a cargo of otter skins by way of exchange for the mercury; but this project, wise in itself, was badly executed. The Chinese mercury obtained from Canton and Manilla was impure, and contained a great deal of lead; and its price amounted to 177. 6s. 8d. the cwt. Even at this price, only a very small quantity could be procured. Since 1793, this * Influxo del precio del azogue sobre su consumo, por Don Antonio del Campo Marin. (MS.) important object has been totally lost sight of; yet it is deserving of the utmost attention, especially at a time when the Mexicans experience great difficulty in procuring mercury from the Continent of Europe. From all the researches which I could make, the whole of Spanish America, namely, Mexico, Peru, Chili, and the kingdom of Buenos Ayres, (for elsewhere the process of amalgamation is unknown,) annually consume more than 25,000 cwt. of mercury, the price of which in the Colonies amounts to more than 250,000l. sterling. M. Heron de Villefosse, in an interesting table which contains the quantity of each metal extracted from the mines over the whole globe, estimates the mercury annually drawn from those of Europe at 36,000 cwt. From these data we find that mercury is, after cobalt, the rarest of all metals, and that it is even twice as rare as tin. The following table indicates the quantity of mercury lost in the processes of amalgamation, used in different districts of mines, to extract the silver from the ore. A loss (perdida y consumo) of 100lbs. of mercury is computed lbs. troy of silver. In the mines of Guanaxuato, for about laxara 65 58 |