When we distinguish those periods in which the progress of mining has been most rapid, we find the following results :

This table, along with the preceding, proves that the periods during which the wealth of the mines have most increased, are from 1736 to 1745, from 1777 to 1783, and from 1788 to 1798; but the increase in general has been so little in proportion to the space of time, that the total produce of the mines was:

COPPER-TIN-IRON.

121

tripled in fifty-two years, and sextupled in a hundred years.

After gold and silver, it remains for us to speak of the other metals, called common metals, the working of which, as we have already stated in the beginning of this chapter, has been very much neglected. Copper is found in a native. state, and under the forms of vitreous and oxidulated copper, in the mines of Ingaran, a little to the south of the Volcano of Jorullo, at San Juan Guetamo, in the intendancy of Valladolid, and in the province of New Mexico. The Mexican tin

is obtained by means of washing, from the alluvial soil of the intendancy of Guanaxuato, near Gigante, San Felipe, Robledal and San Miguel el Grande, as well as in the intendancy of Zacatecas between the towns of Xeres and Villa Nueva. One of the ores of tin most common in Mexico is the wood tin of the English mineralogists. It appears that this mineral is originally found in veins which traverse trap-porphyries; but the natives, instead of working these veins, prefer the extracting of tin from the earth brought down the ravines. The intendancy of Guanaxuato in 1802 produced nearly 110 tons of copper, and 5 tons of tin.

The iron mines are more abundant than is generally believed, in the intendancies of Valladolid, Zacatecas, and Guadalaxara, and especially in the provincias internas.

R

These mines are only wrought with any degree of spirit during a period of maritime war, when a stop is put to the importation of steel and iron from Europe. The veins of Tecalitan, near Colima, were successfully wrought ten years ago, and afterwards abandoned. Ores of compact red iron-stone have been observed in the intendancy of San Luis Potosi near Catorce. I saw crystallized micaceous iron, near the village of Santa Cruz, east from Celaya, on the fertile table-land extending from Queretaro to Guanaxuato.

Lead, which is very rare in the north of Asia, abounds in the mountains of calcareous formation, contained in the north-east part of New Spain. The lead mines are not wrought with so much spirit as might be desired in a country where the fourth part of all the silver minerals are smelted.

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to

Among the metals of which the use is the most limited, we have to name zinc, which is found, under the form of brown and black blende, in the veins of Ramos, Sombrerete, Zacatecas, and Tasco; antimony, which is common Catorce and Los Pozuelos, near Cuencame; arsenic, which is found among the minerals of Zimapan, combined with sulphur, as orpiment. Cobalt, as far as I know, has never yet been discovered among the minerals of New Spain; and manganese, which M. Ramirez recently discovered in the island of Cuba, appears to me in general much less abundant in Equinoctial America, than

it is in the temperate climates of the Old Conti

nent.

Mercury, which is very remote from tin, with respect to its relative antiquity, or the period of its formation, is almost as uncommon as it is in every part of the globe. The inhabitants of New Spain have for centuries procured the mercury necessary in the process of amalgamation, partly from Peru and partly from Europe; and hence they are accustomed to consider their country as destitute of this metal. When however we consider the examinations carried on under the reign of Charles the Fourth, we must admit that few countries have so many indications of cinnabar, as the table-land of the Cordilleras from the 19th to the 22d degree of north latitude. In the intendancies of Guanaxuato and Mexico, we find it in many places. Sulphuret of mercury has been also discovered in the intendancy of Valladolid; at Los Pregones near Tasco, in the district of mines of the Doctor; and in the valley of Tenochtitlan to the south of Gassavé in the road from Mexico to Pachuca. The works carried on for the discovery of these different mineral repositories have been so frequently interrupted, and they have been conducted with so little zeal, and generally with so little intelligence, that it would be very imprudent to assert, as has been often done, that the mercury mines of New Spain are not worth work. ing. It appears, on the contrary, from the interesting information which we owe to the labours of

M Chovel, that the veins of San Juan de la Chica, as well as those of the Rincon del Centeno, and the Gigante, are very deserving of the attention of the Mexican miners. Was it to be expected that superficial works which were merely begun, should in the very first years yield a net profit to the share

holders ?

America in its present state is the tributary of Europe with respect to mercury; but it is probable that this dependence will not be of long duration, if the ties which unite the Colonies with the mother country remain long loosened, and if civilization is progressive in America. The spirit of enterprise and research will increase with the population; the more numerous are the inhabitants of the country, the more will they learn to appreciate the natural wealth which is contained in the bowels of their mountains. If they discover no single mine equal in wealth to the celebrated one of Huancavelica, they will work several at once, the united produce of which will render the importation of mercury from Spain and Carniola unnecessary. These changes will be so much the more rapidly effected, as the Peruvian and Mexican miners shall feel themselves impeded by the want of the metal necessary for amalgamation. The mineral depositaries of New Spain, if examined with care, and worked with constancy, may one day produce a very considerable quantity of mercury. The period approaches when the Spanish Colonies, being more united together,