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.

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 working. It appears, on the contrary, from the interesting information which we owe to the labours of

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MERCURY.

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 shareholders?

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 If they discover no single mine their mountains. 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,

will be more attentive to their common interests: it becomes, therefore, of consequence to observe the indications of mercury in South America. Mexico and Peru, instead of receiving this metal from Europe, will one day, perhaps, be able to supply the Old world with it.

We may also hope that, in proportion as the inhabitants of the New world shall learn to profit by the natural wealth of the soil, the improvement of chemical knowledge will discover processes of amalgamation by which less mercury is consumed. By diminishing the consumption of this metal, and increasing the produce of the indigenous mines, the American miners will gradually learn to dispense with the mercury of Europe and China.

To complete the view of the mineral substances of New Spain, it remains for us to name coal, salt, and soda. The coal, of which I saw in the valley of Bogota beds at 7,500 feet of elevation above the level of the sea, in general appears to be very rare in the Cordilleras. In the kingdom of New Spain it has only yet been discovered in New Mexico; it is however probable that it may be found in the secondary formations which extend to the north and north-west of the Rio Colorado, as well as in the plains of San Luis Potosi and Texas. There is already a coal mine near the sources of the Rio Sabina. In general, coal and rock salt abound to the west of the Sierra Verde near the lake of Timpanogos, in Upper Louisiana, and in those vast northern regions situated

between the stony mountains of Mackenzie and Hudson's Bay.

Deposits of coal abound beyond the tropics in New Mexico, in the middle of the salt plains of Moqui and Nabajoa, and to the east of the Rocky Mountains, as also towards the sources of the Rio Sabina, in that immense basin covered with secondary formations, in which flow the Missouri and the Arkansas.

An able engineer, M. Lafond, whose map throws much light on these countries, observes, that eight leagues north from the post of Chichi there are hills abounding in coal, from which a subterraneous noise is heard at a distance like the discharge of artillery. Does this curious phenomenon announce a disengagement of hydrogen produced by a bed of coal in a state of inflammation?

In the whole inhabited part of New Spain, there is no rock salt like that of Zipaquira in the kingdom of Santa Fe, or of Wieliczka in Poland. The muriate of soda is no where found collected in banks or masses of considerable volume; it is merely disseminated in the argillaceous soil which covers the ridge of the Cordilleras.

The most abundant salt mine of Mexico is the lake of the Peñon Blanco, in the intendancy of San Luis Potosi, of which the bottom is a bed of clay which contains from 12 to 13 per cent. of muriate of soda. We ought also to observe, that were it not for the amalgamation of silver ores, the con