county of Derby in England, traverse those galleries, which communicate with one another.

The veins of Tehuilotepec are in general western (spatgänge); they are from two to three metres in extent *, and being separated from the rock by a list of clayey loam, they form several lateral branches, which enrich the principal vein where they accompany it (se trainent). Their structure has this particularity, that the metallic mineral is rarely disseminated throughout all the gangue, but collected in a single band, which is sometimes near the roof, and sometimes near the wall of the vein. In general, the mineral depositories of Tasco and Tehuilotepec are extremely inconstant in their produce. As to the nature of the mass of which they are constituted, I perceived four very different formations of veins, viz.

1. Brown, red, and yellow oxides of iron, in which native and sulphuretted silver are disseminated in impalpable particles; cellular brown ironstone, specular iron, a little galena, and magnetic iron, and blue carbonate of copper. This formation, analogous to that of the pacos of Fuentestiana, and Pasco in Peru, is designated at Tehuilotepec, by the name of tepostel. It is found at small depths from the

* From 6 to 9 feet. Trans.

surface (in ausgehenden) in the mines of San Miguel, San Estevan, and La Compaña, near Tasco, as well as at the Cerro de Garganta, near Mescala. The tepostel, is generally not so rich as the Pasco of Peru; but is so much the richer at Tasco, as the oxide of iron is more mixed with azure of copper; but it generally, however, does not contain more than four ounces of silver per quintal.

2. Calcareous spar, a little galena, and transparent lamellar gypsum, containing drops of water with air, and filiform native silver. This small and very remarkable formation, which has been also observed in the mountains of Saltzbourg, is found at the depth of more than 100 metres* on the vein of Trinidad, which is the continuation of the vein of San Miguel, in a point where the wall is not gypsum, but compact limestone.

3. Light-red silver, brittle vitreous silver (sprödglaserz), much yellow blende, galena, very little of iron pyrites, calcareous spar, and milk quartz. This formation, which is the richest of all, displays the remarkable phenomenon, that the minerals the most abundant in silver, form spheroidal balls, from ten to twelve centimetres in diameter t, in which red silver, mixed with brittle vitreous silver, and

* 328 feet. Trans.

† From 3.93 to 4.71 inches. Trans.

native silver, alternate with bands of quartz. These balls, which have been seldom seen but between 15 and 60 metres* of depth, are nidulating in a gangue of calcareous and brownspar. They have been observed in the three veins of San Ignacio, Dolores, and Perdon, of which the masses are filled with druses, lined with beautiful crystals of carbonate of lime.

4. Much argentiferous galena, which is richer in silver in proportion as the separated pieces are of smaller grain; much yellow blende; little pyrites; quartz, and calcareous spar, in the mines of Socabon del Re, and de la Marquesa.

All these veins run through a table land of from 17 to 1800 metres in elevation † above the surface of the sea, which enjoys a temperate climate, very favourable to the cultivation of the cerealia of the Old Continent.

When we take a general view of the mining operations of New Spain, and compare them with those of the mines of Freiberg, the Hartz, and Schemnitz, we are surprised at still finding in its infancy, an art which has been practised in America for these three centuries, and on which, according to the vulgar prejudice, the

prosperity of these ultramarine establishments depends. The causes of this phenomenon cannot escape those who, after visiting Spain, France, and the western parts of Germany, have seen that mountainous countries still exist in the centre of civilized Europe, in which the mining operations partake of all the barbarity of the middle ages. The art of mining cannot make great progress, where the mines are dispersed over a great extent of ground, where the government allows to the proprietors the full liberty of directing the operations without controul, and of tearing the minerals from the bowels of the earth, without any consideration of the future. Since the brilliant period of the reign of Charles the 5th, Spanish America has been separated from Europe, with respect to the communication of discoveries useful to society. The imperfect knowledge which was possessed in the 16th century relative to mining and smelting, in Germany, Biscay, and the Belgic provinces, rapidly passed into Mexico and Peru, on the first colonization of these countries; but since that period, to the reign of Charles the third, the American miners have learned hardly any thing from the Europeans, but the blowing up with powder those rocks which resist the

*

*This art was only introduced into the mines of Europe towards the year 1613. (Daubuisson, t. i. p. 95.)

pointrole. This King and his successor have shewn a praiseworthy desire of imparting to the colonies all the advantages derived by Europe from the improvement in machinery, the progress of chemical science, and their application to metallurgy. German miners have been sent at the expence of the court to Mexico, Peru, and the kingdom of new Grenada; but their knowledge has been of no utility, because the mines of Mexico are considered as the property of the individuals, who direct the operations, without the government being allowed to exercise the smallest influence.

We shall not here undertake to detail the defects which we believe we have observed in the administration of the mines of New Spain, but shall confine ourselves to general considerations, remarking whatever appears to us worthy of fixing the attention of the European traveller. In the greatest number of the Mexican mines the operations with the pointrole, which requires the greatest address on the part of the workman, are very well executed. The mallet might indeed be somewhat less heavy; it is the same tool which the German miners used in the time of Charles the 5th. Small moveable forges are placed in the interior of the mines, to re-forge the point of the pointroles, when they are unfit for working.

I