Quick-silver mines

Wolfstein in Europe. The mine of Chica has been only yet wrought to the depth of fifty metres *; and it is found, and this geological fact is very remarkable, not in sandstone or slate, but in a true pitchstone porphyry, divided into balls with concentric layers, of which the interior is lined with mammillated hyalite (müllerisch-glass). The cinnabar and a little native mercury, are sometimes observed in the middle of the porphyritic rock at a very considerable distance from the vein. During my stay at Guanaxuato, only two mines were wrought in all Mexico; those of Lomo del Toro, near San Juan de Chica, and Nuestra Señora de los Dolores, a quarter of a league to the south-east of the Gigante. In the first of these mines a load of ore yields from two to three pounds of mercury; and the expences of working are very moderate. The mine of the Gigante, from which there is even drawn six pounds of mercury per load (carga) of ore, furnished from 70 to 80 pounds weekly; and it is wrought on the account of a rich individual, Don Jose del Maso, who has the merit of having first excited his countrymen during the last war to the working of the quicksilver mines, and the manufacture of steel. The cinnabar

* 164 feet. Trans.

+

extracted from the veins of the mountain del Fraile, near the Villa de San Felipe, occurs in a porphyry with base of hornstone, which, being traversed by veins of tin, is undoubtedly more antient than the pitchstone porphyry of Chica.

America in its present state is the tributary of Europe with respect to mercury; but it is probable, that this dependance will not be of long duration, if the ties which unite the Colonies with the mother country remain long loosened, and if the civilization of the human species in its progressive motion from East to West is concentrated in America. The spirit of enterprize and research will increase with the population; the more the country shall be inhabited, the more they will 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 Huancavelica, they will work several at once, by which the united produce will render the importation of mercury from Spain and Carniola unnecessary. These changes will be so much the more rapidly operated, as the Peruvian and Mexican miners shall feel themselves impeded by the want of the metal necessary for amalgamation. But let us enquire what would be the consequence to the silver

mines of America, if in the midst of the wars by which Europe is oppressed, the quicksilver mines of Almaden and Idria, should no longer be wrought.

I have mentioned the mineral depositories of New Spain, which if examined with care, and worked with constancy, may produce one day 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; and it becomes, therefore, of consequence to take a general view of the indications of mercury observable 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. I shall confine myself to the knowledge which I could obtain on the spot, and especially during my stay at Lima; and I shall only mention the points where cinnabar has been found, either in veins or beds. In several places, for example, at Portobello, and Santa Fe de Bogota, considerable quantities of native mercury have been collected at small depths in building houses; and this phenomenon has frequently fixed the attention of government. They forget that in a country where, for three centuries, bags filled with mercury have been transported on mules from province to province, this mercury

must necessarily have been scattered in the sheds, under which the beasts of burden, are unloaded, and in the quicksilver magazines established in towns. The mountains in general contain mercury in its native state, in very small portions only; and when in an inhabited place, or on a great road, we discover in the earth several kilogrammes collected together, we must believe that these masses originated in accidental infiltrations.

In the kingdom of New Granada, cinnabar is known in three different places, namely, in the province of Antioquia, in the Valle de Santa Rosa, east from the Rio Cauca; in the mountain of Quindiu, in the pass of the central cordillera between Ibague and Carthago, at the extremity of the Ravin of Vermellon; and lastly, in the province of Quito, between the village of Azogue and Cuenca. The discovery of the cinnabar of Quindiu is due to the patriotic zeal of the celebrated traveller Mutis, who in the months of August and September, 1786, at his own expense, caused the miners of Sapo to examine that part of the granitic cordillera which extends to the South from the Nevado de Tolima towards the Rio Saldaña, The ore of sulphuret of mercury is not only found in round fragments mixed with small grains of gold in the alluvial earth with which the Ravin (quebrada) de Vermel

lon at the foot of the table land of Ibague Viejo is filled; but they know the vein also from which the torrent appears to have detached these fragments, and which traverses the small ravin of Santa Ana. Near the village of Azogue to the north-west of Cuenca, the mercury is found, as in the department of Mont-Tonnerre, in a formation of quartzy sandstone with argillaceous cement. This sandstone is nearly 1400 metres in thickness, and contains fossil wood † and asphaltum. ‡ In the mountains of Guazun and Upar, situated to the north-east of Azogue, a vein of cinnabar traverses beds of clay filled with calcareous spar, and contained in sandstone. We discover there the remains of an old level of 120 metres in length §, and 11 pits very close to one another. It is believed in the country that this mine was wrought before Huancavelica, and that it was the discovery of the

*4592 feet. Trans.

+ I found beautiful pieces of 14 decimetres (4 feet English) in length at Silcai-Yacu between Delec and Cuenca.

At Porche and the western declivity of the mountains of Coxitambo, I was singularly struck with the geological relations between the sandstone formation of Cuenca and Azogue and the sandstone of the mines of Wolfstein and Münsterrappel, which I visited in 1790, and which also contain cinnabar, fossil wood, and petroleum.

393 feet. Trans.