mountain 4422 metres*. The discovery of the great mercury mine, is generally attributed to the Indian Gonzalo Abincopa or Navimcopa; but it is certain that it goes back to a period long before 1567, since the Incas made use of cinnabar in painting themselves, and procured it from the mountains of Palcas. The working of the mine of the Cerro de Santa Barbara on account of the Crown, began however only in the month of September, 1570, nearly the same year in which Fernandez de Velasco introduced the Mexican amalgamation into Peru.

Mercury is found in the environs of the town of Huancavelica, in two very different manners, in beds and in veins. In the great mine of Santa Barbara, the cinnabar is contained in a bed of quartz freestone of nearly 400 metres in thickness, and in a direction of hor. 10-11

* 14,506 feet. Trans. This measurement agrees very well with the assertion of Ulloa, who relates that he saw the barometer remain at the bottom of the mine of Hoyo Negro at 17. 2. 2; from which we may conIclude that the bottom of the mine was then 2159 toises, or 4208 metres of elevation above the level of the ocean (13,805 feet. Trans.). (Ulloa, Noticias Americanas, p. 279.) In this pit then the miners wrought in a point which is 500 metres (1640 feet), higher than the summit of the Peak of Teneriffe. In the Cerro de Hualgayoc, I have seen galleries of which the absolute height exceeded 4050 metres (13,287 feet. Trans.).

of the German compass, with an inclination of 64° towards the west. This freestone, analogous to that of the environs of Paris, and the mountains of Aroma and Cascas, in Peru, resembles pure quartz. The most part of the specimens which I examined in the geologi cal cabinet of the Baron de Nordenflycht, exhibit very little clayey cement. The quartz rock which contains the mercury minerals, forms a bed in a calcareous brescia, from which it is only separated in its wall and its roof, by a very thin stratum of slate clay (schieferthon), which has been frequently confounded with primitive slate. The brescia is covered with a formation of secondary limestone, and the fragments of compact limestone contained in the brescia, seem to indicate that the whole mass of the mountain of Santa Barbara itself reposes on alpine limestome rock. This last rock (alpenkalkstein), is in fact discovered on the eastern slope of the mountain near Acobamba and Sillacasa. It is still found at very considerable elevations, and is of a blueish grey, and traversed by a great number of small veins of calcareous spar. Ulloa observed there in 1761 petrified shells*, at a height of more

*We also found them on the ridge of the Andes, near Montan and Micuipampa; Geographie des Plantes, p. 127. See, as to the Pelasgic shells observed at great heights in Europe and America, Faujas de Saint-Fond, Essai de Geologie, T. ii. p. 61-69.

than 4300 metres*. M. de Nordenflycht also discovered pectinites and cardia in a bank of shells, between the villages of Acoria and Acobamba, near Huancavelica, at an elevation surpassing by more than 800 metres†, that of the bank of nummulites found by M. Ramond on the summit of Mont-Perdu.

The cinnabar by no means fills the whole quartz bed of the great mine of Santa Barbara; it forms particular strata; and sometimes it is found in small veins, which drag (se trainent) and unite in masses (stockwerke). Hence the metalliferous mass is only in general from 60 to 70 metres in breadth. Native mercury is extremely rare, but the cinnabar is accompanied with red iron ore, magnetic iron, galena, and pyrite; and the crevices are frequently variegated with sulphate of lime, calcareous spar, and fibrous alum (federalaun), with curvilinear parallel fibres. The metalliferous bed at great depths§, contains a good deal of orpiment, or red and yellow sulphuretted arsenic. This mixture formerly occasioned the

Particularly below the depth of 230 varas (629 feet. Trans.). The galena is found nearer the surface of the earth, and even 40 varas lower than the gallery of San Xavier.

death of many workmen, who wrought at the distillation of minerals of cinnabar mixed with orpiment, till the government took the resolution of prohibiting the carrying on the works of Cochapata, in which arsenic abounds the most. I suppose that the vapour called umpe, of which the alarming effects are described by Ulloa, is arsenical hydrogen gas; but it has been much more rarely felt than might be believed, from the accounts of the Spanish travellers.

The great mine of Santa Barbara is divided into three stories, (pertinencias) which bear the names of Brocal, Comedio, Cochapata. The depth of the mine is 349 varas; and its total length from north to south 536 varas. It is reckoned that 50 quintals of tolerably rich minerals, yield by distillation from 8 to 12 pounds of mercury. The mineral depository is worked by three galleries, viz: the Socabon de Ulloa, the Socabon de San Francisco Xavier, and the Socabon de Nuestra Señora de Belem, begun in 1615, and finished in 1642. The gallery cut by the astronomer Don Antonio Ulloa, who as governor of Huancavelica directed the works for some years, is only 75 varas in length; and its mouth is almost level with the great square of the town. It would require to be still prolonged 2000 varas, to traverse the pertinencia de Cochapata. It is the only gallery which

follows the direction of the metalliferous bed, for the two others were cut in the solid rock. The Socabon de Belem, the most useful of all these different works, is 625 varas in length, and cuts the mineral depository at the depth of 172 varas, below the summit of the mountain of Santa Barbara. The gallery of San Xavier, finished in 1732, is 112 varas above the Socabon of Belem. All these galleries which have cost immense sums, because they are more than five varas in breadth*, are merely for ventilation and interior conveyance; for the mine is absolutely free from water.

There has been extractedt from the great mine of Huancavelica, between 1570 and 1789, the sum of 1,040,452 quintals of mercury‡;

* More than 13 feet. Trans.

+ Noticias sobre la mina de Huancavelica, (M. S. note of

M. Mothes).

‡ 136,573,162 lb. Troy. Trans.