If the ingot was so rich in gold that it contained more than one-half of its weight of that metal, the duty of assaying rose to four reals, or 2s. 3d. per mark. The produce of the Mexican mines would be much more abundant, and be attended with much less expense, were the skill of the miners equal to those of Europe. The most obvious defects in the management of the mines have hitherto been the clumsy, imperfect, and expensive manner of clearing them from water,-the want of arrangement in the disposition of the galleries, and the absence of lateral communications, which add to the uncertainty, and increase prodigiously the expense of working the mines. No plan of the galleries was formed; and no contrivances were used for abridging labour, and facilitating the transport of materials. When new works were undertaken, they were often begun without capital, and always conducted on a scale too large and expensive. Yet from what has been stated respecting the progressive increase of the Mexican mines, notwithstanding the comparative want of mineralogical skill, the waste of mercury, and ignorance of machinery displayed in the mining operations, it is easy to infer that the mineral produce of New Spain has not yet obtained its maximum. Under a better government, and a more industrious population, the produce of New Spain would exceed that of all America put together, in Humboldt's opinion. It is believed that New Spain produces only one-third of the precious metals which it would do under happier political circumstances. This opinion was formally announced by the deputies of miners, in a petition presented to the king in 1772; and now that the Mexicans have succeeded in establishing their independence, there is little doubt but that, freed from the paralyzing influence of the mother-country, a great increase of mineral produce will be the result of the unfettered energies of the colonists, aided by European skill and capital, which has already begun to flow in this direction, many millions of British capital having been invested in these mines in 1825 and 1826. As to the number of persons employed in the mines, it is far less than is commonly supposed. The whole number employed in the miningdistricts of Guanaxuato did not exceed, when Humboldt wrote, 5,000 persons of every description; and all the miners in New Spain, under the various appellations of barenadores, taeneros, tenateros, and bareteros, was not above 30,000, or 1-200th of all the population. The labour of the mines is perfectly free, and no trace of the mila, or barbarous law which compelled the Indians to remove from their homes to labour in the mines, remains, though Dr Robertson has advanced the contrary. It is absolutely false, (says Humboldt,) also, that galley-slaves are sent from Spain to America, to labour in the mines. The Mexican miner is the best paid of all miners, gaining at the least from £1 2s. 6d. to £1 4s. 9d. weekly, while those of the common labourer do not exceed a dollar and a half. The tenateros, or persons who carry the ore on their backs, from the place where it is dug out of the mine to the place where it is collected in heaps, receive 4s. 10d. per day, of six hours labour. The labour, indeed, is very severe, as they are loaded with from 225 to 350 lbs. weight of mineral, with which they ascend eight or ten times successively, without halting, stairs of 1,800 steps; but the appearance of these robust Indians completely refutes the assertions of Raynal, Pauw, and a number of other philosophical dreamers, who have declaimed so pathetically upon the degeneracy of the human species in the torrid zone. The most un healthy part of the subterraneous labour is that of the barenadores, or blowers, who explode the rock with powder. These rarely pass the age of 35, if from a thirst of gain they continue their labour for the whole week. The art of amalgamation was introduced into Mexico by Medina, a miner of Pachuca, and various methods have been successively introduced to improve it. They are, however, far behind the miners of Europe in the science of amalgamation; and the waste of mercury is immense, being in general from 12 to 14 ounces of mercury for every mark of silver which is extracted, or eight times more in proportion than what is consumed in Saxony, which is only from 1 to 12 ounces to the mark of silver. There the silver is extracted from the ore in 24 hours, whereas in New Spain from 60 to 150 days are employed in the same process. The annual consumption of New Spain, when Humboldt wrote, was 16,000 quintals, or 2,100,212 lbs. troy of mercury, the price of which in New Spain was £155,000 sterling. Almaden in Spain alone furnished, in 1802, 20,000 quintals of mercury to the American mines; but as the mines of Almaden could not, in ordinary cases, supply all the mercury requisite for amalgamation, the residue was made up by the mines of Idria, in Carniola. In 1784, a contract was made with the emperor of Austria, by the court of Spain, by which the former was to furnish mercury at the rate of 52 dollars per quintal. Before 1770, when the working was far from being so considerable as at present, the mercury was wholly obtained from Huancavilica, in Peru; and the German quicksilver was only introduced into Mexico after the falling in of the mine of Huancavilica, and the inundation of the mine of Almaden, in Spain. From 1762 to 1781, the quantity of mercury destroyed in the amalgamation of the Mexican mineral amounted to 191,405 quintals, or 25,124,200 lbs. troy, the value of which, in Mexico, was upwards of £2,400,000 sterling. The working of the mines is regulated by the price and quantity of the quicksilver. In 1590, its price was 187 dollars per quintal; but in 1750, it was distributed by the court of Madrid, to the miners, at the rate of 82 dollars per quintal. Between 1767 and 1776, its price was at 62 dollars per quintal. In 1777, through the influence of Galvez, the viceroy of Mexico, and to whom America is indebted for the partial enlargement of her trade, the price of mercury was reduced to 41 piastres, 2 reals per quintal of Spanish mercury; and 63 dollars per quintal of German mercury. An attempt was made to procure mercury from China, in 1782, but it miscarried. Chinese mercury procured at Canton was very small, of impure quality, containing a great deal of lead, and its price 80 dollars per quintal. Humboldt is of opinion, that there are mines of cinnabar in New Spain and New Granada, as well as in Peru, sufficient to answer the home-demand. Only two mines, however, of cinnabar were wrought in New Spain while Humboldt was there, and the produce was but small. It is impossible to judge what quantity of mercury the various mines enumerated by him are capable of yielding, till they are more carefully wrought, or more rigidly examined. It is probable that, if all the mines were wrought at once, and if a more economical use of mercury in amalgamating were adopted, in proportion as chemical and mineralogical science should advance in Mexico, that the colonists will be rendered wholly independent of Europe for the supply of mercury. The Gold Mines.] The Mexican gold is for the most part obtained from alluvious grounds, by means of washing. These grounds are common in the state of Sonora. In the plain of Cineguilla, grains of gold of such a size were found, at the depth of 19 inches from the surface, that some of them weighed nine marks each, equivalent in value to £285 8s. sterling. In the mines of Yecorata, in Cinaloa, a piece of gold was found, which weighed 16 marks, 4 ounces, and 4 ochavas, value £540 sterling, which was sent to the royal cabinet at Madrid. Pepitas of pure gold have been found in Pimeria Alta, in 31° N. lat., weighing from 5 lbs. 2 oz. 2 dr. 2 scr. 8 gr. to 8 lbs. 4 dr. 12 gr. But the frequent incursions of the warlike savages, the excessive high price of provisions in this uncultivated country, and the want of water necessary for working, are all great obstacles to the extraction of gold in this place. Another, but the smallest portion of Mexican gold, is extracted from the veins which intersect the mountains of primitive rock, particularly in the intendancy of Oaxaca, either in gniess, or in micaceous schist. This last rock is very rich in gold, in the celebrated mines of Rio San Antonio. These veins, of which the gangue is milky quartz, are more than 1 foot 6 inches thick, but their rich. ness is very unequal. The same metal is also to be found, either pure or mixed with silver ore, in the greatest number of veins which have been wrought in Mexico, and there is scarcely a single silver mine which does not contain some gold. Native gold is also frequently found crystallized in a reticulated form, in the silver mines of Villalpando and Rayas, near Guanaxuato; in those of Sombrero, in the intendancy of Valladolid; Guarisamey, to the west of Durango; and Mesquital, in Guadalajara. The gold of Mesquital is deemed to be the purest, as being least alloyed with silver, iron, and copper. The principal vein in the mine of Villalpando, is intersected by a great number of small rotten veins of exceeding richness. The argillaceous or clayey slime with which these veins are filled, contain so great a quantity of gold, disseminated in impalpable parcels, that the miners are compelled, when they leave the mine nearly naked, to bathe themselves in large vessels, to prevent any of the auriferous clay from being carried off by them on their bodies. Inferior Minerals.] Having finished the account of the precious metals, we now come to what are called the common metals. Copper is found in a native state, in the mines of Ingara, to the S. of the Volcan de Jorullo; and at San Juan Guetamo, in the province of New Mexico. These last are situated in N. lat. 34°, in a mountain belonging to the Topian chain, to the W. of the Rio del Norte. The copper produced here amounts to 20,000 mule loads annually, furnishing that article for the manufactures of nearly all the internal provinces. The intendancy of Guanaxuato produced, in 1802, nearly 9,200 arrobas, or 230,000 lbs. of copper, and 400 arrobas, or 10,000 lbs. of tin. Tin is also pretty abundant in the internal provinces, where a number of valuable mines of this mineral are situated in the vicinity of Durango. The iron mines are very abundant in the intendancies of Valladolid, Zacatecas, and Guanaxuato, but especially in the internal provinces. Lead abounds in the calcareous mountains in the north-east of the viceroyalty, especially in the district of Zimapan, near the Real de Cardonal and Lomo del Toro; near Linares, in the kingdom of new Leon, and in the province of Santander. At Lomo del Toro, masses of galena are wrought, of which some nests have yielded, in a short space of time, according to Soninschmidt, more than 124 quintals of lead. Zinc is found under the form of brown and black blende, in the veins of Ramos, Sombrerete, Zacatecas, and Tasco. Antimony is common to Catorce and Los Pozuelos. Arsenic is found among the minerals of Zimapan, combined with sulphur, like orpiment. Cobalt has never yet been discovered; and manganese is much less abundant in equinoctial America, than in the temperate climates of the old world. About 100 miles to the south of Chihuahua, an entire mountain of loadstone, or magnetic iron, has been lately discovered. The strata are as regular as those of limestone. That most useful of all minerals, coal, is very rare in New Spain. It has hitherto been only discovered in New Mexico; but it is, however, probable, that it may be found in the secondary lands extending to the north and north-west of the Rio Colorado of Texas, as well as in the plains of the latter, and those of San Louis Potosi. There is already a coal mine near the source of the Sabine river. In general, coal and rock-salt abound to the west of the dividing ridge that separates the waters flowing into the Mississippi, (Missouri,) and the gulf of Mexico, from those that descend to the gulf of California. In the whole inhabited part of New Spain, there is no rock-salt equal to that of Zepaguera, in New Granada, or of Wielieczka, in Poland. The muriate of soda is no where disseminated in masses or banks of considerable volume, and is merely disseminated in the clayey lands which surmount the ridge of the Cordilleras: so that, in this respect, the table land of Mexico resembles that of Tibet or Tartary. The most abundant salt-mine of Mexico, is the lake of the Penon Blanco, in San Louis Potosi, of which the bottom is a bed of clay, containing from 12 to 13 per cent. of the muriate of soda. Were it not, however, for its use in the amalgamation of silver minerals, the consumption of salt would be very inconsiderable in Mexico, the Indians preferring their old custom of seasoning meat with chili, or pimento. The Indian consumption of salt cannot be estimated at much more than half a kilograme per head, or only one-twelfth of that in Europe. These liquid minerals, amber and asphalt, likewise occur in New Spain. Among the precious stones, a few diamonds are found, with amethysts and turquoises, but the list is imperfect, and perhaps erroneous. The mountains produce jasper, marble, alabaster, magnets, steatite, jad, and talc. The fine marble of Puebla is found within a few leagues of that city. One kind, that of Tecali, is translucent, like the alabaster of Volterra, and the phengites of the ancients. Near Santa Fé, a stratum of talc is found in some of the mountains, so large and flexible as to admit of being subdivided into thin cakes, of which the greatest proportion of the houses in Santa Fé, and all the villages to the north, have their window lights made. Among the most singular fossils, are the bones of the mammoth, mentioned by Estalla. On digging the foundation of the convent of Guadaloupe, these bones were found lying upon sand, in different parts, at the depth of 12 feet. Similar bones were found in the hill Tepeyac. A tusk found at Guadaloupe measured ten feet in length. Basaltic rocks.] The valley of Mexico is separated from the basin of Totonilco el Grande by a chain of porphyritic mountains, the highest summit of which, the peak of the Xacal, rises to an elevation of 10,248 feet above the level of the sea. These " enormous columns of trappean porphyry," crowned with pines and oaks, are of a very picturesque character: it is from them that the ancient Mexicans obtained the itzli, or obsidian, of which they formed their sharp instruments. This porphyritic formation serves for base to the porous amygdaloid which surrounds the lakes of Tezcuco, Zumpango, and San Christobal. To the north-east of the district of Real del Monte, it is concealed under the columnar basalt of Regla, and further on, in the valley of Totonilco, under beds of secondary formation. The Alpine limestone, of a greyish blue, in which is the famous cavern of Dante, called "the pierced mountain," or "the bridge of the Mother of God," (puente de la Madre de Dios,) appears to repose immediately on the porphyry of Moran. The basaltic rocks and cascade of Regla form one of the most remarkable natural curiosities in Mexico. "The cascade of Regla," says Hum-boldt, "is situated at a distance of 25 leagues N.E. from Mexico, between the celebrated mines of Real del Monte and the thermal waters of Totonilco. A small river, which moves the wheel of the amalgamation-mill at Regla, forces its way across the groupes of basaltic columns. The sheet of water that rushes down is considerable, but the fall is not above 25 feet. The surrounding rocks, (which remind us of the cave of Fingal at Staffa, in the Hebrides,) the contrasts of vegetation, the wild appearance, and the solitude of the place, render this small cascade extremely picturesque. On both sides of the ravine, the basaltic columns rise to more than 100 feet in height, and on them grow tufts of cactus and yucca filamentosa. The prisms have generally five or six sides, and are sometimes as much as from three to four feet in breadth: several present very regular articulations. Each column has a cylindrical nucleus, of a denser mass than the surrounding parts: these nuclei are as it were enchased in the prisms, which, in their horizontal fracture, offer very remarkable convexities. This structure, which is also found in the basalts of Fairhead, is shown in the foreground of the drawing, towards the left. The greater part of the columns are perpendicular: though some very near the cascade have an inclination of 45° towards the east, and further on, there are others horizontal. Each groupe, at the time of its formation, appears to have followed particular attractions. The mass of these basalts is very homogeneous. The prisms repose on a bed of clay, under which is again found basalt, superposed on the porphyry of Real del Monte. The whole of this basaltic region is 6,500 feet above the level of the ocean." CHAP. V.-POPULATION AND NATIVE TRIBES. WHENCE, and in what way the American continent was originally peopled,- -are questions which have never yet been satisfactorily answered. If the geological constitution of America be attentively examined, the opinion that it is a continent more recently formed than the rest of the globe must be abandoned. The same succession of stony strata are found no less in the new world than in the old world. At a height superior to Mont Blanc, petrified sea-shells are found on the summits of the Andes. The fossil bones of elephants are spread over the equinoctial regions of a continent where living elephants do not exist; and these bones are not found merely in low plains, but in the coldest and most elevated regions of the Cordilleras; here, then, as well as in the old world, generations of animals, long extinct, have preceded those which now exist on the surface of the earth. The comparative thinness of the population of America is no proof that it has been but recently peopled; for the regions of Central Asia are as thinly peopled as the savannahs of New Mexico and Paraguay. The fact is, that the problem of the first population of most countries, is nearly as difficult to solve as that of America; and for the same plain rea |