13 



y Calvo of Chihuahua, and southwards to Oaxaca, thus cutting the 

 main axis of upheaval at an angle of 45, will intersect probably the 

 richest known argentiferous region in the whole world. 



Of other minerals the most important are copper, found in a pure 

 state near the city of Guanajuato, and associated with gold in Chihua- 

 hua, Sonora, Guerrero, Jalisco, Michoacan, and elsewhere ; iron in 

 immense masses in Michoacan and Jalisco, and in Durango, where the 

 Cerro del Mercado is a solid mountain of magnetic iron ore ; lead 

 associated with silver, chiefly in Oaxaca ; tin in Michoacan and Jalisco ; 

 sulphur in many craters ; platinum, recently found in Hidalgo ; cin- 

 nabar, also recently found in Morelos and Guerrero ; " steppe salt " in 

 the sandy districts of the north ; " bitter salt " at Tepeyac and many 

 other places ; coal at various points ; bismuth in many parts ; marble, 

 alabaster, gypsum, and rock-salt in great abundance throughout the 

 plateaus and the sierras. 



MINING. 



Mexico is, perhaps, the richest mining country in the world, and 

 the production of silver notwithstanding the imperfect methods 

 and other drawbacks with which it has contended represents over 

 one-third of the product of the world, according to official statis- 

 tics. Almost all the mountains of Mexico are of the metalliferous 

 character, but those which seem richest in mining deposits are the 

 western cordillera, extending from the State of Oaxaca to Sonora, a 

 distance of about 1600 miles from northwest to southeast. 



Humboldt gave as his opinion that Mexico would be " the treasure 

 house of the world." Subsequent history has, in a great measure, con- 

 firmed the opinion of the great savant of his time. Still a more con- 

 servative authority has quite lately asserted that only one-tenth of 

 the mining resources of Mexico is known. This last estimate, I am 

 sure, is inside rather than outside of the facts. Mexico has always 

 been considered the great silver producer, and, considering her area, 

 and taking the century as a measure, she is the greatest silver producer 

 of the world. 



Silver. The central group of mines in the three mining districts of 

 Guanajuato, Zacatecas, and Catorce, in the States of Guanajuato, Zaca- 

 tecas and San Luis Potosi, which have yielded more than half of all 

 the silver heretofore found in Mexico, lies between 21 and 24 30' N., 

 within an area of about 13,000 square miles. Here the Veta Madre 

 lode of Guanajuato alone produced $252,000,000 between 1556 and 

 1803. 



In the beginning of this century Humboldt found two Guanajuato 

 mines the famous " Conde de Valenciana " and the " Marques de 

 Rayas " producing annually 550,000 marks, 4,400,000 ounces, of silver, 



