Arrieros; El Oro de Topago; San Juan Nepomuceno; Nuestra Señora del Monserrate del Zapote; Uriquillo; San Augustin; Nuestra Señora del Monserrate de Urique; Guarisamey; San Vicente; Guadalupe; Gavilanes; San Antonio de las Ventanas, San Dimas, San Joseph de Tayoltita; Cosiguiriachi; Rio de San Pedro ; Chihuahua el Viejo; San Juan de la Cieneguilla; Maguarichi; Caxurichi; San Jose del Parral*; Indehé; Los Sauces; Nuestra Señora de la Merced del Oro; Real de Todos Santos; San Francisco del Oro; Santa Barbara; San Pedro; Huejoquilla; Los Peñoles; La Cadena; Cuencamé, San Nicolas de Yervabuena; La Concepcion; Santa Maria de las Nieves; Chalchihuites; Santa Catalina; San Miguel del Mezquital; Nuestra Señora de los Dolores del Orito; San Juan del Rio; San Lucas; Panuco; Avinito; San Francisco de la Silla; Texamen; Nuestra Señora de Guadalupe de Texame; San Miguel de Coneto'; Sianori; Canelas; Las Mesas; Sabatinipa or Matabacas; Topia; San Rafael de las Flores; El Alacran; La Lagartija; San Ramon; Santiago de Mapimi, * On some proofs of my general map of New Spain, the name of Parral is confounded with that of the village of Valle San Bartolomé. The sign by which the chief seat of a provincial council of mines is indicated, points out the true position of Parral. VII. Intendancy of Sonora. From the 23° 15 to the 31° 20' of north lati'tude, and from the 107° 45' to the 113° 20′ of west longitude. Diputaciones de Mineria, or Districts. 26. Alamos. 27. Copala. 28. Cosala. 29. San Francisco Xavier de la Huerta. 31. Santissima Trinidad de Peña Blanca. Reales, or Places surrrounded by Mines: San Joseph de Copala; Real del Rosario; Plomosas; Santa Rosa or las Adjuntas; Apomas; San Nicolas de Panuco; Santa Rita; Trancito ; Charcas; Limon; Santa Rosa de las Lagunas; Tocusitita; Corpus; Reyes; Cosala; Palo Blanco; El Caxon; Santiago de los Caballeros ; San Antonio de Alisos; San Roque; Tabahueto; Norotal; Los Molinos; Surutato; Los Carcamos; San Juan Nepomuceno; Bacatopa; Loreto; Tenoriba; Aguacaliente; Monserrate; Sivirijoa; Baroyęca; Yecorato; Zataque ; Cerro Colorado; Los Alamos; Guadalupe; Rio Chico; La Concepcion de Haygame; Santissima Trinidad; La Ventana or Guadalupe; Saracachi; San Antonio de la Huerta; San : Francisco Xavier; Hostimuri; Quisuani; El Aguage; Higane; San Jose de Gracia; El Gabilan; El Populo; San Antonio; Todos Santos; El Carizal; Nacatabori; Racuach; San Ildefonso de Cieneguilla; San Lorenzo; Nacumini ; Cupisonora; Tetuachi; Basochuca; Nacosari; Bacamuchi; Cucurpe; Motepore. VIII. Intendancy af Valladolid. From the 18° 25′ to the 19° 50′ of north latitude, and from the 102° 15' to the 104° 50′ of west longitude. Diputaciones de Mineria, or Districts. 33. Angangueo. 34. Inguaran. 35. Zitaquaro. 36. Tlalpujahua. Reales, or Places surrounded by Mines: Angangueo; El Oro; Tlapaxahua; San Au gustin de Ozumatlan; Zitaquaro; Istapa; Los Santos Reyes; Santa Rito de Chirangangeo; El Zapote; Chachiltepec; Sanchiqueo; La Joya; Paquaro; Xerecuaro; Curucupaséo; Sinda; Inguaran; San Juan Guetamo; Ario; Santa Clara; Alvadeliste; San Nicolas Apupato; Rio del Oro; Axuchitlan; Santa Maria del Carmen del Sombrero; Favor; Chichindaro. IX. Intendancy of Oaxaca. From the 16° 35′ to the 17° 55′ of north latitude, and from the 98° 15' to the 100° 0' of west longitude. Diputaciones de Mineria, or Districts. Reales or Places surrounded by Mines: Zologa; Talea; Hueplotitlan; La Aurora de Ixtepexi; Villalta; Ixtlan; Betolatia; Huitepeque; Rio de San Antonio; Totomistla; San Pedro Nesicho; Santa Catalina; Lachateo; San Miguel Amatlan; Santa Maria Iavecia; San Mateo Capulalpa; San Miguel de las Peras. X. Intendancy of Puebla. From the 18° 15′ to the 20° 25′ of north latitude, and from the 99° 45′ to the 100° 50′ of west longitude. Scattered Mines: La Canada; Tulincingo; San Miguel Tenango; Zautla; Barrancas; Alatlanquetepec; Temetzla; Ixtacmaztitlan. XI. Intendancy of Vera Cruz. From the 20° 0' to the 21° 15′ of north latitude, and from the 99° 0' to the 101° 5' of west longitude. Scattered Mines: Zomelahuacan; Giliapa; San Antonio de Xacala. XII. Old California: Mine. Real de Santa Aná. Those who have studied the geological constitution of a mining country of great extent, know the difficulty of reducing to general ideas the observations made on a great variety of beds, and metalliferous veins. The naturalist may distinguish the relative antiquity of the different formations, and he is enabled to discover laws, in the stratification of rocks, in the identity of beds, and often even in the angles which they form, either with the horizon or the meridian of the place; but how can he recognize the laws which have determined the disposition of the metals in the bosom of the earth, the extent, the direction, and inclination of the veins, the nature of their mass, and their particular structure? How can he draw general results from the observation of a multitude of small phenomena, modified by causes of a purely local nature, and appearing to be the effects of an action of chemical affinities, confined to a very narrow space? These difficulties are increased when it happens, as in the mountains of Mexico, that the veins, |