(* The breadth of this immense chain is a phenomenon well worthy of attention. The Swiss Alps extend, in the Grisons and in the Tyrol, to a breadth of 36 and 40 leagues, both in the meridians of the lake at Como, the canton of Appenzell, and in the meridian of Bassano and Tegernsee.) It is only in the knots of the mountains, that is where the Cordillera is swelled by side-groups or divided into several chains nearly parallel, and reuniting at intervals, for instance, on the south of the lake of Titicaca, that it is more than 100 to 120 leagues broad, in a direction perpendicular to its axis. The Andes of South America bound the plains of the Orinoco, the Amazon, and the Rio de la Plata, on the west, like a rocky wall raised across a crevice 1300 leagues long, and stretching from south to north. This upheaved part (if I may be permitted to use an expression founded on a geological hypothesis) comprises a surface of 58,900 square leagues, between the parallel of Cape Pilesar and the northern Choco. To form an idea of the variety of rocks which this space may furnish for the observation of the traveller, we must recollect that the Pyrenees, according to the observations of M. Charpentier, occupy only 768 square sea leagues. The name of Andes in the Quichua language (which wants the consonants d, f, and g) Antis, or Ante, appears to me to be derived from the Peruvian word anta, signifying copper or metal in general. Anta chacra signifies mine of copper; antacuri, copper mixed with gold; and puca anta, copper, or red metal. As the group of the Altai mountains* takes its name from the Turkish word altor or altyn (* Klaproth. Asia polyglotta page 211. It appears to me less probable that the tribe of the Antis gave its name to the mountains of Peru.), in the same manner the Cordilleras may have been termed "Copper-country," or Anti-suyu, on account of the abundance of that metal, which the Peruvians employed for their tools. The Inca Garcilasso, who was the son of a Peruvian princess, and who wrote the history of his native country in the first years of the conquest, gives no etymology of the name of the Andes. He only opposes Anti-suyu, or the region of summits covered with eternal snow (ritiseca), to the plains or Yuncas, that is, to the lower region of Peru. The etymology of the name of the largest mountain chain of the globe cannot be devoid of interest to the mineralogic geographer.