I. An inland department of Peru, occupying a portion of the valley bordered by the Eastern and "Western Cordilleras S. E. of the department of Lima. The surface is intersected by numerous hills, and watered by the Jauja and other rivers, and numerous lakes. The climate is mostly very cold, and the soil rather inferior to that of other parts of the republic. There being no forests, wood is scarce, and the chief combustible used is a species of grass called ichu. Gold is found, silver is abundant, and there is some copper; but the principal mineral product is mercury, especially that from the mine in the Cerro de Santa Barbara, discovered in 1563, the mean annual yield of which for 200 years was from 400,000 to 600,000 lbs. Large numbers of cattle, sheep, and llamas are reared, and wool of excellent quality is exported. II. A city, capital of the department, and of a province of the same name, 150 m. S. E. of Lima; pop. about 8,000. The streets are regular, and the houses solidly constructed of stone; several stone bridges cross the streams intersecting the town. Owing to the elevation, 12,670 ft. above the sea, the climate is very cold, and the town is Exposed to fierce tempests, thunder, hail, and frost. Husbandry, cattle rearing, and mining are the chief occupations.

In the immediate vicinity are numerous mercury furnaces; and excellent colors are extracted from a peculiar species of metalliferous clay which abounds in the neighborhood.