=Peruvian Deposits.=--The largest deposits of vanadium in the world, and the most important, were until recently controlled by the American Vanadium Co. of Pittsburgh, Pennsylvania, which in 1919 was absorbed by the Vanadium Products Corporation, allied to the Bethlehem Steel Corporation. These deposits are at Minasragra, Peru, 20 miles from Cerro de Pasco. The area lies along the western limit of a broad anticline in Juratrias and Cretaceous rocks. A section shows the series in this locality to be composed of green shales, thin beds of limestone, and red shales. Vanadium is found only in the red shales. The deposit proper appears to be a lens-shaped mass, 28 feet wide and 350 feet long. The ore contains several minerals. The mineral that constitutes the large portion of the deposit is called “quisqueite”; it is a black carbonaceous substance containing sulphur. There is also a lesser quantity of a coke-like material. Neither of these contains vanadium. The vanadium is mostly at the southern end of the ore body, and to a depth of 20 feet is largely in the form of red calcium vanadate, which is brighter colored then the calcium vanadate in Colorado and Utah, and carries as much as 50 per cent. vanadium oxide. It occurs in small pockets and fills the cracks and fissures in a fine shale. Below this shale is the “mother lode,” which is 9 to 30 feet thick, extends along the greater length of the deposit, and carries as high as 10 per cent. vanadium oxide and nearly as much sulphur. On the east and south sides, below the “mother lode,” is a hard blue-black vanadium shale, carrying as much as 13 per cent. vanadium oxide and 4 to 5 per cent. sulphur. Patronite, the main vanadium mineral, is greenish black and contains 19 to 24.8 per cent. vanadium oxide and in places 50 to 55 per cent. of combined sulphur. The patronite originally almost reached the surface and is most abundant in the north half of the lens. The whole ore body is almost completely inclosed by porphyry dikes and contains two or three intrusions. These deposits are controlled by the American Vanadium Co., and its successor, the Vanadium Products Corporation, through a concession from the Peruvian government. They are large, but are by no means inexhaustible, and as they are entirely local they are not likely to be duplicated. No similar deposits are known, either in Peru or in any other part of the world. In 1917 the American Vanadium Co. treated 5,236 gross tons of ore, from which it extracted 2,122,005 pounds of vanadic acid. From this vanadic acid the company manufactured 4,925,014 pounds of ferrovanadium. The company did not buy any ore in this country, but relied entirely upon its Peruvian production.