440 JOSEPH STRUTHERS 



plateau of Quercy, in the department of Lot, and in 1870 

 the deposits in the Lot-et-Garonne, Tarn-et-Garonne, and 

 Aveyron (known as the Bordeaux phosphates) were mined and 

 the product sold to fertilizer manufacturers. In Spain the 

 mining of phosphate rock began at Logrosan, province of Es- 

 tremadura, about the year 1855, followed in 1860, by the ex- 

 ploitation of the deposits near Caseres, the latter district yield- 

 ing a considerable quantity annually until 1875. In Norway 

 phosphate deposits were mined at Kragero, in 1854, and at 

 Oedergarten, in 1874. In Germany the Nassau phosphate 

 deposits were discovered in 1864 and the mining of the rock 

 commenced at once. In recent years the competition in the 

 world's markets, of higher grade and purer phosphates from 

 other countries has caused the cessation of the exports of rock 

 from the Lahn mines, the material of which contains a large 

 percentage of iron and aluminum oxides. In a few of the 

 islands of the West Indies, notably Navassa and Sombrero, 

 prior to 1865 phosphate deposits had been opened and the 

 product shipped to the United States and the United King- 

 dom. 



In the United States deposits were first worked in South 

 Carolina in 1867. From 1867 to 1877 there was a great ad- 

 vance in the world's production of phosphate rock. In 1873 

 Belgium began contributing to the world's supply from the 

 deposits near Mons, and France increased its production very 

 largely. In 1880 the islands of Curacoa and Oruba, in the 

 Dutch West Indies, supplemented the output of high grade 

 phosphates and shipped an average of 10, 000 tons for the year. 



In the decade 1880 to 1890 the sources of supply of phos- 

 phate rock altered very considerably. At the end of this period 

 Spain, which in 1882 and 1883 shipped 100,000 tons to the 

 United Kingdom, practically ceased to export. In France 

 the old sources of supply had been replaced to a large extent 

 by the newer fields in the Somme and other departments in 

 the north. Belgium had assumed an important place, pro- 

 ducing about 150,000 tons of phosphate from the mines at 

 Mons alone. In the United States the South Carolina de- 

 posits had been developed to a very large extent and Florida 

 had begun to contribute appreciably to the supply. 



