238 REPORT OF NATIONAL MUSEUM, 1899. 



cessation of the spring-action, surface-creep of the residual mantle from the higher por- 

 tions of the ridges covered the deposits to varying depths, as they are found at present. 

 A small portion of the ferrous sulphate was oxidized and precipitated along with 

 the bauxite, but the greater part was carried some distance from the springs and 

 slowly oxidized, forming the widespread deposits of limonite in this region. 



ffggg. The better known use of bauxite is as an ore of aluminum, 



for which purpose it lies beyond the scope of the present work. It 

 may, however, be well to state that before the aluminum can be satis- 

 factorily extracted the ore is purified by chemical processes. The 

 principal use is for the manufacture of alums and other aluminum 

 salts such as are used in the manufacture of baking powders and dyes. 

 It is believed that the mineral, owing to its highly refractive qualities, 

 will in the near future be utilized in the manufacture of fire brick and 

 crucibles. An alumino-ferric cake, a by-product obtained in the puri- 

 fying process, is claimed as of value for sanitary and deodorizing 

 purposes. The price of the crude ore varies greatly, according to 

 purity. The average price for the past few years has been about $5 



a ton. 



BIBLIOGKAPHY OF CRYOLITE AND BAUXITE. 



PAUL QUALE. Account of the Cryolite of Greenland. 



Annual Report of the Smithsonian Institution, 1866, p. 398. 



M. H. COQUAND. Sur les Bauxites de la chaine des Alpines (Bouches-du-Rhone) et 

 leur age geologique. 



Bulletin de la Socie"te Geologique de France, 2d ser., XXVIII, 1870-71, pp. 

 98-115. 

 EDWARD NICHOLS. An Aluminum Ore. 



Transactions of the American Institute of Mining Engineers, XVI, 1887, p. 905. 

 P. JOHNSTRUP. Sur le Gisement de la Kryolithe au Greenland. 



Bulletin de la Soci<te Mineralogie of France, II, 1888, p. 167. 

 M. AUGE. Note sur la Bauxite, son origine, son age et son importance geologique. 



Bulletin de la Societe" Geologique de France, 3d ser., XVI, 1888, p. 345. 

 STAINSLAS MEUNIER. Response a des observations de M. Aug6 et de M. A. de Gros- 

 souvre sur Phistoire de la Bauxite et des Minerals Side"rolithiques. 



Bulletin de la Societe Geologique de France, 3d ser., XVII, 1889, p. 64. 

 R. L. PACKARD. Aluminum. 



Mineral Resources of the United States, 1891, p. 147. 



This paper contains numerous references to which the present compiler has 

 not had access. 

 HENRY MCCALLEY. Bauxite. 



The Mineral Industry, II, 1893, p. 57. 

 Bauxite Mining. 



Science, XXIII, 1894, p. 29. 



C. WILLARD HAYES. The Geological Relations of the Southern Appalachian Bauxite 

 Deposits. 



Transactions of the American Institute of Mining Engineers, XXIV, 1894, p. 243. 

 W. P. BLAKE. Alunogen and Bauxite of New Mexico. 



Transactions of the American Institute of Mining Engineers, XXIV, 1894, p. 571. 

 FRANCIS LAUR. The Bauxites. A Study of a new Mineralogical Family. 



Transactions of the American Institute of Mining Engineers, XXIV, 1894, p. 234. 

 On Bauxite. 



Minutes of the Proceedings of the Institute Civil Eng., CXX, 1894-1895, pt. 2, 

 p. 442. 



