THE BAUXITE DEPOSITS OF ARKANSAS 283 



also important to observe that bauxite when exposed to intense 

 heat is converted into a solid mass of emery of such extreme 

 hardness that it can hardly be touched by steel tools, and is capa- 

 ble of resisting mechanical as well as the calorific and chemical 

 actions to which it is exposed. 



"The bauxite used in the above mentioned lining was of the 

 following composition : 



AI2O3 - - - 53.62 



FczOs - - - - 42.26 

 SiOa - - - - 4.12" 



Speaking of the value of bauxite as a refractory material Pro- 

 fessor Thomas Egleston of the Columbia School of Mines says 

 that it " lasts five or six times as long as the best Stourbridge 

 bricks. Nothing has yet- been found which resists the corrosive 

 action of basic slags so well."^ 



In a letter to the author regarding bauxite as a refractory 

 material Professor Egleston writes : 



"If the material is pure there would be a very large demand 

 for it. With the introduction of basic processes, the demand 

 for basic lining has increased steadily, but on account of the 

 uncertainty of the composition of bauxite, it is being very gen- 

 erally replaced by carbonate of magnesia, which is found in several 

 localities in Europe and is imported both to England and this 

 country." 



The results of several analyses of Aakansas bauxites were 

 sent Professor Egleston when he wrote : 



"The subject is a very interesting one and may be of great 

 value to the state if it should prove that any of these are alumi- 

 nates. In some of them I fear there is too much silica, but in 

 any case I think valuable fire bricks could be made of them. I 

 have often tried to interest the fire-brick people in the new proc- 

 cesses for the manufacture of these bricks which have been 

 developed within the past ten or fifteen years in Europe, and in 

 the hope of so doing have published several articles on the sub- 

 ject, but the manufacturers have been generally unwilling to 



'Transactions Am. Inst. M. E., Vol. IV., 261-2. 



