16 
ALUMINIUM AND THE CLEVELAND KAOLIN. 
of late years detracted from its successful use. This mineral 
occurs most extensively at Evigtock, in West Greenland, and is 
shipped in quantity to Europe and the United States, where it 
is used for making aluminium, soda, soda and alumina salts, 
and — in Pennsylvania — for the manfacture of a white glass 
resembling porcelain in appearance. In April of the present 
year the powdered kryolite was quoted in the rnarket at £20 per 
ton for small quantities, a price which would of course be much 
reduced for pai*cels in bulk of unassorted mineral {vide 
“ Entfineerin^j and 2iininf( JoiirnaL”) 
Bauxite — a name derived from Beaux, near Arles, in 
France, where large deposits of the mineral occur — is then the sub- 
stance whence aluminium is now principally derived. In addi- 
tion to the above-mentioned locality in France it is now known 
that there are vast deposits of it in Ireland, and that it also 
exists in considerable quantities in the States of the American 
Union — North Carolina and Georgia. The grey shale, quoted 
by John D. Hennessy in the Courier^ 27th June, 1892, as being 
sold on the Continent of Europe at £2 17s. per ton, is probably 
the popular name in commercial circles for bauxite. It contains 
no less than from 60 to 80 per cent, of its weight of alumina, 
almost the whole of which is free when its water of constitution is 
not taken into consideration. The following is the average compo- 
sition of the mineral as shown by chemical analysis : — Alumina, 
64*24 ; silica, 6*29 ; oxide of iron, 2*40 ; lime, 0*55 ; magnesia, 
0*38 ; soda, 0*20 ; potash, 0*46 ; water, 25*74 ; total, 100*26. 
In the manufacture of aluminium from bauxite, the 
alumina is first separated chemically from iron, silica, and other 
impurities. It is then washed, dried, and calcined at a red heat 
for a considerable time. There are several methods available 
for treating the alumina for aluminium. The Pittsburg Reduc- 
ing Company reduce the metal from the prepared oxide (alumina) 
by electrolysis, the aluminium being held in solution by a 
molten fluoride bath, which is itself not decomposed by the 
electric current. 
The Cleveland deposits being, as we have seen, of no value 
as sources for either alumina or aluminium, it remains to con- 
