ELECTROCHEMISTRY 153 



Aluminium: The most useful of the light metals; an 

 element more abundant in nature than iron, yet which 

 costs by chemical methods at least $1.00 per pound to pro- 

 duce; electrochemistry enables the makers to sell it at a 

 profit at $0.25 per pound. This is probably the. most useful 

 metal given to the world by electrochemistry. Although 

 the French chemist Deville obtained it by an electrolytic 

 method in 1855, yet he had only the battery as a source of 

 electric current, and the process was too costly. This very 

 city of Pittsburg was the real cradle of the electrolytic 

 manufacture of aluminium, when, in 1889, Mr. Chas. M. 

 Hall, with the financial assistance of the Mellons and the 

 business assistance of Capt. A. E. Hunt, commenced to 

 work his process up at Thirty-third Street on the "West 

 Side." The principle of the process is here again one of 

 beautiful simplicity when it is once made known. Alu- 

 minium oxide, abundant in nature, is infusible in ordinary 

 furnaces, but easily melts and dissolves, like sugar in 

 water, in certain very stable and liquid fused salts double 

 fluorides of aluminium and the alkali metals. On passing 

 the electric current through this bath, the dissolved alu- 

 minium oxide is decomposed, appearing at the two elec- 

 trodes as aluminium and oxygen respectively. When all the 

 oxide is thus broken up, more is added, and the operation 

 continues. One of the most difficult problems of ordinary 

 chemistry is thus simply, neatly and effectively solved by 

 electrochemistry. The lower cost of power at Niagara 

 Palls drew the industry away from Pittsburg, in 1893, and 

 it is now run on an immense scale at several places where 

 water-power is cheap and abundant. Mechanical power 

 is, however, being produced cheaper every year; gas 

 engines have halved the cost of such power, steam turbines 

 on exhaust steam may even do better ; there is no inherent 

 impossibility in the return of the aluminium industry to 

 the Pittsburg district. Many other factors besides cost of 

 power bear on the question ; cost of labor, abundance of 

 labor, cost of carbon, coal for heating, various supplies, 



