ELECTROCHEMISTRY — RICHARDS. 171 



Magnesium. — This is a wonderfully light metal, whose chief use is 

 in flashlight powders. Its compounds are abundant in nature, but 

 its manufacture by any other than the electrolytic method is almost 

 impracticable. The operation consists in simply passing the decom- 

 posing current through a fused magnesium salt — a chloride of 

 magnesium and potassium found in abundance in Germany. 



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 per pound to produce; 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 Pittsburgh was the real 

 cradle of the electrolytic manufacture of aluminium, when in 1889 

 Mr. Charles 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. Aluminium 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 flourides of alu- 

 minium and the alkali metals. On passing the electric current 

 through this bath, the dissolved aluminium oxide is decomposed, 

 appearing at the two electrodes as aluminium and oxygen, respec- 

 tively. 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 Falls drew the 

 industry away from Pittsburgh 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 Pitts- 

 burgh 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, railroad freights, nearness to the con- 

 sumers, and many other considerations must be taken into account. 

 Aluminium is certainly destined to become the most important metal 

 next to iron and steel, and, as far as one can now foresee, will always 

 be produced electrochemically. To have accomplished the estab- 

 lishment of this one single industry would of itself have proved the 

 usefulness of electrical methods and their importance to chemistry 

 and metallurgy. ♦ 



