to the passage of the current offered by the cryolite transforms into heat sufficient electrical energy to fuse the cryolite. Into the fused cryolite is poured calcined and purified bauxite in powdered form. The oxygen of the purified bauxite combines with the carbon of the anodes or positive poles of the electrolytic cell to form carbon monoxide and carbon dioxide gases and the aluminum is withdrawn in an almost chemically pure state. Since the cryolite serves merely as a solvent for the bauxite from which the aluminum is obtained and is unaffected by the electric current, the reduction of bauxite is continued indefinitely by pouring into the reducing pot enough bauxite to supply the place of that reduced.
Another electrolytic process in use at Niagara Falls is the production of caustic soda. The demand for caustic soda in many industries such as soap-making and paper-making is so great that an inexpensive way of producing this important alkali is imperative. The process is