Charles Martin Hall

Aluminium was once priced like silver because nobody could separate it cheaply. Hall, a young chemistry graduate from Oberlin College, worked out in 1886, in a woodshed with his sister Julia's help, how to do it by passing current through alumina dissolved in molten cryolite; Paul Héroult in France found the same method independently. Backed by Pittsburgh investors led by Alfred Hunt, Hall's process became the Pittsburgh Reduction Company, later Alcoa, and the price collapsed.