"When heated, hydrogen will combine with the oxygen of many oxides, forming water (steam) and the metal, thus: Copper oxide + hydrogen yields copper + water. The process of taking oxygen away from a substance is called reduction..." -Brownlee 1907
Brownlee, Raymond B., Fuller, Robert W., Hancock, William J., Sohon, Michael D., Whitsit, Jesee E. First Principles of Chemistry (Boston: Allyn and Bacon, 1907) 31
