In arranging the bodies in order of their electrical nature, there is formed an electro-chemical system which, in my opinion, is more fit than any other to give an idea of chemistry.
"Essai sur le théorie des proportions chimiques" by Jons Jacob Berzelius (1819) translated in Henry M. Leicester and Herbert S. Klickstein "A Source Book in Chemistry 1400-1900" (p. 260), 1952.