"We may test other solutions by arranging the following circuit, including a source of current, the substance to be tested, and some instrument to detect the passage of the current." -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) 109
