The following Figure illustrates the principle of a Daniell cell
in which copper and zinc metals are immersed in solutions of
their respective sulfates. Schematic of a Daniell cell. The
Daniell cell was the first truly practical and reliable electric
battery that supported many nineteenth century electrical
innovations such as the telegraph. In the process of the
reaction, electrons can be transferred from the corroding zinc
to the copper through an electrically conducting path as a
useful electric current. Zinc more readily loses electrons than
copper, so placing zinc and copper metal in solutions of their
salts can cause electrons to flow through an external wire which
leads from the zinc to the copper. (reference) The difference in
the susceptibility of two metals to corrode can often cause a
situation that is called galvanic corrosion named after Luigi
Galvani, the discoverer of the effect. The purpose of the
separator shown in the previous Figure is to keep each metal in
contact with its own soluble sulf