A type of primary voltaic cell with
a copper positive electrode and a negative electrode
of a zinc amalgam.
Invented in 1836 by the British chemist John Daniell
The zinc amalgam electrode is
placed in an electrolyte of dilute sulphuric acid
or zinc sulphate solution in a porous pot, which stands
in a solution of copper sulphate in which the copper
electrode is immersed. While the reaction takes place,
ions move through the porous pot, but when it is not
in use, the cell should be dismantled to prevent the
diffusion of one electrolyte into the other.
e.m.f of the cell is 1.08 volts with sulphuric acid
and 1.1 volts with zinc sulphate.