Meidinger’s Battery

A variety of Daniell cell of the gravity type. The plates are cylindrical. The zinc plate lies against the upper walls of the vessel. The copper plate of smaller diameter rests on the bottom. A large tube, with an aperture in its bottom, is supported in the centre and is charged with copper sulphate crystals. The cup is filled with a dilute solution of Epsom salts (magnesium sulphate) or with dilute sulphuric acid.