BATTERY, ELECTRIC PRIMARY

an arrangement of cells, elements, couples which produces a current electricity by chemical action. original voltaic cell consisted of a and a copper plate joined by a wire immersed in a weak acid solution. hydrogen liberated made a coating the copper (negative) plate, stimulated reverse action and thus weakened current (polarization). 'This was ated in the Daniell’s cell by placing copper in a solution of copper sulphate a porous pot, the hydrogen then ing the copper which was deposited the copper plate. In the Grove platinum foil is immersed in trated nitric acid, instead of copper copper sulphate. The Bunsen cell modification of the Grove cell, the pensive platinum plate being by a rod of carbon. In the Leclanché cell zinc rests in sal-ammoniac and a plate of carbon (replacing is placed in a porous pot packed manganese dioxide and bits of This is the cell generally used for bells, etc.