A voltaic pile or battery. It is made of discs of paper, silvered or
tinned on one side and sprinkled on the other with binoxide of
manganese. Sometimes as many as 2,000 of such couples are piled up in a
glass tube and pressed together with two rods which form the terminals.
They maintain a high potential difference, but having very high
resistance and slight polarization capacity, give exceedingly small
quantities.