mucholderthen:

CHEMISTRY IN THE NINETEENTH CENTURY
Clark’s Standard Cell
A form of wet-chemical cell [more informally, “battery”]producing a highly stable voltage once used as a standard for electromotive force

Clark cells use a zinc, or zinc amalgam, anode and a mercury cathode in a saturated aqueous solution of zinc sulfate, with a paste of mercurous sulfate as depolarizer.
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Upper graphic:  X  - 1891:  Benson John Lossing, ed. The New Popular Educator (London, England: Cassell & Company Limited)

Lower graphic: X  -   1897:  Physikalisches Praktikum mit besonderer Berücksichtigung der physikalischen-chemischen Methoden - von Eilhard Wiedemann und Hermann Ebert;  Braunschweig, Friedrich Vieweg und Sohn; 1897
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BATTERY:  a device that converts chemical energy directly to electrical energy.

MOST BASIC COMPONENT OF A BATTERY:  two half-cells that are connected by a conductive electrolyte.

• One half-cell includes electrolyte and the electrode to which anions (negatively charged ions) migrate, i.e., the anode or negative electrode
• The other half-cell includes electrolyte and the electrode to which cations (positively charged ions) migrate, i.e., the cathode or positive electrode.  [  X  ]

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(via scientificillustration)