Baghdad Battery
The Baghdad Battery, sometimes referred to as the Parthian Battery, is the common name for a number of artifacts created in Mesopotamia, possibly during the Parthian or Sassanid period (the early centuries AD). These jars were probably discovered in 1936 in the village of Khuyut Rabbou'a, near Baghdad, Iraq. These artifacts came to wider attention in 1938 when Wilhelm König, the German director of the National Museum of Iraq, found the objects in the museum's collections. In 1940, König published a paper speculating that they may have been galvanic cells, perhaps used for electroplating gold onto silver objects.[2] This interpretation continues to be considered as at least a hypothetical possibility. If correct, the artifacts would predate Alessandro Volta's 1800 invention of the electrochemical cell by more than a millennium.
http://en.wikipedia.org/wiki/Baghdad_Battery