An easy cell to construct is the citrus cell. Stick a paper clip and a piece of copper wir...

An easy cell to construct is the citrus cell. Stick a paper clip and a piece of copper wire into a lemon.

Hold the ends of the wire close together, but not touching, and place the ends on your tongue. The slight tingle you feel and the metallic taste you experience result from a slight current of electricity pushed by the citrus cell through the wires when your moist tongue closes the circuit.