By setting up a pickle as a resistor and applying a voltage, the sodium in the pickle glows a characteristic yellow.
Make sure that the pickle is unplugged before touching it.
Pickle (the higher the sodium content, the better)
two corks each with a three inch nail (the nail should protrude out each end of the cork)
cork impaled with copper electrodes
Alligator leads for attaching to an electrical source
Electrical source, supplying 120
two ringstands and two clamps
Attach a clamp to each ringstand. Secure a cork into each clamp such that the points of the nails point horizontally at each other. Attach an alligator lead to the flat end of each nail. Place the pickle on the point of the nails. Connect the leads to the electrical source and dim the lights. The pickle will glow orange (possibly due to electrical excitation of sodium ions present).
Added suggestion: Add a Sodium salt flame test or a Sodium spectrum lamp to show a more pure source for the same glow.
Tips of the copper skewers need to be close, but not touching. Wood sticks parallel to the electrodes works well to estimate location of copper ends in the pickle.
Web references suggest curing pickles in different salts result in different emission spectra.