Originally posted by rifter:
You'll need another copper plate to make it a capacitor. The electrons have to flow from one plate to another.
Plate
Rock Salt/water
Plate
However, seeing as the rock salt will make the water conduct like crazy, this won't be a very good capacitor. Maybe if you use distilled/deionized water it will work. Or even better, oil.
(I should have stated, "pieces of copper" - sorry for the confusion there.)
I agree that it's not a very good capacitor for modern uses. Since natural DC is probably what they were working with, it seems that they were deliberately trying to attract the maximum environmental EMF by making this thing highly conductive...
