he electric egg was used to demonstrate glowing electrical discharges in rarefied or thinned air. A vacuum pump was used to remove the air from the egg. When a charge from an electrostatic generator or Leyden jar was applied to the top electrode of the egg, the light created inside the egg could be seen. Then, more air could be pumped out, or some air or another gas let it, and a new glow could be observed. The electric egg can be considered to be one of the first means of producing an electric light.