This is the replica of one of the earliest gas discharge lamp ever made: the electrical egg of sir Humphrey Davy. This device, devised in the early 19 century, is composed of a glass bulb provided with a pair of metal or carbon electrodes. The bulb could be filled with various gases and vapors, at different pressures, so the light emission of electrical discharges could be investigated in a variety of situations. (Palais de la decouverte, Paris, France)
