Gas Discharge tube

J. Plucker built one of the first gas discharge tubes.Gas discharge tubes allow an electric current to passed through a gas, the gas emits light. This emission is exploited in many electric lamps. Fluorescent lamps, “neon” signs, and mercury-vapor and sodium-vapor lamps are common examples of this kind of electric lighting, called gas-discharge lamps. The colors of gas-discharge lamps vary widely depending on the identity of the gas and the construction of the lamp. The gas discharge tube was created in 1859.