Electric light bulb lamp. Animation showing how the flow of electricity (yellow and white) down electrical wires, supplies the power for an electric light bulb in a lamp. An incandescent light bulb consists of a sealed glass bulb encasing a metal filament under an inert gas. The electric current flows through a filament made from tungsten. (melting point of 3410 degrees Celsius). The filament heats up and glows as current passes through it, lighting up the surroundings through the glass. Although protected from the oxygen in the atmosphere, the tungsten metal still evaporates, and the filament eventually breaks.