Gas lighting is production of artificial light from combustion of a gaseous fuel, such as hydrogen, methane, carbon monoxide, propane, butane, acetylene, ethylene, or natural gas.The light is produced either directly by the flame, typically using special mixes of illuminating gas to increase brightness, or indirectly with other components such as the gas mantle or the limelight, with the gas primarily functioning as a heat source.Before electricity became sufficiently widespread and economical to allow for general public use, gas was the most popular means of outdoor and indoor lighting in cities and suburbs.