Gas-discharge lamp they create light from electricity considerably more efficiently than incandescent light bulbs. The father of the low-pressure gas discharge tube was German glassblower Heinrich Geissler, who beginning in 1857 constructed colorful artistic cold cathode tubes with different gases in them which glowed with many different colors, called Geissler tubes. It was found that inert gases like the noble gases neon, argon, krypton or xenon, as well as carbon dioxide worked well in tubes. This technology was commercialized by French engineer Georges Claude in 1910 and became neon lighting, used in neon signs. The introduction of the metal vapor lamp, including
Phase-out of incandescent light bulbs mercury contamination from CFLs have been raised, but CFLs can be shown to result in less mercury in the environment compared to traditional incandescent bulbs due to the significant reductions in power plant emissions. Thus, use of energy-efficient bulbs can actually reduce the amount of mercury released into the environment. Compact fluorescent lamps start poorly when very cold, and most types cannot be dimmed. A few specialist applications are unsuitable for CFLs. Light emitting diode (LED) lamps are used for both general and special-purpose lighting. Compared to fluorescent bulbs, their advantages are that they contain no mercury, they turn on