Tungsten-filament Lamp

 Another success of chemistry. After tungsten replaced carbon in its filament, the lightbulb was considered “perfected.” As of 2013 they are being phased out worldwide in favor of compact fluorescent bulbs, which are four times as efficient.

Source: http://www.scientificamerican.com/article/inventions-what-are-the-10-greatest-of-our-time/?page=2