The origins of “in the limelight,” which refers to being the focus of public attention, are linked to a type of stage lighting that was popular in the 19th century. The “lime” in limelight has nothing to do with the green citrus fruit but rather with a chemical compound, calcium oxide, also known as quicklime. In the early 1820s, English inventor Goldsworthy Gurney, improving on the work of earlier scientists, developed a blowpipe that burned hydrogen and oxygen to create an extremely hot flame. When Gurney heated calcium oxide in the flame it produced an intense white light, dubbed limelight. A Scottish military engineer, Thomas Drummond, learned about Gurney’s work and around the mid-1820s devised the first practical use for limelight, as a surveyor’s tool. When landmarks and reference points were lit with Drummond’s bright light they could be observed from great distances by surveyors, enabling for more accurate measurement-making.
In 1837, limelight was used for the first time to illuminate a stage, at London’s Covent Garden. During the second half of the 19th century, theaters regularly utilized this powerful form of light, which could be focused into a beam to spotlight specific actors or an area of the stage, as well as create special effects such as sunlight or moonlight. However, a downside to limelight was that each light needed someone to monitor it and make adjustments to the block of lime as it burned. Additionally, this type of lighting proved to be a fire hazard. In 1879, Thomas Edison demonstrated the first practical electric light bulb and by the end of the 19th century most theaters had switched from limelight to electricity, which was safer and more economical. Nevertheless, this development didn’t signal lights out for “in the limelight,” which remains a common expression.