The word “lime” refers not to just the small citrus fruit, but also to a chemical compound known as calcium oxide, which is often called “quicklime.” In the early 19th century, an inventor named Goldsworthy Gurney invented a lighting technique in which he heated calcium oxide in a flame generated from burning hydrogen and oxygen. The product was an intense white light that was named “limelight”. Limelight was first used in long-distance surveying, until in 1837, when it was first used to light up a theater stage in Covent Garden in London. For the remainder of the 19th century, theaters all over the world started using limelight in the form of a concentrated spotlight beam to focus on specific actors or zones on stage, and to create sunlight, moonlight and other special effects. When the limelight was shone on an actor, it was a way of directing the audience’s attention toward that person. That’s how the phrase “to be in the limelight” came to mean “to be at the center of people’s attention.”