The term “limelight” is used to describe an oxycalcium light. It is also used refer to someone who is in the public eye, as a result of the widespread use of oxycalcium lights in theaters when they were first introduced. Actors and public officials are often said to be in the limelight, especially if they are facing heavy public criticism. Theater spotlights are called “limes,” a nod to the important role of oxycalcium lights in theater history. The intended usage of the word is usually clear in the context.
In the 1820s, a man named Goldsworthy Gurney discovered a new form of lighting by directing two jets of oxygen and hydrogen at a ball, disc, or rod of calcium oxide, also known as lime. The jets of gas were ignited, and heated the calcium oxide to the point where it would begin to emit extremely bright white light. The invention was picked up by Thomas Drummond, who is sometimes mistakenly credited with the invention of the limelight. The concept of heating a material until it emits light, otherwise known as incandescence, is the same principle behind the operation of most modern lightbulbs.
Drummond could see that there were a number of potential applications for limelight illumination systems. Because of the high visibility, the light could be used on lighthouses and for other outdoor work such as surveying. But it could also be used indoors, and was readily adopted by theatres, since it lit up the stage extremely well. Actors and actresses would jockey for positions on stage so that they would be in the limelight, clearly illuminated and visible to the audience.
The idea of being “in the limelight” entered popular slang, and quickly came to describe anyone who was under the public eye. Celebrities, politicians, public officials, and others are often subjected to almost uncomfortably close scrutiny. They are said to be in the limelight because the scrutiny resembles a glaring white light, revealing all flaws of character and conduct. Not everyone is capable of withstanding the pressure of close examination.
Although theaters no longer use oxycalcium lights, the concept of the limelight and limes is retained as part of the rich cultural tradition of theatrical performance. Most actors and actresses on stage and screen understand the term, and also appreciate being in the bright light of a spotlight, or lime. The limelight is most closely associated with theatrical performances because of the implied romance of acting in the 19th century, when limelights were used extensively in theatres.