Incandescent first lit up the English language toward the end of the 18th century, at a time when scientific experiments involving heat and light were being conducted on an increasingly frequent basis. An object that glowed at a high temperature (such as a piece of coal) was incandescent. By the mid-1800s, the incandescent lamp—aka the lightbulb—had been invented; it contains a filament which gives off light when heated by an electric current. Incandescent is the modern offspring of a much older parent, the Latin verb candēre, meaning "to glow." Centuries earlier, the word for another source of light, candle, was also derived from candēre.