Peace, comfort, reverence, gaiety—all of these emotions and more are symbolized by the flame of a candle. But for thousands of years, candles also served as humankind's main source of lighting. Although experts differ on just who invented the candle and when, it is believed that primitive forms of candles were used by ancient civilizations in Egypt, Crete, and Italy. The candle may have begun to evolve when hunters, cooking meat over an open fire, noticed that the burning fat created a bright light. Early candles were made of this animal fat, called tallow, and of beeswax, which comes from honeycombs.Initially, reeds were utilized as a means of keeping the candle burning; eventually,the burning properties of candles were improved with the invention of fiber wicks. The modern braided wick, which burns itself up instead of having to be trimmed, was not introduced until 1824. By...