Christmas crackers are an important part of Christmas celebrations in many English-speaking countries, especially in the United Kingdom, Ireland, Australia, New Zealand, Canada, and South Africa. A cracker consists of a cardboard tube wrapped in coloured paper with a gift, a crown-like paper hat, and a motto or joke on a small piece of paper inside the central chamber. One person pulling one end of the cracker, another person the other end. When the cracker splits a snapping sound, similar to the sound produced by a cap gun, can be heard. This is due to the presence of a card strip impregnated with a special chemical inside the cracker. Christmas crackers are commonly pulled at the Christmas dinner table. The joke or riddle is told and the hat worn during the meal. The tradition of pulling crackers at Christmas dates back to at least the mid 19th century.