described the procedure. In the first half of the twentieth century, teething powders in the English-speaking world often contained calomel, a form of mercury. It was removed from most powders in 1954 when it was shown to cause "pink disease" (acrodynia), a form of mercury poisoning. Teething toys have a long history. In England in the 17th–19th centuries, a coral meant a teething toy made of coral, ivory, or bone, often mounted in silver as the handle of a rattle. A museum curator has suggested that these substances were used as sympathetic magic, and that the animal bone could symbolize animal strength to help the child cope with pain. See also Tooth eruption Deciduous teeth Permanent teeth Dentition References External links NHS Choices Birth to Five Planner: Teething NHS Choices Health A–Z: Teething Infancy Pediatrics Teeth