Camphor is a white, waxy substance with a strong, distinctive smell that comes from the wood of camphor trees, which grow naturally in parts of Asia. It can also be made chemically in laboratories. When you open an old trunk or closet and smell that sharp, almost medicinal scent, you're probably smelling camphor or mothballs made from it.

For centuries, people have used camphor to protect stored clothes from moths and other insects that eat fabric. It also appears in some chest rubs and ointments used for coughs and sore muscles. Camphor can be dangerous if misused, so it must be handled carefully.

Camphor has an unusual property: it sublimates, meaning it turns directly from a solid into a gas without becoming liquid first, like dry ice. This is why camphor slowly disappears when left in the open air, releasing that characteristic scent as it sublimates. In some cultures, people burn small amounts of camphor in religious ceremonies because of its purifying smell and the way it burns with a bright, smokeless flame.