Scientists have found that the heart of King Richard I, who ruled England in the 12th-Century, was preserved using mercury, mint and frankincense, among other sweet-smelling plants.
The king's heart was removed and mummified separately from the rest of his body when he died in
1199. It rested in a reliquary at Notre Dame in Rouen for centuries before its rediscovery in 1838.
Scientists have found the chemical composition of the substances used to preserve the heart, LiveScience reported.