transmutation

He decorated Arca Arcanorum with an emblem copied from a medieval alchemical scroll, illustrating the allegorical process of alchemical transmutation necessary for the Philosophers’ Stone.

The ship set sail in 1831, but it wasn’t until 1835, on a visit to the Galapagos Islands toward the end of the voyage, that Darwin began to formulate his theory of natural selection, which at the time was referred to as “transmutation of species.”