Many alchemical theories were closely related to numerology.

These were previously unavailable to Europeans who for the first time had a full picture of the alchemical theory that Bacon had declared absent.

These involved the familiar alchemical theory of metallic generation through interactions of sulfur and mercury.

In his early work, he demonstrated an avoidance of alchemical theory and an acceptance of Aristotelian theory.

Introduced to alchemical theory, he would later stylize himself as the "Philosopher by Fire."

His studies soon focused on chemical philosophy and alchemical theory.

The alchemical theories associated with Hermes Trismegistus, is the syncretism of the Greek god Hermes and the Egyptian Thoth.

A follower of Paracelsus, he is now remembered for important if transitional alchemical theories.

With the rise of Christianity and the decline of the Roman Empire, the atomic theory was abandoned for nearly two millennia in favor of the various four element theories and later alchemical theories.

(although they are based on "Islamic" alchemical theories)