What is the significance of alchemy in Freemasonry?

Mackey views the philosopher's stone of the Alchemists and the spiritual temple of Freemasons as identical symbols, both representing the moral duty of a man to do good and walk humbly in his vocation 1. In Craft tradition, the alchemical art—also termed the Hermetic Science—is traced to Hermes Trismegistus 1. Operative Masons incorporated Hermes into the old Constitutions and the Legend of the Craft, viewing him as a central figure who preserved ancient knowledge and taught communication through signs 1.

Alchemical concepts entered Freemasonry largely through Hermetic philosophy and Rosicrucian thought, exercising their greatest influence on high-degree systems rather than the basic Craft degrees 12. Hermetic philosophy utilizes a dual symbolism and attempts to explain natural phenomena through salt, sulphur, and mercury 1. These principles informed specialized Masonic bodies, including the Hermetic Rite at Avignon and the Philosophic Scottish Rite founded in 1775, which explicitly integrated Hermetic teachings into its high degrees 1.

In the Scottish Rite, alchemical and Rosicrucian symbolism is prominent in degrees such as the Eighteenth Degree 12. Historical linkages between Masons and Rosicrucians appear as early as 1638 in Henry Adamson's poetry, though scholars like Waite view Rosicrucianism not as the origin of Freemasonry, but as a significant influence during its period of extension and high-degree development 2.