Dr. Franz Hartmann was a notable Freemason and prolific writer of his day, as well as a member of several esoteric organizations, such as the Theosophical Society and a nonmasonic Templar Order. Here, he discusses the concept of the philosopher's stone, as studied by the Rosicrucians, and how it relates to alchemy. He talks about the incorruptible body, spiritual development, and the alchemical concept of base metal.

Originally published in 1910.