Entheogens aren't the first thing that comes to mind when contemplating Freemasonry. However, we know that many of the ancient Mystery traditions were possessed of their own psychedelic sacraments, e.g. kykeon in the Eleusinian Mysteries, soma in the Vedic Mysteries, etc. As Freemasonry purports to be a repository and continuation of the ancient Mysteries, it is actually quite fitting that we find a psychedelic tradition at the heart of certain 18th century Masonic rituals.
Look for my first post later today!