Ralph Metzner and The Philosopher's Stone

Ralph Metzner (b. 1936)  - psychotherapist, psychonaut, writer, researcher and original member of the Harvard psychedelic "trimurti" together with Timothy Leary and Richard Alpert (Ram Dass) - is a prolific author of books dedicated to the "perennial philosophy",  modified states of consciousness, shamanism, ethnobotany, meditation etc.
Metzner's new book "Searching for the Philosopher's Stone" (Inner Traditions, 2018) is a personal account of meetings and friendships - from the 1960s onward with shamans, healers, mystics and psychedelic luminaries like Albert Hofmann, "Sasha" Shulgin and the McKenna brothers.
I strongly recommend this book to all the people interested in similar fascinating topics and I also suggest to give a look to Metzner's rich bibliography.
You can buy the book directly from the publisher here or from Amazon and other sources.