We have lost a great scientist --Alexander Shulgin. I call him "great" not because of any groundbreaking insight he had, but because of his determination to explore and report on a part of the world that others would willfully ignore. In the mold of scientific legends, he pressed on with his investigations despite ostracism and harassment.
He has left us with many writings, but as far as I know, the capstones are PIHKAL: A Chemical Love Story, and it's follow-up TIHKAL: The Continuation.