Hmm.. it's a long read, maybe a bit of a summary for those who are topically interested
The first half is basically is a collection of trip reports written by a guy who was into the 19th century practice of eating "hasheesh"... He describes many, many aspects of the psychedelic experience, feelings of oneness, separation of mind/body, ecstasis, catharsis, synesthesia, space time distortions, hallucinations (aural and visual), overwhelming creativity, etc etc. Goes into a lot of detail too, into the mental aspects of his trips, he really wants the readers to understand his experiences..
Anyway the second half.. His trips become more and more frequent and at some point they start to lose the magic.. he becomes psychologically addicted, has bad trips, gets freaked out. The second half of the book is about his attempt to quit his addiction, and then his own personal ideas about the nature of the senses, things he learned from his life and his trips. What's really cool about this book though is that a "theme" of it, he is really interested in the senses and how they work and that really is why he is sharing these experiences. So it's not all negative in the end, it really becomes more about his own inner demons and drug addiction in general. His perspective into how society should treat drug addicts is somewhat interesting as well.. He sure hates opium though
