I'll probably finish the book today, but I will without doubt refer back to this book in the future. While the lack of referencing is really grating on me (hence my mentioning it again), there are enough cues in the chapter to use as starting point for further research, or in my case, Google-fu.
I stopped reading last night just before I got to the chapters on Nicotine and Caffeine, which I enjoyed this morning (over coffee, of course).
However, I still get the feeling that the author is somewhat preoccupied with some of the molecules more than others:
"Chocolate contains another interesting compound, anandamide, which has been shown to bind to the same receptor in the brain as the phenolic compound tetrahydrocannabinol (THC), the active ingredient in marijuana, even though the structure of anandamine is quite different from the structure of THC. If anandamide is responsible for the feel-good appeal that many people claim for chocolate, then we could ask a provocative question: What is it that we want to outlaw, the THC molecule or its mood-altering effect? If it is the mood-altering effect, should we be considering making chocolate illegal?"
Still, the chapter on Caffeine (including tea and chocolate) has been my favourite so far. :D