The author, a wine critic, has written a delightful appreciation of intoxication and the means by which humans have sought it from prehistory to the present. Seeing the pursuit of ecstasy, given its ubiquity, as a species given, Walton delivers as well a critique of the various wars on drugs from the Islamic prohibition of terrestrial alcohol (wine is fine in the afterworld) thru Nixon and Reagan and the contemporary government of the U.K.
While refreshingly positive about the use of drugs from caffeine and nicotine to opium and cocaine, Walton does acknowledge that some intoxicants are inherently dangerous. He sees little to recommend the sniffing of glues or gasolene. He does note, however, that the prohibition of relatively innocuous drugs, such as pot, can lead kids towards the really dangerous stuff, like the inhalants, which are common, legal and readily available.
The best guide I know to the psychoactives conducive to intoxication/ecstasy is the book Buzzed, itself a sort of encyclopaedia. This sprightly text, sharing a similar practical perspective, might be taken as a gloss on that reference book.