Thomas W Hodgkinson at The Guardian:

Before writing this review, I got hold of some tiny canisters of nitrous oxide, filled a balloon or two and, watched by my bemused wife, breathed in the gas. It gave me no more of a buzz than smoking a cigarette. I must have been doing it wrong because, according to Mike Jay’s compelling history of narcotic self-exploration, it was when the chemist Humphry Davy began inhaling this newly discovered gas in Bristol in 1799, sometimes in the company of the poet Samuel Taylor Coleridge, that he started a revolution. While high, Davy declared that “Nothing exists but thoughts!”

This insight wasn’t new, of course. Bishop Berkeley had made it the cornerstone of his philosophy. Yet for Davy, it felt transformative. Another laughing gas lover, the psychologist William James, later observed that there are two types of people: the once-born and the twice-born. The once-born accept the world as it is and get on with it. The twice-born have a life-changing insight or vision. Some become questing, drug-ingesting “psychonauts” as a result – and it is they who form the focus of this fascinating book.

more here.