This week’s books podcast promises to be a trip. I’m joined by Mike Jay to talk about the history of mescaline — a psychedelic drug whose influence goes from the earliest South American civilisations through the 19th-century Indian Wars up to W B Yeats, Aleister Crowley and (of course) Aldous Huxley and Hunter S Thompson. Does tripping balls tell us anything profound about human consciousness? How come Mexico got all the good drugs? And why did Aldous Huxley lie about his trousers?