Who indeed can fathom the depths of London? Any such attempt could well be dangerous, and if I sound like the Surgeon General or a government health warning — or perhaps that sign above the doors on the London Underground — at least I have the comfort of knowing I am not alone in my eccentric wariness. Thomas de Quincey understood something about the injurious aspects of London, which many subsequent writers have not, when he wrote, "in these three functions of sleep, diet, exercise, is contained the whole economy of health: and all three are woefully deranged by a London life". There is an echo of De Quincey's sentiment in an internalized, psychologizing comment by Iain Sinclair. In London Orbital, Sinclair writes that "the person who undertakes research into the city's history, minutiae and odd particulars, will become unbalanced" (LO 171). Finally, as if in affirmation of both De Quincey and Sinclair, the body and psyche of the London subject are both comically and seriously rewritten by the city in Geoff Nicholson's Bleeding London, when Judy Tanaka tells her therapist: ""I display signs of both renewal and decay. Strange sensations commute across my skin. There is vice and crime and migration. My veins throb as though with the passage of underground trains. My digestive tract is sometimes clogged.