Sacks’s weekend drug experimentation escalated: a cocktail of amphetamine, LSD, and cannabis let him see true indigo, a color unknown in nature, while morning-glory seeds gave him the conviction that a visitor, in actuality a psychoanalyst colleague of Sacks’s physician parents, was in fact only a replica of the woman he knew. In London, after extracting morphine from the drug cabinet in his parents’ home office and injecting it, he enjoyed a spectacular hallucination of the Battle of Agincourt on the sleeve of his dressing gown, remaining immersed in the vision for more than twelve hours; the span of time lost sufficiently alarmed Sacks that he gave up opiates altogether. In New York, he suffered acute delirium tremens after the sudden cessation of a serious chloral hydrate habit, experiencing intense hallucinations and fending off panic only by writing a clear, almost clinical account of what he saw. It was during this period that Sacks’s vocation as a writer would emerge, and the theme of writing as refuge and remedy will return in Hallucinations as a refrain.

more from Jenny Davidson at Bookforum here.