Cures like, similia similibus curantur, the Romans believed, like many ancient people before them, and they commonly bound hairs of a dog that had bitten someone to that person’s wound in order to make it heal better – even if the dog was rabid. The treatment was recommended for centuries by serious medical books, about the only change until medieval times being that burnt hair of the dog that bit you was prescribed. By then it was also believed that the best cure for a hangover was a drink of the same poison that stifflicated you the night before and the old proverb a hair of the dog that bit you applied to this practice. The first mention of the phrase in reference to hangovers is in John Heywood’s Proverbs (1546): “I pray thee leat me and my fellow have a heare of the dog that bote us last night – and bitten were we both to the braine aright.” Today virtually no one puts dog’s hair on dog bites, but a hair of the dog that bit you is still a universal “remedy” for a hangover. The practice makes some sense, too, for alcohol sedates those rebounding nerves that make hangovers so acutely painful.