The following recipe for a surgical narcotic known as dwale was discovered in a late medieval English manuscript found in the, Cambridge University Library and {translated into modern English by Linda E. Voigts and Robert P. Hudson. Dwale includes a variety of potent sleep-inducing herbs, as well as swine gall and vinegar to help extract the active ingredients from the herbs. It would in fact render a patient unconscious

To make a drink called dwale to make someone sleep while others carve [perform surgery] on him: Take three spoon- fills of the gall of a barrow/swine, [castrated boar] and for a woman; of a gilt [immature sow], three spoonfuls of hemlock juice, three spoonfuls of wild nept [briony], three spoonfuls of lettuce [sap], three spoonfuls of poppy three spoonfuls of henbane, and three of vinegar, and mix them...