In criminal law, prisoners are stripped naked and put into a pot of boiling liquid, or put into cold liquid first and then heated to boiling. The liquid can be oil, acid, asphalt, water or molten lead. During the reign of Henry III, it was specially prepared for poisoned prisoners.
"In the preface of the Law of Henry III 153 1 (regarding poisoning as treason), the case of chef Richard Ruth was cited. He poisoned food for Bishop Rochester's family and the poor in Lamberthz, resulting in the death of a man and a woman. He was convicted of treason and sentenced to cooking, and he could not be exonerated. He was publicly tortured in Smithfield. In the same year, a maid was punished for poisoning her mistress in King Lynn. " (selected from Encyclopedia Britannica, 19 1 1 year)
In London's Chronicle of the Grey Friar (published by Camden Institution), an execution in Smithfield was recorded. A man was chained and thrown into boiling water several times until he died. In modern times, Idi Amin (no one can run faster, Ugandan dictator in 1970s) is accused of punishing his enemies in this way.