In Shakespeare’s Macbeth, the three witches brew a potion with ingredients chosen to symbolise incredible evil. Amongst human organs and animal parts, the witches use the root of the deadly hemlock (Conium maculatum), a highly poisonous plant known to have a chemical structure and pharmacological properties similar to nicotine. Even in low doses, the plant can cause respiratory failure and death. The root of the plant, used by the witches in their deadly concoction is known to have the highest toxicity concentration of all of the plant.