Mercury and Mars are ingredients in potions. These ingredients were kept with other potion ingredients in the Potions Classroom at Hogwarts School of Witchcraft and Wizardry.

Mercury probably refers to the poisonous liquid, while Mars may be a reference to Iron, since Mars represents the said Element in Alchemy .

Behind the scenes

  • Mercurialis is a genus of plants in the family Euphorbiaceae, the spurges, known commonly as the mercuries. These are slender herbs (forbs), rhizomatious perennials and woody perennials. There is 1 Asian species and 8 to 10 European species (depending on classification) of which annual mercury and dog's mercury are highly poisonous. Rue is a herb belonging to the genus Ruta and was also known as Mars' herb by the Romans, because it was used as a purifiying agent for cleaning iron (the metal of Mars). Another reason is that its essential oil can be a very irritating agent and can easily cause burns and blisters on the skin if applied, which makes it as fierce as the God himself. It has a very bitter taste.
  • In Harry Potter and the Chamber of Secrets (film), it was listed as an ingredient in a recipe for the Polyjuice Potion. Pottermore, however, presented a recipe that did not include it, being in-line only with the ingredients listed in the original Harry Potter and the Chamber of Secrets novel.


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