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Hellebore and Aconite were the favourite poisons of the Marquise de Brinvilliers and other specialists of the Middle Ages. The Christmas Roses or Hellebores were known to be poisonous fourteen hundred years before the Christian era, and are still used in medicine. Aconite, which has a tuberous root-stock, is dangerous, for it is occasionally eaten in mistake for the horse-radish, to which it has a faint resemblance. All kinds of aconite are poisonous. That of one of the Indian species is used to tip the arrows employed in shooting tigers.