Peppermint was the most popular of the mint family to be used in culinary and medicinal concoctions. It displays stimulating and carminative properties, and is also used for general stomachache and nausea. It was often combined with other bitter or foul-tasting drugs to make them more palatable.
References:
Grieve, M. (Maud). A Modern Herbal; the Medicinal, Culinary, Cosmetic and Economic Properties, Cultivation and Folk-Lore of Herbs, Grasses, Fungi, Shrubs, & Trees with All Their Modern Scientific Uses. New York :Harcourt, Brace & company, 1931.