Peppermint (Mentha piperita), a British species of mint, cultivated for its aromatic essential oil at Mitcham (Surrey),Wisbeach (Cambridgeshire), Market Deeping (Lincoln), and Hitchin (Hertfordshire), but far more extensively in New York, Michigan, and Ohio. The whole plant, especially just before flowering, is rich in the oil, and when dried it yields three or four times more than when green. The English product is nearly 20 lbs. of oil per acre. It is used for flavouring sweetmeats and cordials, to conceal the taste of medicines, and as a carminative and stimulant, especially in flatulence. It is also one of the sources of menthol or Chinese oil of peppermint, C10Hl3 + H.,0, which is used externally in neuralgia.