During World War II, the United States Navy added a small amount of croton oil to the neutral grain spirits which powered torpedoes. The oil was intended to prevent sailors from drinking the alcohol fuel. Sailors devised crude stills to separate the alcohol from the croton oil, as alcohol evaporates at a lower temperature than croton oil. Norwegian partisans, ordered by the Quisling government to turn over a catch of sardines to the Nazi German government for shipment to Saint-Nazaire (a U-boat base of operations) arranged with the British for a large shipment of croton oil to poison the sardines, whose fishy taste was expected to conceal the tampering.