Sources of fuel for oil lamps include a wide variety of plants such as nuts (walnuts, almonds, and kukui) and seeds (sesame, olive, castor, or flax). Also widely used were animal fats (butter, ghee, fish oil, shark liver, whale blubber, or seal). Camphine, a blend of turpentine and ethanol, was the first "burning fluid" fuel for lamps after whale oil supplies were depleted. It was replaced by kerosene after the US Congress enacted excise taxes on alcohol to pay for the Civil War.