All sperm whale's head "melons" contain a considerable amount of spermaceti oil. In a sperm whale, the amount can reach up to 500 gallons. In smaller whales, the oil amount is proportionate. Spermaceti oil was a valuable waxy substance historically used for making candles, ointments, lubricants, and whatnot. Whaling was very popular in the 18th and 19th Centuries for these oils. This commodity alone has created a huge industry once. Spermaceti lamp oil was so widespread that popular literary pieces like Moby Dick had covered a great deal about the industry.