The best light of all came from whale oil, and the best type of whale oil was spermaceti from the head of the sperm whale. Sperm whales are mysterious and elusive animals that are even now little understood. They produce and store great reserves of spermaceti—up to three tons of it—in a cavernous chamber in their skulls. Despite its name, spermaceti is not sperm and has no reproductive function, but when exposed to air it turns from a translucent watery liquid to a milky white cream—and it is obvious at once why sailors gave the sperm whale its name.
