concept

Spermaceti

A clear liquid wax held in a large chamber in the head of a sperm whale. Its biological role is still argued over — possibly acoustic focusing for echolocation, possibly buoyancy control. Its economic role was never in doubt: through the nineteenth century it was the finest lubricant and the best smokeless candle stock available, and it was obtained by severing the animal's head and bailing it out. An entire industry ranged across every ocean for that one chamber. This is the closest Earth precedent for hunting a large, long-lived animal solely for a fluid inside its skull — down to the detail that the rest of the animal was worth far less than what its head contained.