Ambergris (Ambra grisea, Ambre gris, ambergrease, or grey amber) is a soli, waxy, flammable substance of a dull gray or blackish color produced in the digestive system of sperm whales. Ambergris has a peculiar sweet, earthy odor (similar to isopropyl alcohol); though it has now been largely displaced by synthetics, the principal historical use of ambergris was as a fixative in perfumery. The writer Herman Melville makes mention of ambergris in Moby-Dick. He discusses at length how ambergris was commonly found in dead whales floating in the South Pacific.