ambergris

harmaa ambra, ambra A solid, waxy, flammable substance of a dull grey or blackish color, produced in the intestines of the sperm whale. It is used in perfumes.
1851 — w:Herman_Melville Herman Melville, s:Moby-Dick Moby Dick

And as for the other whale, why, I’ll agree to get more oil by chopping up and trying out these three masts of ours, than he’ll get from that bundle of bones; though, now that I think of it, it may contain something worth a good deal more than oil; yes, ambergris.