In chapter 91, Stubbs comes across a French ship, the Bouton-de-Rose, that stinks to the high heavens from rotting whale flesh. The first mate of the French ship speaks English and tells Stubb that the captain of this ship is on his first voyage, was a former cologne manufacturer, and is a fool who knows nothing of whales. He tells Stubb, too, that the French crew is disgusted with having to cut into the whales, as the smell is appalling.
Stubb and the French first mate devise a plot in which the first mate tells the captain that Stubb has said it is dangerous for them men to keep the rotting dead whales on board because the whales are in a state where they can easily transmit a life-threatening fever to humans. The captain thanks Stubb for this information, and Stubb says he will help them get rid of the whales.
Stubb is acting as a trickster, for he knows the stinking carcasses have great value. He digs into one with his shovel until he gets to the valuable ambergris, which is described as:
like ripe Windsor soap, or rich mottled old cheese; very unctuous and savory withal. You might easily dent it with your thumb; it is of a hue between yellow and ash colour. And this, good friends, is ambergris, worth a gold guinea an ounce to any druggist.
Stubb's quick trickster thinking and knowledge of whales allows the Pequod's crew to gain a precious commodity that the less experienced French crew doesn't know how to value.