"Now this Ambergris is a very curious substance, and so important as an article of commerce, that in 1791 a certain Nantucket-born Captain Coffin was examined at the bar of the English House of Commons on that subject."
We can see that if Melville can find a way of giving some ink to Nantucket and Natucketers, he will do so willingly.
Now ambergris is French for grey amber, but it has nothing to do with amber itself, which is a hard, brittle, transparent substance formed from the congealed sap of certain trees. It is used to form mouth-pieces for tobacco pipes, and specimens of it are prized for the insects which have been trapped within it -- some for millions of years.
Ambergris is different -- much different. "Ambergris is soft, waxy, and so highly fragrant and spicy, that it is largely used in perfumery, in pastiles [a medicated pill or a tablet burned to deodorize the air], precious candles, hair powders, and pomatum [a perfumed ointment for hair or scalp]. The Turks use it in cooking, and also carry it to Mecca, for the same purpose that frankincense is carried to St. Peter's in Rome. Some wine merchants drop a few grains into claret [a French red table wine] to flavor it. Who would think, then, that such fine ladies and gentlemen should regale themselves with an essence found in the inglorious bowels of a sick whale! Yet so it is. By some, ambergris is supposed to be the cause, and by others the effect, of the dyspepsia in the whale."
Melville then makes a sort of sick joke about trying to cure the whale's dyspepsia (upset stomach) with a laxative. The reader is commended to the actual text of M-D (Moby-Dick) for the joke verbatim.
On the subject of smells, Melville takes the opportunity to refute the conviction that all whales always smell bad. This incorrect notion stems, says he, from the practice of English Greenland whalers of storing whale blubber in barrels rather than turning it into oil (trying it out) at sea the way Sperm whalers do. Another source of this bad impression concerning whales, whalers, and whale oil is the story about the stinking Dutch village on the coast of Greenland where the Dutch whale fleet unloaded blubber to be boiled into oil to take back to Holland.
"But all this is quite different with a South sea Sperm Whaler which in a voyage of four years perhaps, after completely filling her hold with oil, does not, perhaps, consume fifty days in the business of boiling out; and in the state that it is casked, the oil is nearly scentless. The truth is, that living or dead, if but decently treated, whales as a species are by no means creatures of ill odor; nor can whalemen be recognized . . . by the nose."