Ishmael takes a time-out to discuss the whale’s skin. Where/what is it?
The whale’s blubber is obvious—a layer between eight and fifteen inches thick all over the whale’s exterior. But is that the whale’s skin? It’s so thick that it seems like something else, but it is the whale’s outermost layer.
Of course, there is a really thin transparent layer on the very outside of the blubber that you can scrape off and dry.
Ishmael uses pieces of it as bookmarks and thinks that sometimes they act like magnifying glasses. But he thinks of this, not as the whale’s skin, but as the skin of the skin.
So, if the blubber is the skin, Ishmael tells us, it gives about 100 barrels of oil, which is about 75% of the mass of the blubber—which gives you some idea how massive it is.
One strange aspect of a whale’s outside (Symbolism Alert!) is that there seem to be strange lines and markings all over the whale, not on, but rather, underneath that very thin transparent layer.
Ishmael regards them as hieroglyphics of some kind.
The blubber is called the "blanket piece" because it is the whale’s blanket. As warm-blooded mammals, whales have to keep their blood warm just as people do, and the blubber is the amazing insulation that they use to stay alive even in arctic waters.
Ishmael wishes that men would take the whale as an example and learn to be warm in the arctic and cool in the equator—to "live in this world without being of it" (68.7).