Leviathan

The broad palms of his tail are flirted high into the air; then smiting the surface, the thunderous concussion resounds for miles. You would almost think a great gun had been discharged; and if you noticed the light wreath of vapor from the spiracle at his other extremity, you would think that that was the smoke from the touch-hole.

Fifth: As in the ordinary floating posture of the leviathan the flukes lie considerably below the level of his back, they are then completely out of sight beneath the surface; but when he is about to plunge into the deeps, his entire flukes with at least thirty feet of his body are tossed erect in the air, and so remain vibrating a moment, till they downwards shoot out of view.

It designates the dark, glutinous substance which is scraped off the back of the Greenland or right whale, and much of which covers the decks of those inferior souls who hunt that ignoble Leviathan.