# Moby-Dick (1851) US edition/Chapter 77

Chapter LXXVII.
the great heidelburgh tun.
Now comes the Baling of the Case. But to comprehend it aright, you must know something of the curious internal structure of the thing operated upon.
Regarding the Sperm Whale’s head as a solid oblong, you may, on an inclined plane, sideways divide it into two quoins, whereof the lower is the bony structure, forming the cranium and jaws, and the upper an unctuous mass wholly free from bones; its broad forward end forming the expanded vertical apparent forehead of the whale. At the middle of the forehead horizontally subdivide this upper quoin, and then you have two ​almost equal parts, which before were naturally divided by an internal wall of a thick tendinous substance.
The lower subdivided part, called the junk, is one immense honeycomb of oil, formed by the crossing and re-crossing, into ten thousand infiltrated cells, of tough elastic white fibres throughout its whole extent. The upper part, known as the Case, may be regarded as the great Heidelburgh Tun of the Sperm Whale. And as that famous great tierce is mystically carved in front, so the whale’s vast plaited forehead forms innumerable strange devices for the emblematical adornment of his wondrous tun. Moreover, as that of Heidelburgh was always replenished with the most excellent of the wines of the Rhenish valleys, so the tun of the whale contains by far the most precious of all his oily vintages; namely, the highly-prized spermaceti, in its absolutely pure, limpid, and odoriferous state. Nor is this precious substance found unalloyed in any other part of the creature. Though in life it remains perfectly fluid, yet, upon exposure to the air, after death, it soon begins to concrete; sending forth beautiful crystalline shoots, as when the first thin delicate ice is just forming in water. A large whale’s case generally yields about five hundred gallons of sperm, though from unavoidable circumstances, considerable of it is spilled, leaks, and dribbles away, or is otherwise irrevocably lost in the ticklish business of securing what you can.
I know not with what fine and costly material the Heidelburgh Tun was coated within, but in superlative richness that coating could not possibly have compared with the silken pearl-colored membrane, like the lining of a fine pelisse, forming the inner surface of the Sperm Whale’s case.
It will have been seen that the Heidelburgh Tun of the Sperm Whale embraces the entire length of the entire top of the head; and since—as has been elsewhere set forth—the head embraces one third of the whole length of the creature, then setting that length down at eighty feet for a good sized whale, you have more ​than twenty-six feet for the depth of the tun, when it is length-wise hoisted up and down against a ship’s side.
As in decapitating the whale, the operator’s instrument is brought close to the spot where an entrance is subsequently forced into the spermaceti magazine; he has, therefore, to be uncommonly heedful, lest a careless, untimely stroke should invade the sanctuary and wastingly let out its invaluable contents. It is this decapitated end of the head, also, which is at last elevated out of the water, and retained in that position by the enormous cutting tackles, whose hempen combinations, on one side, make quite a wilderness of ropes in that quarter.
Thus much being said, attend now, I pray you, to that marvellous and—in this particular instance—almost fata. operation whereby the Sperm Whale’s great Heidelburgh Tun is tapped.