Why Are Vampires Uniquely Vulnerable to Stakes?

Everyone knows that vampires are vulnerable to stakes. On Buffy the Vampire Slayer, I am pretty sure there's a time a vampire accidentally gets a splinter in its finger and-- bam!-- he turns into a cloud of dust.

But why is this?

I am sure all kinds of different vampire stories have offered their own explanations and rationalizations. In the excellent 1998 British vampire techno-thriller Ultraviolet, the vampire-hunting task force uses "carbon bullets" as a modern upgrade to stakes, so apparently vampires are somehow vulnerable to organic compounds entering their body at high velocity.

Like much of modern vampire lore, it all goes back to Dracula. But also like much of modern vampire lore, it's much more based on someone's hazy memory of Dracula rather than anything actually in the novel.

I recently listened to an audio drama, Dracula's War, that was a sequel to a faithful adaptation of Dracula from Big Finish Productions (I have a review of the original here; I haven't written my review of War yet). There's one scene where Mina Harker and Van Helsing must fight their way through an army of vampires on a train, and so they are staking vampires left and right, turning them to dust.

This made me go, "hang on!" I thought this was supposed to be a faithful adaptation?

If you go back to Bram Stoker's novel, it's not that vampires are uniquely vulnerable to stakes. Here's the first time stakes are mentioned, when Jonathan Harker and Van Helsing are discussing what is to be done about Lucy now that she's a vampire:

“Do not press me too hard all at once. I am willing to accept. How will you do this bloody work?”
     “I shall cut off her head and fill her mouth with garlic, and I shall drive a stake through her body.” (210)*

Lucy is vulnerable to stakes in the same way that you or I are vulnerable to stakes: if you drive one through her heart, she dies. It's just that since Lucy is dead, this is the only thing she is vulnerable to.

If you pause and think about, it would actually be quite hard to drive a stake through someone's body. It's not the kind of thing you would get the force to do just by thrusting really hard with one in your hand. Indeed, it turns out to be pretty tough work. Harker tells us that Van Helsing took out

a round wooden stake, some two and a half or three inches thick and about three feet long. One end of it was hardened by charring in the fire, and was sharpened to a fine point. With this stake came a heavy hammer, such as in households is used in the coal-cellar for breaking the lumps. (221)

Then, Van Helsing gives the stake to Arthur Holmwood and tells him what to do:

“Take this stake in your left hand, ready to place the point over the heart, and the hammer in your right. Then when we begin our prayer for the dead — I shall read him, I have here the book, and the others shall follow — strike in God’s name, that so all may be well with the dead that we love and that the Un-Dead pass away.”
     Arthur took the stake and the hammer, and when once his mind was set on action his hands never trembled nor even quivered. Van Helsing opened his missal and began to read, and Quincey and I followed as well as we could. Arthur placed the point over the heart, and as I looked I could see its dint in the white flesh. Then he struck with all his might.
     The Thing in the coffin writhed; and a hideous, blood-curdling screech came from the opened red lips. The body shook and quivered and twisted in wild contortions; the sharp white teeth champed together till the lips were cut, and the mouth was smeared with a crimson foam. But Arthur never faltered. He looked like a figure of Thor as his untrembling arm rose and fell, driving deeper and deeper the mercy-bearing stake, whilst the blood from the pierced heart welled and spurted up around it. His face was set, and high duty seemed to shine through it; the sight of it gave us courage so that our voices seemed to ring through the little vault.
     And then the writhing and quivering of the body became less, and the teeth seemed to champ, and the face to quiver. Finally it lay still. The terrible task was over. (223)

It's hardly the clean, antiseptic transformation into dust! I mean, how else would you get a stake through someone's rib cage into their heart? It certainly isn't a thing one could do by one's self, with one's hands, in the middle of a battle! But nothing else will kill a vampire, for they are already dead.

And why do they turn into dust? You'll note that Lucy did not. Van Helsing says that this ought to happen to Dracula, according to Jonathan: "If the Count is there, Van Helsing and Seward will cut off his head at once and drive a stake through his heart. [...] The Professor says that if we can so treat the Count’s body, it will soon after fall into dust" (329). Why is explained later, when Van Helsing kills Dracula's vampire minions where they sleep in their tombs:

hardly had my knife severed the head of each, before the whole body began to melt away and crumble in to its native dust, as though the death that should have come centuries agone had at last assert himself and say at once and loud “I am here!”  (362)

Later, Dracula does turn into dust when he is stabbed with a knife (not a stake!) by Quincey at the same moment Harker slits his throat. It seems that the reason is the same for him as for his minions; when a vampire ceases to be Un-Dead, the decay that should have happened catches up to its corpse. Decay of days does little to Lucy, but the decay of centuries means that only dust is left of Dracula.

So vampires are not vulnerable to stakes-- it's just that they're invulnerable to almost everything else, because they're already dead.

Now, fine, adaptations can do what they want. But I do object to an adaptation that bills itself as faithful taking its cues from Buffy the Vampire Slayer and not the actual novel!

* All of my citations of Dracula are from the 2002 Case Studies in Contemporary Criticism edition from Bedford/St. Martin's, which reprints the text of the 1897 first edition.