Poison, he cried!

Can you really develop an immunity to poison by taking little bits of it at a time?

I'm not talking about you, Christian.

Okay, what are you driving at, Fred? you ask. You’re either expecting to be poisoned or you want to kill someone by sharing a drink full of poison that you’re immune to, right? Like iocane powder in The Princess Bride? Or like in that story “Fly Paper”by Dashiell Hammett?

To which I say, “You can’t prove anything!”

Yeah, that Hammett story didn’t turn out too well for the would-be killer. The plot hinged on the fact that flypaper contained arsenic at the time, so it didn't turn out well for the flies, either, I imagine.

I got to thinking about this poison immunity thing not because of any lethality I wished to accomplish or expected in my own life, but rather from a rumor I thought I’d heard that apple seeds contain arsenic. Like Bill Clinton, I have the longstanding habit of eating everything from the apple but the stem. (Although he claims he only does it once in a while, the weakling.) So does that mean I am immune from arsenic poisoning? Since arsenic is a metalloid, can you even eat your way to immunity from it? Or is like taking iron pills to become immune to stabbing? To the Internet!

As Snopes tells us, apple seeds contain amygdalin, a cyanide compound, so I was wrong about the arsenic. I think my confusion came from the fact that apple seeds taste nutty, like an almond, and I thought arsenic was the bitter almond smellin' stuff mentioned on TV detective shows; actually it was cyanide. Which actually is sorta crap too, as it turns out.

But never mind; the question now becomes, am I immune to cyanide poisoning?

Probably not. Apple pits usually pass through the system undigested because of the hard outer shell. And they’re kind of small. So there's very little cyanide in there, even if you could use them to build up an immunity.

All right, so can you really even become immune from poison at all? I’m sure you’re all immediately thinking of A. E. Housman’s immortal poem “Terence, This Is Stupid Stuff,” wherein he defends his pessimism in the last section:

There was a king reigned in the East:
There, when kings will sit to feast,
They get their fill before they think
With poisoned meat and poisoned drink.
He gathered all that springs to birth
From the many-venomed earth;
First a little, thence to more,
He sampled all her killing store;
And easy, smiling, seasoned sound,
Sate the king when healths went round.
They put arsenic in his meat
And stared aghast to watch him eat;
They poured strychnine in his cup
And shook to see him drink it up:
They shook, they stared as white’s their shirt:
Them it was their poison hurt.
–I tell the tale that I heard told.
Mithridates, he died old.

There were a lot of Mithridateses; Mithridates V was poisoned to death by persons unknown, so legend has it that M6 made himself immune to poison by taking little bits at a time, as Housman wrote. The story goes that even when he wanted to poison himself after defeat by the Romans, Mithridates’s immunity prevented it.

A decade ago the ever-interesting Straight Dope column addressed the question as to whether you can really build up an immunity to poison, and the answer is: Maybe. The column cited reports of arsenic eaters who claimed immunity, and herpetologists who claimed immunity to snake venom. It also noted that it may be possible to become immune to the less awful poison in poison ivy.

But no, it looks like the idea of developing an immunity to man-killing poison is a mostly myth. I had better stay away from eating anything for breakfast that requires a Safety Data Sheet.

I’ll stick to bacon and coffee. They may kill me, but it will take a long time.