Here's How The Assassin's Teapot Really Works

Good news: Today you get to learn how to kill someone with a teapot. And no, we don't mean taking it and bashing it against someone's head. We mean killing someone with the tea in the pot. But if you want to skip the explanation, you can just buy a murder vessel on Amazon, Walmart, Etsy, and loads more places. Also and relatedly: Have medical examiners been keeping an eye out for odorless, colorless, poisonous liquids while conducting autopsies related to mysterious deaths between squabbling spouses?

Anyway, "assassin's teapots" — as they've been dubbed — do exactly as the name suggests. Imagine you're sitting in a Victorian drawing room engaged in overly polite conversation with Sir Paddington Whatever-Whatever and suddenly he keels over while taking a sip of his Darjeeling. Splat he goes, and some suspicious relative gets his inheritance. "But Sir Paddington was drinking the same tea as everyone else!" you say, pointing to the seemingly innocuous teapot. You even pick it up, tilt it, and pour out the liquid. How come the tea killed him and not the other frilly-dressed folks in the drawing room?

Ultimately, it's pretty simple. You know how you can cover one end of a straw to keep the liquid inside? Assassin's teapots work just the same way, as science dude Steve Mould explains on YouTube. There are holes on the outside of the pot and separate chambers inside for tea and poison. Plug one hole and out comes the tea. Plug another and out comes the poison.

So yeah, assassin's teapots are definitely more "Oh" and less "Oh!" (exclamation point) when you learn how they work. They're the weapon of choice for a game of "Clue," not a Sherlock Holmes murder mystery. Nonetheless, some would-be assassin deserves a bit of praise for discovering what all children with straws have discovered and then applying it to the venture of ending human lives. That last part requires effort, because assassin's teapots have to be crafted for the express purpose of containing multiple chambers that hold multiple liquids, with each compartment having a hole on the surface that a person can plug while pouring.

In scientific terms — as the aforementioned Steve Mould points out — assassin's teapots operate using two fundamental principles: atmospheric pressure and surface tension. Atmospheric pressure is the force that air exerts on something. When you plug one end of a container like a straw, you create a seal that prevents new air from getting inside. The pressure of air outside the container is greater than the pressure inside, and so in the case of an assassin's teapot, the liquid (tea or poison) stays inside the pot. Plus, gravity pulls down on the fluid to help keep it in place. Gravity also works hand in hand with surface tension, as seen when a leaf floats in a puddle. This happens because water molecules on the surface strongly adhere to neighboring water molecules to form a layer. Hence the assassin's teapot's plugged hole trick. 

It's a little hard to pinpoint precisely who first devised the assassin's teapot, because, you know, it was seemingly supposed to be a secret murder weapon. But we do know that similar types of "trick vessels" have been used forever by stage magicians for the purpose of wowing audiences with impossible feats of pouring and drinking. The "inexhaustible bottle" is one such trick vessel that operates on principles very similar to an assassin's teapot. 

Just like an assassin's teapot, you make a separate chamber inside a vessel connected to a hole to the outside — this controls which chamber the liquid pours out of. This means that if you give the bottle to someone who doesn't know the trick, it's not going to work. Then again, the same thing is true for the assassin's teapot. The aspiring killer is the one who has to do the pouring, which would be a major clue in a murder mystery game.

At this point, such tricks are so well-known that there's even websites like Penguin Magic containing purchasable lessons that show how to demonstrate trick vessel tricks for an audience. Such sites reveal that the inexhaustible bottle also goes by other names like Think-a-Drink, Any Drink Called For, and Magic Port. It's possible that someone might have based the assassin's teapot on these kinds of vessels, rather than the other way around. Then again, the assassin would never tell.