“Ok soldier, your assignment is to pee - right there, give it a few months, and hopefully
some other gunpowder will show up in the meantime…”
(Splash) When the American Revolutionary War started in 1775, things got a little weird
as the rebel colonist supply of gunpowder began running low.
See, the main chemical compound in gunpowder -- potassium nitrate -- is not that common
in nature in the United States.
And because they couldn’t order it off of Amazon the soldiers said, “hey let’s make
it ourselves!”
So they mixed pee with ash, leaves, sticks and soil.
Strange, gross, but actually kinda smart.
With the help of bacteria, ammonia from pee reacts with oxygen to form nitrates that bond
with potassium ions in the ash and soil and, there ya have it, potassium nitrate!
Potassium nitrate is so crucial because it makes up 75% of gunpowder.
The rest is 15% charcoal and 10% sulfur.
We’ll now refer to this mixture by its more specific name: black powder.
When you ignite black powder it starts a combustion reaction.
This kind of reaction requires two things: a fuel source and an oxidizing agent.
In this case, the fuel source is charcoal, which is a bunch of carbon atoms all strongly
bonded to each other.
Potassium nitrate supplies the oxidizing agent--oxygen.
When charcoal heats up, its carbon-carbon bonds are broken and new bonds are formed,
releasing some energy.
This energy raises the temperature of the potassium nitrate and it splits apart, releasing
oxygen, which keeps the reaction going until all the charcoal is used up.
All this happens in a few thousandths of a second.
Potassium nitrate removes the need for atmospheric oxygen, so black powder can ignite in a closed,
oxygen-depleted space, like the barrel of a gun.
This is why you can’t smother fireworks to put them out but you can smother a campfire.
A campfire needs external oxygen--fireworks have it built in.
So if you were just looking for something to burn you could actually stop at charcoal
and potassium nitrate.
But it’s the sulfur that makes black powder such a powerful explosive.
It has a low melting point so, once the reaction starts, it heats up really quickly and is
ready to accept the oxygen from the potassium nitrate.
This creates sulfur dioxide which acts as another fuel source, ultimately making the
combustion of black powder go much, much faster.
The gases released when black powder combusts take up way more space than the solids that
they came from.
Pressure builds and, before you know it, [BOOM] there’s an explosion.
When black powder is trapped in a totally sealed off space, you’ve got a bomb.
When it’s trapped in a space with just a small hole, you’ve got a rocket.
Throw it in a mini-cannon with a bullet and, hey, you’ve got a gun.
Which brings us back to the American Revolutionary War and that delightful pee, soil, ash slurry.
Unfortunately for colony troops that stuff took months to marinate and still didn’t
help them make enough gunpowder to win a war.
So, they relied heavily on help from the French and a raid of Bermuda’s black powder supply,
a secret mission orchestrated by co-conspirators Bermudian merchant and Militia officer Henry
Tucker and founding father Benjamin Franklin.
And the whole “mix pee/soil to make potassium nitrate” thing didn’t totally disappear
after the American Revolution.
There are accounts of Confederate troops collecting urine from the bedpans of townspeople to overcome
a gunpowder shortage in the South.
Even Though black powder was essential for American troops to win the war,
that doesn’t mean it was ideal.
The crazy plumes of smoke it released made it impossible to see the battlefield
and corroded soldier’s guns.
So when something better came along people were like YES PLEASE GIMME THAT.
That thing was smokeless powder.
Smokeless powder is a general term that covers a combination of a bunch of different chemicals,
but basically they’re a class of crazy-powerful explosives, their components able to break
down and explode faster than the speed of sound.
Although smokeless powder isn’t totally smoke-free, it produces
almost no smoke compared to black powder.
That’s because smokeless powder reactions release mostly gases whereas more than half
of the products of black powders are solids, including gun-corroding, battlefield-clouding
potassium sulfide.
Although black powder is still used for things like fireworks, specific types of mining,
and Civil War reenactments, there’s only one black powder factory that exists today
in the United States.
All of the others have, sort of exploded, or closed often due to safety concerns.
Smokeless powders were also super dangerous in their early days.
For example, nitroglycerin.
See these three groups attached to its carbon backbone?
These oxygens act as oxidizers, which means nitroglycerin
can explode on its own.
It’s not like black powder which needs a separate compound
potassium nitrate--to supply the oxidizer.
Nitroglycerin was too dangerous to use on its own, so researchers worked to find compounds
that would stabilize it.
One of those researchers, Alfred Nobel, THE Nobel Prize Nobel [image], did so in the mid-1800s,
which led to the creation of dynamite.
Smokeless powder is now not only less smoky and more powerful than black powder, it’s
also easier to manufacture without worrying about -- ya know, your factory exploding.
Have you ever been to a Revolutionary war or Civil War reenactment?
I certainly have not.
But I want to know, how smoky was it?
Let us know in the comments, and we’ll see you next week.
Surely, there’s got to be one of you that’s been.
Yes.
Yeah.
You.
Sir.
Sir?
Please comment. Thank you.