This post was inspired by an Anime that I am currently watching called Drifters. It is a show where several historical figures are transported into a different world inhabited not just by humans but also fantasy creatures like Elves, Dwarves, Hobbits, Giants, Orcs, Goblins and Dragons.

In one of the episodes, one of the protagonists Oda Nobunaga (Yes I found it weird that the self-proclaimed Demon of the Six Heavens was a protagonist here as he is usually painted as evil) nonchalant says to put the bodies in a pit to make gunpowder. I had a wait, what moment!

Source

Making gunpowder out of dead bodies. It took some time for that to sink in.

I like reading about warfare and I have some basic knowledge of how gunpowder is created and how it changed the landscape of war forever.

Chemically it's formula 10KNO3 + 3S + 8C and its reaction is 10KNO3 + 3S + 8C → 2K2CO3 +3K2SO4 + 6CO2 + 5N2

To refresh your mind of high school chemistry for most of us here are the following component:

C - Charcoal
S - Sulfur
KNO3 - Potassium Nitrate also known as saltpeter

Nobunaga was a feudal warlord that used gunpowder in his arquebus army to unite a war-torn Japan during the Sengoku period. So corpses would be plenty during that time period.

Making gunpowder from corpses

So researching how gunpowder was being made during the Sengoku period and how guns rose to prominence during this turbulent times I found that it was the Portuguese who sold two muskets to Tanegashima Tokitaka.

It was Nobunaga in 1549 who ordered 500 matchlock rifles be made for his army and was a deciding force in his campaign for unification.

Although it was said that Japanese longbows could shoot farther, faster and more accurately but shooting a bow looks easy but takes a lot of practice and experience to be good at it. The samurais although romanticized as being skilled swordsmen in using their katanas were often masters of the bow and used this primarily in warfare.

It took a lot of time and training for these archers to be good while a matchlock rifleman could be trained with less time and effort to be effective in battle.

A gun without gunpowder is just a pipe and so the creation of gunpowder is a vital part of the war effort.

Huge places were created to mix in the necessary ingredients.

Charcoal could be easily obtained, Sulfur could be mined from volcanic areas but saltpeter was a bit more difficult because it had a very specific condition that needed to be met before it would form.

Making saltpeter

So going back to the Anime drifters they hauled the bodies and dumped it into the pit which had urine, manure, straw and grass in it. Nobunaga with a devilish grin states that after some time it will become black powder (gunpowder) but he also needs sulfur and orders the female buxom mage to get him sulfur.

So what is going on with that pit. Reading on how saltpeter is made there were two lower tech ways to make.

French method
Niter-beds are prepared by mixing manure with either mortar or wood ashes, common earth and organic materials such as straw to give porosity to a compost pile typically 4 feet (1.2 m) high, 6 feet (1.8 m) wide, and 15 feet (4.6 m) long.[18] The heap was usually under a cover from the rain, kept moist with urine, turned often to accelerate the decomposition, then finally leached with water after approximately one year, to remove the soluble calcium nitrate which was then converted to potassium nitrate by filtering through potash.

Swiss method
A process using only urine and not dung, referring to it as the Swiss method. Urine is collected directly, in a sandpit under a stable. The sand itself is dug out and leached for nitrates which were then converted to potassium nitrate using potash, as above.

I found this video of making it using urine.

[Youtube channel - Cody's lab]

It is a long process where urine needs to be constantly added so the mixture does not dry out and the bacteria given sufficient material to decompose usually straw but in Nobunaga's case were the dead bodies.

It would be then filtered and strain, the liquid boiled leaving a whitish crystal powder. This is then mixed with the charcoal and sulfur and pressed into pellets giving it enough space to efficiently burn and you have gunpowder!

It modernized warfare and replaced many weapons like swords and spears and became the weapon of choice for waging war from East to West.

I remember a history lesson of when the Philippines were colonized by the Spaniards they used the 3 G's, Guns, Gold and God.

It was a minor thing explained in the anime but one that made me curious if it was possible to make gunpowder from corpses.

I hope you learned something cool.

Sources:

GUNPOWDER FROM URINE, FIGHTING A GORN
Firearms of Japan
Taboo's gunpowder plot: can you really make explosives from manure?
Potassium nitrate