As Arthur walked through the halls outside the great hall, his thoughts shifted toward one of his key experimental projects. I should check on the nitre bed and see if I could begin the crystallization process. Last time I inspected it, the process was still in its early stages. But now, roughly after 4 months, I should be able to extract a small sample even if it is less concentrated.
Arthur knew that the quality and concentration of the potassium nitrate wouldn’t be optimal yet. Normally, the decomposition process in a nitre bed requires at least six months or more to reach full potency. The longer the organic matter broke down, the more concentrated the yield.
Arthur then thought to himself, However, I wasn’t mass-producing it just yet. This was merely a test to determine if the method was working in this world. Besides, since it is in a different world, environmental factors might influence the speed of decomposition differently here. It’s best to check early rather than wait blindly.
With a slight change in course, Arthur turned away from the path leading to the library and instead made his way toward the project site. Ken followed silently behind him, keeping a watchful eye on their surroundings.
Upon arrival, Arthur saw Clint overseeing the site, where several large stone pits had been repurposed as containers for the potassium nitrate production process. The sharp, overpowering ammonia stench from the last visit had faded somewhat, now replaced with an earthy, musty odor mixed with a faint hint of rot. It was an improvement—less offensive, though still far from pleasant.
Clint noticed Arthur approaching and quickly stepped forward to greet him. "Your Majesty, it is an honor to meet you. Have you come to check out how we are doing?."
Arthur nodded as Clint led him toward one of the stone pits. Peering inside, he could see that the original mixture of organic materials—straw, manure, and decomposing plant matter—had broken down significantly. What was once a dense, pungent heap had transformed into a drier, crumbly, soil-like texture. Some fibrous remnants still remained, but the majority had decayed well.
Arthur’s eyes gleamed with interest. The decomposition is faster than I anticipated. If left undisturbed for another month, the concentration of potassium nitrate would increase further, making extraction more efficient. Still, I should attempt a small-scale leaching test today to confirm that the nitrification process is working.
Arthur turned to Clint and said, “I’ll show you how to extract potassium nitrate. That way, when it becomes more concentrated in the future, you’ll know exactly how to harvest it.”
He continued, “Since it's still early in the process and nitrous earth is yet to mature, the potassium nitrate concentration is lower. I might not be able to extract as much potassium nitrate as I would later on.”
Clint nodded in understanding and called over the other members. Curious and eager to learn, they gathered around to observe Arthur's method, keen to finally see the extraction process he had often spoken about.
Arthur crossed his arms, surveying the prepared workers. “We’ll start by collecting the decomposed material—what we call nitrous earth. This is where the nitrates have formed.” He gestured toward the pit. “Gather a manageable amount and place it in that wooden trough.”
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The workers hurried to comply, shoveling the dry, crumbly substance into a long, shallow trough lined with cloth. The air carried a faint, musty scent, the ammonia odor now greatly reduced.
“Now,” Arthur continued, “we’ll leach the nitrates out using hot water. Pour heated water over the nitrous earth, but do it gradually.”
A worker carefully ladled steaming water over the material, soaking it thoroughly. Arthur pointed to the bottom of the trough, where a small spout allowed the liquid to drain into a clay basin.
“This is the leaching process,” he explained. “Hot water dissolves the potassium nitrate and other soluble salts, drawing them out of the decomposed matter. The liquid that collects below is called the lixivium—it contains the nitrates we want.”
As the cloudy liquid pooled in the basin, Arthur dipped his fingers into it and rubbed them together. “A good lixivium should feel slightly gritty and leave a faint residue when dried. This means it holds the dissolved potassium nitrate.”
"Once enough liquid had been collected," Arthur moved on. "We need to purify it. Strain the lixivium through cloth to remove debris, then transfer it to the cauldron for boiling.”
A few workers filtered the liquid through layers of fine cloth into a large iron cauldron set over a controlled fire. Arthur watched as the water began to simmer.
“Now we boil,” he said. “Evaporating the excess water concentrates the solution, allowing the potassium nitrate to separate more easily. But be careful—we must keep the heat steady. Too much heat, and impurities will mix in.”
The workers stirred gently, watching as the liquid gradually reduced. Foam and scum rose to the surface, which Arthur skimmed off with a wooden ladle.
After some time, Arthur nodded in approval. “Now, we let it cool slowly. As it cools, potassium nitrate will crystallize out of the solution.”
The cauldron was removed from the fire and set aside. Everyone watched as, little by little, tiny white crystals began forming along the sides of the vessel. Arthur scooped a small handful and held them up.
“This is what we’ve been working for,” he said, showing the crude potassium nitrate. “It will need further refinement, but this proves the process works.”
Clint and the others examined the crystals with awe.
Arthur dusted off his hands. “Store this batch carefully. Over time, as the nitrous earth matures, we’ll extract a greater yield. For now, we are just testing if it would work or not.”
Arthur cast one last glance over the pit, a sense of satisfaction settling over him.
This is a success, he mused. If I allow the nitrous earth to mature further maybe about a month or so, the yield will increase significantly. Now that potassium nitrate is within reach, I must accelerate efforts to locate sulfur.
Turning back to the gathered workers, he addressed them with a firm but encouraging tone. “Now that you all understand the process of extracting potassium nitrate, focus on maintaining the moisture in the nitrous earth. This will allow it to mature further, increasing its concentration and yielding a greater amount of potassium nitrate in the future.”
“Yes, Your Highness. We will continue as instructed,” the workers responded in unison.
Clint, still intrigued, hesitated for a moment before stepping forward. “Your Majesty, if I may ask… what exactly is this potassium nitrate used for?”
Arthur considered his response before answering, “It has several uses. One of them is as a fertilizer—it helps crops grow stronger and more plentiful.” He paused, then added, “But that is not its primary purpose.”
Clint frowned slightly. “What is the primary purpose?”
Arthur’s gaze sharpened. “Gunpowder.”
The unfamiliar word hung in the air, drawing curious murmurs from the group.
Clint furrowed his brow. “Gunpowder? What is that?”
A small smirk played at Arthur’s lips. “I like your curiosity, Clint. But for now, think of it as a tool—one that will strengthen this kingdom in ways you cannot yet imagine.”
Though unsatisfied with the vague answer, Clint bowed respectfully. “If you say so, Your Majesty.”
Arthur gave a final nod. “Continue your work. Know that what you are doing here will shape the future of this kingdom.”
With that, he turned and strode away, Ken falling into step beside him. As he made his way back to the library, his thoughts drifted.
Even if I tried to explain gunpowder to them now, they wouldn’t truly understand. They will only realize its significance once it’s complete—once they see its power firsthand.