Chlorine Gas, Mustard Gas
Chlorine gas and mustard gas belonged to that class of weapons that were not especially difficult to manufacture yet possessed formidable killing power.
Chlorine gas, after all, could be obtained simply by electrolyzing salt water.
Mustard gas was a little more complicated, but still far easier to produce than most other biochemical or poison-gas weapons.
There was a reason it had been used on such a massive scale during the Second World War.
In the Central Plains, however, electrolysis was impossible.
Still, if you have no teeth, you use your gums.
They might not be able to perform electrolysis, but chemical decomposition was another matter.
Thus the production process Hwi-yeom devised for chlorine gas and mustard gas ran as follows.
First: how to make chlorine gas.
React manganese dioxide (MnO2) with hydrochloric acid (4HCl) and you obtained manganese dichloride (MnCl2) + water (2H2O) + chlorine gas (Cl2).
Beneath the Poison Hall of the Sichuan Dang Family lay a fissure that endlessly welled with sulfuric acid.
That was why the clan had settled here in the first place.
And with sulfuric acid on hand, one could react it with salt to produce hydrochloric acid.
So under the Poison Hall there truly existed pools—not metaphorical ones—of sulfuric and hydrochloric acid.
All they needed, then, was manganese dioxide, and chlorine gas became possible.
Manganese dioxide—or rather the manganese ore itself (nowadays called manganese)—was extremely easy to come by.
The mineral known as pyrolusite had been used in ancient Rome to decolor glass, and medieval alchemists had employed it as an oxidizing agent.
Extracting manganese dioxide from pyrolusite was simple enough: grind the raw ore fine and wash it with water; the denser manganese settled nearby while the waste washed away. Repeat the process several times, filtering the settled powder through cloth, and high-purity manganese could be obtained.
And Sichuan, as it happened, was also a place where manganese was mined in enormous quantities.
Damn it, Sichuan again. I really ought to worship the place.
He had not planned it that way, yet Sichuan, Yunnan, and Guizhou were all regions where manganese was extracted in vast amounts. It was not something Hwi-yeom even needed to memorize the way he had the locations of vanadinite deposits. Why? Because you could dig it out the way people in Korea dug limestone.
Second: how to make mustard gas.
To produce mustard gas one had to react ethylene (C2H4) with sulfur dichloride (SCl2).
Ethylene could be drawn off by dry-distilling coal.
Dang Unhwa had already dry-distilled coal and passed the resulting coal gas through copper pipes running through cold groundwater, cooling it to obtain toluene, which he had then used in the bottle-shaped fire arrows.
Ethylene could be recovered by taking the coal gas left after the toluene had been extracted, passing it through activated charcoal so that the sticky, coal-tar-like substances adsorbed onto it, collecting that residue, and boiling it.
In truth, coal gas produced by dry distillation contained, besides toluene, benzene, phenol, xylene, and coal tar, also methane, carbon monoxide, hydrogen, and the rest. During the toluene extraction, however, the benzene, phenol, xylene, and coal-tar fractions were all filtered out, leaving ethylene, methane, carbon monoxide, and hydrogen.
Of these, ethylene had the greatest density and therefore adsorbed more readily onto porous materials such as activated charcoal than the others did.
Put simply, it was stickier than the rest and got caught in the filter.
So one passed the coal gas through charcoal, collected the sticky soot that came out, and boiled it to obtain ethylene.
That done, the next step was to make sulfur dichloride.
The method was even simpler. Take the chlorine gas already prepared and react it with sulfur vapor obtained by burning sulfur; sulfur dichloride gas formed at once. Then pass that gas through metal pipes running through cold water to liquefy and collect it.
React the ethylene and sulfur dichloride thus obtained, and—mustard gas complete.
Easy, right? Well, no. It was difficult, complicated, and wildly inefficient by modern standards… yet for the present it was the best they could manage, and Hwi-yeom was confident that only the Sichuan Dang Family in all the realm could pull it off.
“These substances are extremely dangerous, and we also have to worry about disposing of the by-products, so we must approach this with care.”
Hwi-yeom summoned Construction Department Manager Gwak Do, Metallurgy Department Head Han Cheol, and Dang Unhwa, and began pushing construction of the production facilities he had designed.
At the same time he started mobilizing the full resources of his affiliated conglomerates to make every necessary preparation.
The very first task he set in motion was prospecting for mines from which manganese ore could be extracted.
Even though manganese was abundant in nature and commonly found throughout Sichuan, Hwi-yeom still scattered enough money to hire every prospector in the region in order to locate commercially viable manganese deposits in short order.
Prospectors who saw the recruitment notice promising a full year’s wages in a single lucky strike came running with eyes as round as saucers.
“Pyrolusite? What’s that?”
“I heard it was chi-sa.”
“Ah, that stuff? The stone powder potters mix in to color their ware?”
“Seems so.”
“Why do they call it pyrolusite, then?”
“How should I know? They say the Young Master named it that.”
“Ah, if the Young Master says so, then that’s what it is.”
Manganese was already a metal used in firing pottery, so Hwi-yeom’s recruitment drive yielded swift results.
Before long, pyrolusite veins were discovered simultaneously in several places.
Hwi-yeom ordered Gwak Do to build extraction works capable of refining high-purity manganese from the ore. Gwak Do took one look at the blueprints he had received and began to grumble.
“Young Master, why do we need a separate reservoir just to hold the water we wash the rocks with? Can’t we just let it run into the river? This only makes the construction longer and more complicated.”
Hwi-yeom’s design called for a riverside waterwheel to crush the pyrolusite, then for the wash water used to separate manganese from waste to be directed not into the river but into a large, specially prepared sedimentation pond.
That meant building both the water channels leading to the pond and the pond itself, so of course the schedule grew long and complex.
For someone who had never heard of the evils of heavy-metal pollution, the complaint was only natural.
Even in the modern age, when those evils were well known, unscrupulous companies still quietly dumped the same water into rivers on rainy days—or on ordinary days—to save purification costs. So the reaction was hardly surprising.
Instead of delivering some high-flown lecture on protecting the ecosystem (which, from Gwak Do’s perspective, would have been pure fantasy), Hwi-yeom gave him a more practical reason.
“Pyrolusite is toxic too. If people drink the water you dump, they’ll get sick. Do you want to hear people saying the Sichuan Dang Family poisoned the river the people of Sichuan drink from?”
“I’ve lived this long without ever hearing that chi-sa was poisonous. Then shouldn’t all the potters have died of it long ago?”
“Manager Gwak, do you know more about poisons than I do?”
“Well, no, but…”
“Got free time? Want me to pile more work on you?”
“I’ll start at once!”
Faced with a rare display of high-handed firmness from Hwi-yeom, Gwak Do fled with an expression that said he had just touched a hot stove.
Hwi-yeom watched his retreating back for a moment, then let out a quiet sigh.
“I can hardly destroy the foundation I’ve built with my own hands.”
Collect the heavy-metal wastewater in the sedimentation pond and scatter lime powder into it; the alkaline components of the limestone would neutralize the waste and precipitate the manganese ions. Once the precipitate settled, open the sluice and send the clear water on to a second purification stage.
That second stage was an artificial wetland thick with aquatic plants—reeds, cattails, and the like. The plants would take up manganese through their roots while microbes broke down the contaminants.
The carefully treated water could then be discharged; the remaining sludge would be dried and landfilled.
By these means they could keep heavy-metal pollution from fouling Sichuan’s rivers and groundwater as much as possible.
“It’s not as if any rival company in this era can compete with me on the economics of manganese production… and the environment of the land I live on is a matter of the first importance.”
Thanks to Hwi-yeom’s refusal to compromise, construction would not finish until late summer.
Had he known that the Chagatai Khanate would invade in late autumn, he might have hurried a little more… but even so, it would not be too late.
While the manganese plant was going up, the Innovation Hall joined forces with the Poison Hall to construct a new building capable of producing chlorine gas and mustard gas.
To protect the clan from any possible gas leak, the structure was raised on the same mountain as the main estate yet placed lower in a valley where the wind could never carry gas toward the living quarters. They named it the Poison Gas Hall.
Unlike the experimental TNT and smokeless-powder workshops hidden deep beneath the Poison Hall to keep them from Baek Beon’s eyes—because their very existence and methods were classified—this building could stand in the open without trouble.
It was a place that researched poisons; they would have an answer ready for the Emperor.
Besides, building an underground laboratory for poison gas, no matter how good the ventilation, was likely to end as a novel form of suicide.
And so, while manganese mines, production and refining facilities, wastewater treatment works, and the poison-gas plant rose one after another,
the Innovation Hall steadily increased production of flintlock muskets.
When these were stockpiled at the Dang estate instead of being sent at once to the imperial court, Baek Beon found it strange. Hwi-yeom explained that the Chagatai movements looked ominous and that the stockpile was a precaution.
“In short, if war breaks out you mean to arm Yunnan and Sichuan with these?”
It was a dangerous idea. Depending on how one looked at it, they could be accused of plotting rebellion and have no defense.
So Hwi-yeom chose a frontal assault.
“Inspector, with the intelligence network of the Dongchang, could you look into Chagatai’s movements for us? If my worries prove groundless, I will send these muskets to His Majesty at once. But if they truly show signs of invading, then these weapons will be needed to protect His Majesty’s subjects.”
“…The very fact that you manufactured weapons and did not send them immediately is already dangerous.”
“Yet if, merely to prove the Dang Family’s innocence, we endanger the lives of the people of Sichuan and Yunnan, would that not also, in the larger view, be disloyalty to His Majesty the Emperor?”
Baek Beon sighed.
“Young Master, you always force me into dangerous choices. I constantly feel as though I’m being drawn in.”
“You’re imagining things. Please trust my loyalty.”
“…There’s a saying, you know. ‘It is easier to ask forgiveness than permission.’”
Baek Beon pressed his fingers hard against his furrowed brow, looking thoroughly put-upon.
“If things go wrong, I shall report that the entire Dang Family concealed the manufacture of flintlock muskets from me. Are you still fine with that?”
“If we explain that the Dang Family’s technicians, filled with righteous fury at the news that those barbaric nomads were coming, stopped eating and sleeping and stamped out a huge quantity of flintlock muskets in a short time… I rather think you might let it slide…?”
Baek Beon’s mouth fell open for a moment as he pictured the scene; then he gave a snort of incredulous laughter.
“Why does that feel like something that happens all the time?”
“Come now, you’re just imagining it.”
While the Dang Family’s principal organs were thus absorbed in war preparations, the Inner and Outer Halls were equally frantic for an entirely different reason.
In particular, Eun Seol-ran—who normally spent most of her time in leisure—was raising the loudest voice and busying herself the most.
The reason was simple.
“The wedding is right around the corner! Why is the preparation so sluggish!”
Naturally, it was because of the wedding preparations for her son—preparations that even the groom himself was paying no attention to whatsoever.