Sky Curtain: My Great Qin must have an aircraft carrier!

The principal changed the picture to one with seawater, an iron pot, and a filter, along with arrows and labels.

To make fine salt, you first need to extract coarse salt. If we want to get rich quickly, today we'll teach you the solution purification method!

[First step: secretly fill two buckets with seawater at the beach, then filter out impurities with a strainer before pouring it into an iron pot and heating it.]

Boil over a high flame for forty-nine days until the water evaporates; this is coarse salt!

The people who had been listening intently just moments before were now stunned.

"What? We have to endure forty-nine days?"

"My goodness, how much firewood will this take? Even if you tore down my house for firewood, would that be enough?"

"Did the deity get it wrong? Forty-nine days is enough time for the daylilies to turn cold!"

The people were full of doubts and felt that this method was completely unreliable.

However, the emperors and generals, upon hearing this number, revealed a knowing look.

"This gentleman is quite interesting; he deliberately makes mistakes so that people won't actually learn them."

"Write down all the other steps and let the Ministry of Works verify them. We'll figure out the real time ourselves."

Clearly, the "forty-nine days" is not what it sounds like literally.

It's either some kind of code, or it's something deliberately said to discourage poor people!

The real core technologies are definitely yet to come!

The light and shadows shifted across the sky, and the bald principal, holding a pointer, banged the blackboard loudly.

Of course, if you have enough time, you can leave it in the sun to dry.

Dissolve coarse salt in water, let it stand for a few days, then remove the top layer of brine. Boil this brine several times to obtain relatively clean coarse salt!

[But it's not safe to eat yet. It contains magnesium chloride and other impurities that are harmful to the body, so it cannot be consumed directly!]

"Magnesium chloride?"

Ying Zheng frowned and looked at Li Si, who shook his head and looked at Zhao Gao, whose legs trembled as he looked at the floor tiles.

The three of them combined couldn't explain it in a single word.

"Don't worry about the name, just remember the method," Ying Zheng quickly decided.

The civil and military officials bowed their heads, their wrists hovering in the air, afraid of missing a single word.

[Next comes the most crucial step: purification. I'll teach you two methods!]

First, let's start with the simplest method: purifying soy milk! Soy milk can react with heavy metal ions to form precipitates.

On the screen, milky white soy milk is slowly poured into a pot of murky brine.

We scoop out these sediments, then boil the top layer of brine to crystallize it, which produces the finished fine salt.

Soy milk? You mean the kind of soy milk made from ground soybeans?

The people of the world looked at each other in bewilderment.

"Goodness, we grind soybeans every day at home. Why not just plant a few more acres of soybeans next year?"

"Isn't this...wasn't this a waste of food?"

"You idiot! If it were just salt, this little bit of soy milk wouldn't matter!"

[The second method is to find the remaining wood ash in the stove, put it in water and let it settle. Then scoop out the clear water from the top, pour it into a pot and stir constantly. You will then see flocculent sediment!]

[Then boil the top layer of brine to crystallize it, and you're all done! Look, fine white salt has appeared!]

The bald principal reappeared, making a victory sign with his hand and beaming.

"Fine salt purification, the advantage lies with me, get out of class dismissed!"

boom!

When the last two words were uttered, the entire world erupted in jubilation.

This complete process, with its detailed steps, looks... like it really works!

Emperors of all dynasties could no longer sit still, and imperial edicts were issued one after another like snowflakes.

"Order the Ministry of Works to summon all master craftsmen! Prepare seawater, soy milk, and wood ash!"

"Seal off the western suburban camp and establish it as the Royal Salt Production Bureau! Anyone who trespasses will be executed without mercy!"

"All those involved in salt production will live and eat in the camp. Anyone who dares to divulge even a single word will have their entire family executed!"

A salt-making competition that transcends time and space has quietly begun.

Thanks to the bald-headed principal's clear and concise explanations, and the fact that the most outstanding craftsmen from various dynasties were mobilized, the results came much faster than expected.

Just a few days later, the first batch of finished products was placed on the desks of various emperors.

Inside Xianyang Palace.

When the eunuch presented a small dish of fine salt with trembling hands, everyone held their breath.

Ying Zheng didn't have anyone test the poison; he simply reached out and pinched off a small amount, putting it in his mouth.

Salty, purely salty.

There is no bitterness, no off-flavors, only the purest freshness!

He closed his eyes, and when he opened them again, his eyes were filled with an uncontrollable fervor.

"Excellent! What a wonderful magical technique!"

This is not salt; it is the cornerstone that stabilizes the hearts and minds of the six states, and the powerful tool that brings the world under Qin's control!

"Your Majesty, the method of sun exposure mentioned by Tianmu can greatly reduce the consumption of firewood."

Li Si immediately cupped his hands in greeting and said, "I suggest that salt fields be opened up on the coast of the East China Sea, and seawater be diverted into the pools to replace the fire with sunlight."

Ying Zheng didn't rush to answer, but instead picked up another pinch of salt and rubbed it between his fingertips.

"Meng Tian".

"Your subordinate is here!"

"You shall personally go and select a site in Qi and transfer two thousand convicts to build a salt lake."

Meng Tian accepted the order and left.

Ying Zheng stood with his hands behind his back, staring at the white salt for a long time.

The hearts of the six states cannot be subdued by killing, but a bowl of fine salt can soften even the hardest bones.

Once ordinary people can afford cheap salt, who will talk to you about the grand cause of restoring the nation?

-

The Great Han Dynasty, Weiyang Palace.

Liu Che held the bowl of fine salt, turning it over and over several times, before finally sticking out his tongue and licking it.

"Wow."

He picked up the dish of fine salt and waved it at Wei Qing.

"Zhongqing, you told me before that 300,000 troops was the limit."

Wei Qing's brow twitched, vaguely sensing that the emperor was about to say something rather unreliable.

really--

"With this salt, can we support another 100,000 people? If we build a few more salt fields, can we support another 100,000?"

"Five hundred thousand! Five hundred thousand is enough! I will personally lead the army beyond the Great Wall and let the Xiongnu know what it means for karma to be cyclical!"

Wei Qing opened his mouth, wanting to say that the algorithm was too crude.

Raising an army involves more than just salt; it also includes provisions, armor, horses, and so on.

But seeing Liu Che's expression, he swallowed back the words he was about to say.

Alright, let's make His Majesty happy for a while first.

Emperor Wu of Han (Liu Che) shared the same idea as Emperor Yongle (Zhu Di) during the Yongle era.

The Northern Expedition against the Mongols required money, the construction of the new Beijing city required money, and Zheng He's voyages to the Western Ocean also required money.

The national treasury's meager funds are simply not enough for his extravagant schemes.

He desperately needs the money!

"The Ministry of Revenue and the Ministry of Works shall work together to establish the Royal Salt Administration. The method of salt production shall continue to be improved."

"You've mastered the ratio of wood ash to soy milk, and the control of the heat!"

Throughout history, whether wise or foolish rulers, once they tasted the fine salt, none of them ever wanted to return to the past.

Upon receiving the fine salt, Emperor Jiajing remained silent, dismissed all the palace servants, and sat alone in the alchemy room for a long time.

Zhao Gou tasted it and that very night ordered the entire imperial kitchen to replace all the salt with fresh salt.

Even the princes who were lying on the dragon throne, indulging in a life of leisure and waiting to die, showed a rare interest in politics.

……

"Burp~"

In a corner of the cafeteria, Lu Li let out a satisfied burp and put down his chopsticks.

Braised chicken rice, forever the best.

I casually clicked on the comments section, and sure enough, it was already filled with comments.

(I don't understand, why don't any of you consider traveling to the future?)

(I don't understand either, why didn't they take the principal with them when they time-traveled, and hang out with him!)

(Following the principal, you'll go hungry nine times in three days, but you'll get all the food you need with the hand order. Goodbye, Gongdelin.)

(Haha, but seriously, the principal's method is only suitable for small workshops producing high-quality salt. If you really want to produce it on a large scale, you still have to rely on the saturation method.)

(The best method before the industrial age was to continuously rinse the crude salt with a saturated salt solution. The more times the salt was rinsed, the purer the salt would be.)

"Saturation method?"

Under the sky, everyone was stunned.

They have verified that the soy milk method and the wood ash method are indeed feasible.

However, the problem is that the cost is too high, and large-scale promotion will inevitably put considerable pressure on public finances.

Just as they were racking their brains to find a way to reduce costs, Sky Curtain unexpectedly provided a new answer!