When it comes to preparing gunpowder, we have to mention the huge percentage of saltpeter.
Saltpeter often contains sodium nitrate and potassium nitrate at the same time. Both have the property of absorbing heat when dissolved in water, and can even cause water to freeze. Therefore, saltpeter was also used as a refrigerant in ancient times.
Of course, compared to refrigeration, in Yuan Xi's opinion, what can make saltpeter play a greater role is obviously heating, which is the art of explosion.
But making gunpowder requires potassium nitrate, not sodium nitrate, because the latter easily absorbs water, making the gunpowder damp, seriously affecting the explosion effect, and even causing misfires. Therefore, products mixed with multiple nitrates can only be used as fireworks most of the time.
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But to purify it, it involves two methods of making gunpowder saltpeter. One is to turn sodium nitrate into potassium nitrate through a chemical reaction, and the other is to filter out potassium nitrate from the mixture of sodium nitrate and potassium nitrate, thereby purifying nitric acid.
Potassium.
The simplest and most direct source of nitrate is nitrate soil.
Nitrate is generally soluble in water, so it is difficult to find it in areas with abundant rainfall in summer and autumn. However, in the cold and dry northern areas after spring and autumn, due to sudden changes in temperature, nitrate will crystallize and precipitate, commonly known as alkali ions.
The places where these things appear are often toilets. This is because the urine excreted by humans and animals is rich in urea, which slowly reacts with water to decompose into ammonia and carbon dioxide. Under the action of ammonia-oxygenating bacteria and nitrate bacteria, after a series of
The chemical reaction generates nitrous acid, nitric acid, and finally sodium and potassium plasma in the surrounding environment to generate nitrate. This process is called panuria cocoon in folk proverbs.
In medieval Europe, due to the lack of sources of saltpeter mines, latrine saltpeter almost became the only way to prepare gunpowder. Therefore, urine at that time was listed as a war preparation resource by the royal families of various countries.
And because it is easiest to collect crowds in gathering places, King Charles I of England once issued regulations that asked monks to encourage people to urinate on church benches when they came to church services.
Because people could not leave the pews during worship, a large amount of saltpeter could be collected through this method. Since then, church pews have become an important source of arms for Britain's external expansion.
After obtaining the nitrate soil, it must be purified. If there are too many impurities, even the best gunpowder ratio cannot achieve the effect. This is Yuan Xi's biggest headache.
In the history of China, the ratio of gunpowder has been constantly changing. Although there are reasons for improvement in use, the impurities in saltpeter are also an important factor restricting its development.
The process of purifying nitrate is called boiling alkali and boiling nitrate. In this process, the Chinese people discovered another key raw material.
plant ash.
Its main component is potassium carbonate, which is used to provide potassium ions. By continuously adding plant ash, then dissolving water, heating, and finally filtering, the calcium, magnesium ions and carbonate in the aqueous solution can be effectively removed, leaving only potassium carbonate and carbonic acid.
sodium.
After a series of steps, the purity of potassium nitrate can be improved, thereby assisting the gunpowder to reach the final ratio.
The reason why gunpowder is said to be one of the four great inventions is because it contains a lot of experience and wisdom of the Chinese people. It is really not easy to achieve this step without the assistance of basic chemical knowledge.
The collection of nitrate soil cannot be mass-produced, but the potassium-rich brine in the Montenegro Salt Lake is available in large quantities, and boiling nitrate can not only produce coarse salt and pure nitrate, but also produce brine, which can not only be used
Making tofu can also increase land fertility, killing three birds with one stone.
Therefore, the significance of capturing Montenegro to Yuan Xi is far greater than people of this era thought, but people may not realize this for a long time.
He looked at the last few bamboo tubes on the table, reached for them and put them on his waist. Seeing that Lu Lingqi also wanted to take them, he said, "This thing is very dangerous, are you sure?"
Lu Lingqi said disdainfully: "Isn't it the fireworks that Master set off back then?"
Yuan Xidao: "Although it has not been tested several times, the power this time may be much greater."
"Really?" Lu Lingqi was eager to give it a try, "Click and see!"
Yuan Xi had no choice but to say, "This thing is not easy to handle. It is used to break the formations of armored soldiers and cavalry."
He explained in detail how to use it, saying: "You must throw it out within ten breaths after lighting it, otherwise your hand will be injured. If it explodes in your own formation, it will be a disservice."
After hearing this, Lu Lingqi waved her hands and said, "I understand, don't worry." After saying that, she stuffed the two bamboo tubes into her waist.
Seeing her nonchalant look, Yuan Xi thought to herself that now she was even more worried.
The two of them walked out of the camp side by side and found that everyone was already in formation and ready to go.
The number of people was much greater than what he brought. This was a temporary breakup of the team and mixed in with the reserve armies from several cities around Haixi. Because this time, facing the situation of a large army pressing down on the border, a few thousand people were too few.
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But with new recruits mixed in, in the worst case scenario, the combat power will decrease instead of increase. Then it will depend on how well you perform in battle!
Yuan Xi took a deep breath, raised his hands high, and said, "Break camp!"
One day later, more than 200 miles east of Haixi, Yuan Xijun encountered tens of thousands of Xuzhou refugees.
Following closely behind him were Cao's army's vanguard cavalry disguised as Taishan thieves.
The moment the two armies encountered each other, no one on either side hesitated. They immediately mounted their horses to speed up and charged forward against each other!
At this time, both parties no longer hide their concerns, both know the other's purpose, and there is only one choice at the moment.
Life and death!
The two sides first opened their bows and fired several rounds, then rushed from hundreds of steps to dozens of steps.
The leader, Cao Chun, instinctively felt that something was wrong. Although this was his first time fighting with Youzhou soldiers, he had fought many battles with Lu Bu in Yanzhou with his cavalry before. It can be said that he was familiar with the cavalry.
However, after several rounds of shootings between the two sides, Cao Chun keenly discovered that the opponent's body was extremely stable when shooting, and his shooting speed was faster, so he was more accurate!
He judged from the number of fallen soldiers on both sides that his own side was at a disadvantage once they met!
Seeing that there were still dozens of steps left, the two sides were about to collide. At this time, the soldiers on both sides had already retracted their bows, pulled out their swords from their waists, and were ready to fight at the next moment!
Cao Chun looked at the opponent's armor, which was obviously much more sophisticated than his own, and had a bad premonition in his heart. The opponent's posture seemed a bit inconsistent no matter how you looked at it!
His body was shaken. When the two sides fought, they both held weapons in one hand and blocked the saddle under them with the other hand, but the other party held knives in both hands??
He yelled: "Change!"
After hearing this, Cao Jun's cavalry in front quickly turned their horses' heads in order to avoid the frontal assault of Youzhou Army, but it was already a little too late!
The dozens of riders in front avoided it, but the hundreds of riders behind could not hold back their momentum, thinking that they would bump into each other.
They were also brave, they roared loudly one after another, shook their arms, and slashed out with their swords!
This is the most effective way to kill the enemy immediately with the ring-shou sword. Using the whip-like posture of the arm can greatly increase the force of the slash. Coupled with the sprint speed of the horse, if it hits the opponent's body, even if it cannot break the armor,
It can also cause serious internal injuries to the opponent!
A dense, tooth-wrenching sound was heard, the sound of weapons and armor clashing together, accompanied by screams and muffled hums, resounding throughout the battlefield.
People on both sides kept falling off their horses, but Cao Chun was surprised to find that not only did Cao's army fall much more than the opponent's, but almost all of them became unresponsive after falling, while the opponent could still get up!
He made a prompt decision and shouted: "Turn around and disperse!"
Cao Jun's cavalry immediately distanced themselves, fired two rounds of arrows, and then gathered together thinking of the way forward. Finally, under the leadership of Cao Chun, they retreated on horseback.
After Yuan Xi received news of the conflict between the two sides, he learned that this was the first battle. There were hundreds of cavalry on both sides, and his own side suffered more than a dozen casualties. Cao's army suffered more than half casualties, but he was not happy at all.
Horses and stirrups are used here, and the weapons and armor are also the best. In a head-to-head encounter, it's nothing more than that.
Although he knew that Cao Jun must be more distressed than himself, it seemed that the number of cavalry on both sides could not determine the final outcome of the battlefield. The main force in the decisive battle between the two sides was still the infantry.
And Yuan Xi has learned that Cao Cao has almost transferred all of his most powerful Qingzhou Army to Xuzhou!
Although the Qingzhou soldiers are equipped with average equipment, they are former Yellow Turban bandits and have rich combat experience, so they are extremely difficult to deal with on the battlefield, as you can tell just by looking at Lu Bu's defeat several times.
At that time, Lu Bu had eight capable generals including Zhang Liao, Gao Shun, etc. under his command, and they were defeated several times in battles with Cao Cao. On the one hand, this shows that Cao Cao's tactics were appropriate, and on the other hand, it also shows that the combat power of the Qingzhou soldiers should not be underestimated.
Now that the opponent has an overwhelming advantage in numbers, if Yuan Xi does not have a solution to break the situation, he is likely to be surrounded and killed by the opponent.
Yuan Xi learned another bad news from the refugees in Xuzhou.
When Liu Bei broke up the rear, Cao's army was attacked during a surprise attack that night. The entire army was routed and their whereabouts were unknown.
Yuan Xi's heart tightened, maybe Liu Bei was dead?
Although he understood that if Liu Bei died, it might not be a bad thing for him. Maybe Guan Yu and Zhang Fei came to him for revenge?
However, in later generations Liu Bei was defeated by Cao Cao and disappeared, and Guan Yu surrendered to Cao Cao after being captured. Who can say clearly what happened in this world?
He said to Lu Xun: "Let the soldiers dig trenches and build fortifications on the spot."
After hearing this, Lu Xun hurriedly went out to make arrangements. Soon, the soldiers began to cut trees and dig on the spot, and set up barriers such as horses.
When facing an enemy that is several times larger than one's own, there are two ways to respond. One is to use mobility to eat away at the opponent's weak military strength, and the other is to establish a stronghold for defense.
Originally, according to Yuan Xi's situation, it would be more flexible to adopt the former, but he had to buy time for the fleeing Xuzhou people, so he could only build a defensive offensive in a hurry to prepare for the attack of Cao Cao's main force in an hour or two at most.
As Yuan Xi expected, as the people continued to flee to the rear, Cao's army in the telescope also continued to gather, and it seemed that they were preparing to march in formation.
On Yuan Xi's side, there were only a few thousand soldiers and a simple camp with only a hundred trees.
When Yuan Xi was preparing for the local attack, a spy came with news that Liu Bei's family members were more than ten miles south and were surrounded by Cao's army.
After Lu Xun heard this, he immediately said to Yuan Xi: "You must not act rashly. This is a trap."