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 and makes the gunpowder damp, which seriously affects the explosion effect and even misfires. Therefore, products mixed with multiple nitrates can only be used as fireworks in most cases. .
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 successively generates nitrous acid, nitric acid, and finally sodium and potassium plasma in the surrounding environment 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 included in the war preparation resources of royal families of various countries.
And because crowd gathering places are the easiest to collect, 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 cannot leave the pews during worship, a large amount of saltpeter can be collected through this move. 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 will not be able to achieve the effect. This is Yuan Xi's biggest headache.
In Chinese history, 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 with it 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 what 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 Xi said: "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 armor soldiers and cavalry formations."
He explained in detail how to use it and said: "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 two bamboo tubes into her waist.
Seeing her nonchalant look, Yuan Xi thought to herself that now she was even more worried.
The two 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 larger than what he brought. This was a temporary breakup of the team, mixed 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. .
But with new recruits mixed in, in the worst case scenario, the combat strength will decrease instead of increase. Then it will depend on how well they perform in battle!
Yuan Xi took a deep breath, raised his hands high, "Bring out 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 Jun'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 sides no longer hide their concerns, they 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, rushing 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 shooting 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 feeling in his heart. The opponent's posture seemed a bit inconsistent no matter how you looked at it!
His body was shaken. The two sides were fighting. They were both holding weapons in one hand and blocking the saddle under them with the other hand. But the other party was holding knives in both hands? ?
He yelled: "Change!"
After hearing this, the cavalry of the Cao Army in front quickly turned their horses' heads in the direction of the Youzhou Army, trying to avoid the frontal assault by the 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, 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 other party!
There were dense, tooth-wrenching sounds, the sound of weapons and armor clashing together, accompanied by screams and muffled groans, resounding across 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 have 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 such as Zhang Liao and Gao Shun 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. On the other hand, it also shows that the combat power of the Qingzhou soldiers should not be underestimated.
But now that the opponent has an overwhelming numerical advantage, if Yuan Xi does not have a solution to break the situation, he is likely to be surrounded and killed by the opponent.
From the mouths of the fleeing people in Xuzhou, Yuan Xi learned another bad news.
When Liu Bei broke up the rear, Cao's army collapsed during a surprise attack that night, and their whereabouts are unknown.
Yuan Xi's heart tightened. Is Liu Bei 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 is going on 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 faced with 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 expected by Yuan Xi, 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 a 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."
(End of chapter)
