Wang Wei held on to the watchtower to command the defensive battle, and when Wang Mo told him that the Bearded Man had retreated, he was already dizzy and could not support his body.

"Captain... Captain... ”

Wang Mao's eager call became more and more distant.

Wang Rong's eyes were already dark, and he fell into a long and complicated dream.

In the dream, he is no longer a bloody captain, but a student sitting in the classroom.

In front of the podium, the history professor plays a slide show about gunpowder, one of China's four great inventions.

The professor's voice rang in his ears: "You all know that gunpowder, as one of the four great inventions of China, is of great significance to China and even the world.

Gunpowder, as the name suggests, refers to an agent that can cause violent combustion by fire. As early as the Spring and Autumn Period, Fan Li's "Fan Zi Jiran" has a record of 'saltpeter out of Longdao'. ”

The slide page flips, and the screen shifts from a clump of old bamboo slips to an open thread-bound book.

"During the Sui Dynasty, the ancients discovered that saltpeter, sulfur and charcoal were mixed together and burned violently. Black gunpowder officially appeared in the Tang Dynasty. And we now see that it is the first book in China to record the formula of gunpowder, which was written in the eighth and ninth centuries, that is, during the Tang Dynasty and the Five Dynasties. It is recorded in the book that 'sulfur and realgar saltpeter are combined with honey and burned', and that 'flames rise, and the hands are burned and the houses are burned out'. The 'honey' here is honey. Honey is heated into carbon, mixed with sulfur and saltpeter, and this is the recipe for gunpowder.

From this recipe, we can see that the origin of gunpowder is alchemy. Alchemy appeared very early, during the Warring States period, there were monks who offered the medicine of immortality to King Jing, and in the Han Dynasty, Emperor Wu of the Han Dynasty had the delusion of 'longevity and long-term vision', and alchemy began to prevail. Alchemy practitioners have appeared in all dynasties, and there is a very important method of alchemy they use called 'fire alchemy'.

'Fire alchemy' is a waterless heating method, the famous alchemy master Ge Hong of the Jin Dynasty has the following record of fire alchemy in "Hug Puzi": calcining, long-term high temperature heating; refining, heating of dry substances; moxibustion, local baking; Melting, that is, melting; Pumping, which is now called distillation; Flying, also called ascending, is sublimation; Excellent, that is, heating denatures the substance.

These methods are the most basic chemical methods until now, but at the time they were the basis for alchemy to produce inventions.

The persistence of the alchemists in finding the elixir of immortality made them more and more courageous. Through constant trial and error and the search for new methods, the conditions for the invention of gunpowder were created. ”

At this point, the professor changed another slide, and there were sulfur, arsenic, and other items in the picture, and he continued: "In ancient alchemy, the most used raw materials were sulfur and arsenic, but these things are all highly toxic gold and stone medicines, how can the toxicity be reduced or lost? The face squarers came up with a solution, 'ambushing the fire'. In the early years of the Tang Dynasty, Sun Simiao, the "King of Medicine", was also an alchemy alchemist, and he recorded in the "Danjing Inner Sulfur Law": sulfur and saltpeter are two taels each, ground into powder, and placed in a silver pot or sand jar. Dig a pit and place a pot or jar in the pit to be level with the ground. Fill all sides with earth. Use three soap horns that have not been eaten by insects, point them one by one, and then put them in a pot to set the sulfur and saltpeter into fireworks. When the fireworks can't be burned, then take the charcoal to fry, fry until the charcoal is gone, then anneal, while it has not cooled, take out the mixture, and this will ambush the fire.

Similarly, in the middle of the Tang Dynasty, there was an alchemy alchemist named Qing Xuzi, who made improvements to the method of ambushing fire in his "Fuhuo Alum Method": the method was similar to the above, except that the soaphorn was replaced by three and a half coins of aristolochia.

No matter what kind of fire method is used, there is the existence of carbon, and sulfur should be added to saltpeter, and saltpeter should also be added to sulfur. Thus it is known that the ignition of sulfur, nitrate, and carbon will react violently, and the three substances can constitute an extremely flammable medicine, which is called gunpowder.

Gunpowder, on the other hand, was used as medicine before it entered military use. In the "Compendium of Materia Medica", it is mentioned that gunpowder can cure sores and ringworms, kill insects, and dispel dampness and plague.

But gunpowder is not immortal, and it is unstable and easy to catch fire, so alchemists are not interested in it. Gunpowder was thus used for military purposes, and during the Tang Dynasty, gunpowder began to be used for military purposes, and the earliest record appeared in Lu Zhen's "Chronicles of the Nine Kingdoms" in the Song Dynasty. ”

Then the professor moved the slide to the next one, in this film, there are a lot of relatively old gunpowder weapons, the professor pointed to the first picture with a wooden pole and said: "In the Song Dynasty, gunpowder weapons developed rapidly, "Song History: Soldiers" recorded: Kaibao three years, the military department ordered Shi Feng Ji to ascend to the gunpowder arrow, this method is to tie the gunpowder cartridge at the front end of the arrow shaft, and use the reaction force of gunpowder combustion to spew gas backwards after ignition to shoot the arrow cluster, which can be said to be the world's earliest jet firearm.

In the third year of Xianping, Tang Fujin, the captain of the Divine Guard, who was born in the army, presented his self-made rockets, fireballs, firetops and other firearms. In the fifth year of Xianping, Shi Pu also made rockets, fireballs and other firearms and performed them.

The appearance of gunpowder weapons on the battlefield indicates that a series of changes will take place in the mode of warfare, and cold weapons will transition to firearms.

The original form of gunpowder weapons was mainly based on the incendiary properties of gunpowder. The early gunpowder weapons recorded in the "General Essentials of the Martial Arts" did not deviate from the category of arson weapons in traditional fire attacks. And with the development of gunpowder and gunpowder weapons, it gradually went over to the advantage of its explosive properties.

Gunpowder made by mixing potassium nitrate, sulfur, and charcoal powder is called black gunpowder. This mixture is extremely flammable and burns quite violently. An explosion occurs if the gunpowder burns in a closed container.

During the Song Dynasty, the firearms commonly used on the battlefield were tribulus fireballs and poison smoke balls. The more powerful ones are thunderbolts and earth-shattering thunderbolts.

In the fourth year of Qingli, Zeng Gongliang's "Wujing General Essentials" recorded three gunpowder formulas, with different auxiliary materials, to achieve different purposes of flammability, explosiveness, poisoning and making smoke screens.

The war promoted the development of gunpowder and gunpowder weapons. During the Southern Song Dynasty, tubular firearms appeared, and in the second year of Shaoxing, Chen Gui invented the musket. This musket is made of a long bamboo pole, which is first loaded with gunpowder and then ignited and sprayed at the enemy during the battle.

In the first year of Kaiqing, the craftsmen of Shouchun made assault rifles. The assault rifle, also known as the assault torch, is made of a thick bamboo tube. This tubular firearm differs from the musket in that it can only shoot flames to burn people, while the assault rifle is equipped with a 'sub-nest', and when the gunpowder is ignited, a strong gas pressure is generated to shoot the 'sub-nest'. The "sub-nest" is the primitive bullet. The assault rifle pioneered the projectile fired by a tubular firearm.

By the time of the Yuan and Ming dynasties, this primitive tubular firearm made of bamboo tubes was cast with copper or iron, and was called 'fire gun'. The three-year copper firearm made in the Yuan Dynasty to Shun is the earliest existing tubular firearm with inscription in the world.

By the time of the Ming Dynasty, there was a new development in combat firearms. For example, there are 'multi-launch rockets' such as 'Fire Ballista Meteor Arrow' which can fire 10 arrows at the same time, 'Swarm of Bees' which can fire up to 30 arrows, and 'Hundred Tigers Running Arrow' which can fire up to 100 arrows. This is the world's first multiple salvo rocket, which can be called the ancestor of modern multiple rocket launchers.

Among them, it is worth mentioning a firearm called "fire dragon out of the water", which was used in water warfare at that time. According to the records of the "Wubei Zhi", this firearm can fly at a height of three or four feet above the water, as far as two or three miles. The main body is made of bamboo and wood, and four large 'fires' are tied to the shell, and several small rockets are hidden in the belly of the rocket, and the large 'fires' are ignited to propel the rocket body to fly, 'like a fire dragon out of the water'. When the gunpowder is burned out, it ignites a small rocket in the abdomen and shoots it out of the mouth. Hitting the target will burn the enemy. It can be said that this is the world's first second-stage rocket.

There is also a firearm called 'Shenhuo Flying Crow', which is made of fine bamboo tissue paper and pasted into a crow-shaped, filled with gunpowder, propelled by four rockets, it is the world's earliest multi-powder cartridge parallel rocket, and it is very similar to the working principle of today's large bundled launch vehicles. ”

While listening to the professor's narration, Wang Rong silently recorded this knowledge in his mind, and just as the professor talked about the formula of gunpowder, the picture began to shatter, and the sound became ethereal.

"Captain! Captain! ”

Wang Wei heard it, this was Wang Hao's voice. Wang Rong struggled to open his eyes, and the illusory dream was completely gone.

The canopy of the Chinese army's tent appeared in Wang Wei's field of vision, and then Wang Mao's anxious face, while Zhang Pu, who was sitting on the edge of the bed, was treating himself.

"Wake up! The Captain is awake! ”

"Great! That's great! ”

It was only Wang Rong who discovered that there were not only Wang Mao and Zhang Pu in the tent, but also Han Qian, Ma Yuansi, Zhou Yi, Zheng Zijin, and Li Sujie.