On this morning, a large caravan appeared on the official road outside Zhangye City, this caravan consisted of more than 1,300 camels, the camels were loaded with boxes and sacks, nearly 100 men rode on horses, and there were 2,000 cavalry guards, the owner of this caravan was Zhang Lei.

Zhang Lei trekked from Chang'an, and their ships waited in Tianshui for two days, and the Lang general Zhang Cheng led 2,000 cavalry and more than 1,000 camels to arrive.

There are a total of 100 large boxes, but after the outer boxes are removed, they become 400 medium-sized boxes, and 200 camels are enough, but there are still 20,000 catties of saltpeter mines in Tianshui's warehouse, which must also be transported back to Hexi.

Escorted by 2,000 cavalry, the journey was very smooth, and finally arrived at Zhangye City.

"Proprietor Zhang, we're here!" Yang Jun shouted.

Zhang Lei's heart hanging high in the air suddenly relaxed, although this way under the deliberate care of the Dugu family, they came over without danger, but Zhang Lei was still very nervous, especially in the way out of Chang'an and out of the customs, for fear of being discovered and detained by the Hidden Sword Pavilion.

Fortunately, they often transported wine, rented several large warehouses in Tianshui in advance, and more than 100 personal soldiers were responsible for carrying the whole process, and spent 1,000 taels of silver to buy off the captain on duty of the Fengxiang Army at the Weihe Pass, and with the help of night cover, they finally left Guanzhong by water.

Zhang Lei grinned, turned around and said, "Everyone has worked hard in the past few months, and I will invite everyone to drink when I go back." ”

Guo Song's personal soldiers were already familiar with him, and one of his personal soldiers asked loudly: "Zhang Dongzhu, does Zhang Ye have Meishou wine?" ”

"Yes! I have hid some jars in the place of your envoys, and when the time comes, I will steal them out and give you to drink. ”

The soldiers laughed loudly, and the camel team did not enter the city, but directly entered the camp outside the eastern city, where Guo Song had been waiting for a long time.

The soldiers dismounted one after another, knelt down on one knee to salute, and Zhang Lei hurriedly said: "Thanks to them this time, without them, I wouldn't have been able to transport it this time." ”

Guo Song smiled and nodded, "Everyone will work hard in the end, move the wooden box into the side tent, and then eat and sleep." ”

The soldiers received the order to take the two hundred camels to the side tent, Guo Song asked Zhang Lei with a smile: "Didn't you say that you will only set off at the end of February?" How did you leave a month earlier? ”

"Don't mention it!"

Zhang Lei said hatefully: "I was almost discovered by Li Man's slut, but fortunately, the fat master and I were clever and quick to react, and I fled from Chang'an that night, otherwise you and I will have worked hard for half a lifetime, and this time next year will be my anniversary sacrifice." ”

"It seems that I still owe a lot of favors to the Dugu family this time?"

Zhang Lei nodded, "They have been sending us out of the pass, a total of four levels, especially in Tianshui, we waited for two whole days, the army came to check several times, if it wasn't for them to greet the local garrison, we would really be finished, originally I also planned to use money to buy through the various levels, only to find out later that in addition to the Fengxiang level, other levels do not eat this set at all, but I heard that it is the fleet of the Dugu family, so I didn't check it at all, and let it go directly." ”

"Let's give back when we have a chance in the future!"

The two entered the big tent, Guo Song asked Zhang Lei to sit down and rest, let people serve tea, Guo Song said to Zhang Lei: "You don't want to go back for the time being, the current situation is very chaotic, three days ago, Longyou Jiedu made Zhang Yi assassinated by a concubine next to him, and the concubine actually escaped, this assassination style reminds me of the Tibetan Sword Pavilion, and the prison army Tian Wenxiu impeached me for rebellion, I thought that the Son of Heaven was going to send someone to arrest me and return to Beijing, but in the end there was no movement." ”

Zhang Lei said for a while: "It is estimated that the emperor is afraid of forcing you to rebel!" If anyone dares to arrest me, I just don't want to rebel and rebel. ”

Guo Song smiled slightly: "You are right, I guess I am afraid of this, so the Son of Heaven held back." ”

Zhang Lei hesitated for a moment and asked in a low voice: "You transferred your wealth to Ganzhou, do you really plan to rebel?" ”

Guo Song shook his head, "I can tell you frankly, unless I am cornered, I will never rebel, I promised the master back then, to protect the Tang Dynasty, if I rebel, I am sorry for the master's spirit in the sky." ”

Speaking of promises to Master, Zhang Lei was also silent, he had made many promises to Master back then, but none of them were fulfilled, how should he face Master's spirit in heaven? ”

Guo Song patted him on the shoulder, "Go and rest!" We'll talk about it when we have time. ”

.........

There is a Taoist temple in the south of Zhangye City, called Laojun Temple, the Taoist Temple is not big, covers an area of only five acres, but it has long been empty, abandoned for more than ten years, last winter, the government bought this Taoist temple, it was renovated, a few days ago ushered in a new group of Taoist priests, from the Kongtong Mountain Yunxiao Heavenly Palace of the Beifeng Zhenren, and his ten apprentices.

Beifeng Zhenren is an old Taoist priest of alchemy, obsessed with alchemy, in the decades of alchemy, in order to distinguish between miscanthus nitrate and fire nitrate, he invented the sulfonite method, mixed with sulfur powder and nitrate powder, which can burn violently is fire nitrate, on the contrary, it is miscanthus nitrate, which is actually gunpowder.

In order to purify the nitrate powder from the saltpeter mine, Beifeng Zhenren tried all kinds of methods, and finally used the boiling filtration method, after many times of boiling and filtration, he refined the fire nitrate powder with a high purity, and many alchemy Taoist priests came to learn from him.

It is the alchemy Taoist priests of the Tang Dynasty who continue to promote the sulfonite method, at this time gunpowder has appeared in the lives of ordinary people, and sulfonite powder can be bought in the pharmacy, which is used to treat sores and ringworms, kill insects, dispel moisture, and extinguish the plague, and finally changed the use of the army in the process of extinguishing the plague, and gunpowder appeared on the battlefield in the middle and late Tang Dynasty.

Guo Song walked quickly to Laojunguan, walked into the door, and saw a Taoist priest in his thirties who was struggling to hammer medicine in the stone mortar, his name was Qingxuzi, he was the big apprentice of Beifeng Zhenren, with big shoulders and round waist, but he was very honest and honest, and he had followed the master for more than 20 years, and he had won the true inheritance of the master in alchemy.

"What is Senior Brother Qingxu messing with?" Guo Song stepped forward with a smile.

Qing Xuzi turned around and saw that it was Guo Song, and he was immediately startled, and hurriedly said respectfully: "I dried the aristolochia and pounded them into powder, and I want to try it instead of soaphorn powder." ”

His fear of Guo Song was not entirely because of Guo Song's identity, but when he saw Guo Song burning the Heavenly Temple, he was fortunate to run fast, otherwise he would have been burned to death, their alchemy Taoist priests did not know martial arts, and they were scared enough at that time, and the situation when the Heavenly Temple dozens of feet high fell down is still fresh in my memory.

Guo Song knew that the Beifeng Taoist was old, and he basically didn't do it himself, and the purification of nitrate powder was done by the apprentices, and this Qingxuzi was the best among them, with rich experience, and the best nitrate powder was purified by him, even surpassing the master.

Guo Song looked at the powder in the stone mortar, and asked with a smile, "How did you think of using aristolochia?" ”

Qingxuzi scratched his head and said: "Originally, I used soap horn powder, but I feel that soap horn powder is not enough to detoxify, aristolochia detoxification effect is quite good, I plan to use sulfur two taels, nitrate two taels, aristolochia three and a half dollars, and then go to the alum fire, the toxicity of lead pill will not be so heavy." ”

Only then did Guo Song remember that the purpose of their gunpowder refining was to remove the poison of arsenic, which was completely different from what he wanted.

"Where's your master?"

"Master is taking a nap, I'll call him."

Guo Song hurriedly stopped him, "You don't need to wake up your master, I'll tell you, the saltpeter has arrived, and you can start refining nitrate." ”

Guo Song spent a lot of money to invite them, just to learn their alchemy skills, and he specially arranged a group of henchmen and soldiers.

Qingxuzi nodded, "Master has already told me, as long as saltpeter is delivered, I and my two junior brothers will go to the military camp to teach nitrate refining, or do you want to go now?" ”

"Don't be in such a hurry, you prepare today, and then you come to the barracks early tomorrow morning, I have prepared the nitrate refining list you opened last time, you see what is missing?"

"I'll take a look tomorrow, there should be no shortage of them."

"Then I will arrange for my own soldiers to pick you up early tomorrow morning."

.........