After talking to Guo Zi for a while, Xu Ping saw that it was still early, and stood up and said, "Let's go with me to the place where drums are cast, I'll show you something. ∈◆There is one thing that I've been waiting for you to take office, and the others are worried about doing it."

Seeing that although Xu Ping was his boss, he still treated himself as he was back then and was not unfamiliar with him, Guo Zi felt at ease. Along the way, he was also worried that Xu Ping would become powerful when he was successful and would become more powerful and become more inflated. If he was arrogant to himself, it would be difficult to get along with in the future.

The two of them left the Sansi Yamen, and in less than a long time, they would arrive at the place where Sansi was minted.

The coin minting prisons of this era were basically located near copper mines. There was no copper mine near Bianliang. This coin minting prison mainly molten old coins to cast new coins. With the increase in the number of other coin minting coins, this coin minting prison has long been abolished and has only been cast in Sanshi sample coins.

Seeing this, Guo Zi asked, "Why, the deputy envoy wants to cast new coins? I heard that Xu Shen wants to cast coins with iron and copper. Didn't he try it without any effect?"

Before coming, it was agreed that Guo Zi would be responsible for the salt, tea and iron-san case, and it was not surprising that Xu Ping brought him here.

Xu Ping smiled, without answering, but just led Guo Zi to the Qianjian.

The public officials on the road saluted Xu Ping when they saw Xu Ping, but Xu Ping did not stop and led Guo Zi to the deepest part of the Qianjian.

There is a row of three separate houses at the deepest part of the Qianjian. A general outside the door was guarding him with two soldiers. When Xu Ping arrived, the three of them hurriedly bowed and bowed.

Xu Ping took out a key and handed it to the military general, asked him to open the door, turned around and said to Guo Zi, "You will know what you will do in the future when you come here to see it." Guo Zi was confused and followed Xu Ping into the room.

At this time, the sun was rising, the windows in the room were not sealed, and the things in the room could be seen clearly under the sun.

There are several large porcelain jars on the shelf next to it, all sealed tightly, and I don’t know what is inside. There are two long grooves in the middle of the room, which are also inlaid with porcelain pieces, but at this time there is nothing inside.

Apart from these, Guo Zi looked around and found nothing special.

Seeing that Guo Zi was not noticed, Xu Ping waved to him: "Follow me!"

When he arrived near the trough, Xu Ping pointed to the black round square holes on the ground and said, "Zhongmou, how are these iron coins cast? Can they still be used?"

Guo Zi then noticed these little things on the ground. He bent down and picked up one, looked left and right, and asked Xu Ping with his head, "Second envoy, is this an iron coin? It's so dark, how can you tell it is iron? During the Chunhua period, Zhao Anyi asked to cast the top ten iron coins in Xichuan, and refining them again and again, it was as bright as silver, but it was not in the eyes of the ministers!"

Xu Ping smiled and said, "Although the money cast by Zhao Anyi looks good, it can be broken when it falls on the ground. How can I use it? Although my iron coins are a bit impressed, they are as hard as gold and stone. If you don't believe it, you will fall on the ground and look at it."

This kind of thing is not a joke, and Guo Zi was not polite and threw the iron coins in his hand to the ground. With a "bang", the black iron coins bounced on the ground a few times and got out of the distance.

Guo Zi quickly stepped forward and picked up the iron coin in his hand. He looked carefully. Not only did he not have a crack, but even the black surface was as intact as before and without any damage.

Guo Zi was curious and wiped the edge of the groove in front of him with the black iron coins in his hand a few times. He picked it up and looked at it. He saw that there were only some debris on the edge of the groove, and his black gas was still unchanged.

Unable to help but feel surprised, Guo Zi said, "Make a mistake! Deputy envoy, if this is an iron coin, what is it applied on the outside? No matter how you fall, you can't even get rid of it?"

"This is where this money is expensive." Xu Ping's face has color. "This black is naturally generated after using medicine. It is not only colored, but also anti-rust and corrosion. Xichuan has used iron coins for many years. One is that the money is light and the goods are heavy, and it is inconvenient to carry. The other is that it is easy to rust and not durable. Although the iron coins I cast are also inevitably light, they have removed the disadvantages of easy rust and can still remain the same after decades of use."

Speaking of this, Xu Ping pointed to the ground and said, "Look, there are ten pieces here that have been soaked in water for more than a month. They still remain the same. Where can ordinary iron coins be like this?"

Only then did Guo Zi notice that the iron coins on the ground were not sprinkled casually, but were intentionally for it. Some were soaked in water, some were in wet places, some were in dry places, and some were even half buried in the soil, simulating various environments.

Guo Zi took out the iron coins one by one and saw that they were as intact as before. He was even more curious and bowed to Xu Ping and asked, "Do you dare to ask the deputy envoy, what secret method is this? Can I know?"

"You are recruiting you to Beijing and you are in charge of the three salt, tea and iron case. How can you hide it from you? However, this secret medicine is quite troublesome to prepare, and I will tell you one by one in the future. There are still some in the jar on the shelves over there, and I don't know if it is broken."

After hearing Xu Ping's words, Guo Zi couldn't help but open the three jars on the shelf. Seeing that the three inside were white powder, they looked almost the same, and I didn't know what the difference was.

Xu Ping saw two disadvantages of copper coins now. One is that they are too heavy and inconvenient to carry. Although the flying money business operated by Sansi has a handling fee of 20 ounces, as long as the distance is a little further, it is actually a loss business. The other is that the value is too high and the small business in the market is very inconvenient.

The most common commercial activity of small farmers and small households is to sell an egg for needles and threads. How many cents will be sold for an egg? What about a needle? What about a small handful of money? In fact, it can only barter with goods, which is quite inconvenient and not conducive to government management.

It is more troublesome to deal with difficult problems. Xu Ping plans to put them later and solve them. He will gradually accumulate political resources. With political capital, there will be less resistance. Now the first step is to solve the problem of miniaturization of currency first.

According to the experience in Sichuan, iron coins will roughly be in the ratio of 5 to 1. Even if the government forcibly raises the price of iron coins, it will slowly depreciate to this reasonable range. In fact, the price ratio of iron coins in Sichuan was first established as one thousand one hundred cigarette iron coins and one thousand cigarette copper coins, which quickly depreciated to 1,500 to 1,000, and then to three to one, four to one, and until now, the 5 to one stable is not changed by people's subjective will.

If iron coins worth one fifth of the copper coins can be used, small-scale trade among the people can be activated, which is the first step.

As for the black that is rust-proof and corrosion-proof on the outside of the iron coins, it is nothing to say. It is the steel "black" treatment in later generations. The steel surface oxidizes the surface to form a dense iron tetroxide film. The chemical properties of iron tetroxide are quite stable and can protect steel from corrosion for a long time. The only difficulty is the preparation of the so-called secret medicine, caustic soda is causticized with soda ash and lime, nitric acid is dried to remove nitric acid, and then react with nitric acid and caustic soda to obtain sodium nitrate, and heat sodium nitrate to obtain sodium nitrate. Xu Ping is very familiar with the "black" process, but it took several years to prepare these blackening agents used.

Xu Ping first wanted to make black agents to prevent rust by the copper cannons cast at that time. Although he had been experimenting in Yongzhou for a long time, he had not succeeded. The main difficulty lies in the preparation of nitric acid. When he returned to the capital to make it, he had a new purpose.
Chapter completed!