In the north of Xiyang City, on the bank of the Santai River, in a large workshop, the drum driven by water is rotating, and there is a sound of "bang, bang, bang" in the drum, and it seems that many hard objects are constantly colliding in the drum.

The clock on the side, the hands pointed to four o'clock, and at this time the sun was in the west, it was four o'clock in the afternoon, a craftsman pulled down the wooden rod next to the drum, and the drum gradually stopped rotating.

The craftsman slowly rotated the drum, let the lid open the lid downward, then use the key to unlock it, open the lid, only to hear a loud rattling sound, a large number of metal discs rolled out of the bottom of the drum, and landed on the wooden groove below.

Wheels were attached to the bottom of the trough, and the craftsman pushed the trough out of the courtyard and went under another yard pergola, where several people were ready.

Wearing cloth gloves, they picked up the hot metal discs from the wooden trough, looked at them carefully, and put them on the bamboo baskets in front of them. Then he took up a pen and began to write in the notebook.

While busy, two people walked into the yard and came to the pergola, one of them was a young man, sturdy and wearing "work clothes", and his voice was full of confidence, and he was the steward of the workshop.

The other person was dressed in a Taoist robe, he looked to be in his forties, his hair was a little gray, and his back was a little bent, but his complexion was very good, and he was also full of confidence when he spoke.

They came to the trough, put on their gloves, and each picked up a metal disc from the trough and examined it carefully.

These metal discs, known as "experimental coins," are similar in size and thickness to those of copper coins in circulation, but they are solid and yellow-white: like a white ring with a yellow disc inlaid in it.

Yellow metals such as gold, white metals such as silver, look like gold and silver inlays, and the production process of this yellow and white two-color coin is developed through the traditional process of "gold and silver mistakes".

Gold and silver mistakes, it is said that there was a craft in the pre-Qin period, this process can decorate gold and silver on bronze, so it is called gold and silver wrong or wrong gold and silver, and slowly evolved into metal decoration techniques, which have been passed down to this day.

These two-color experimental coins have patterns on them, and they are also printed with the words "Yi Mo", Lin Youdi carefully looked at the metal piece in his hand, and found that the pattern on it was seriously worn, and the word "Yi Mo" could barely be seen clearly.

However, the yellow core and the white ring are firmly inlaid, and according to the inspectors' statistics, none of the 300 experimental coins have a yellow core falling off, because this is not a simple brass core embedded in the white copper ring.

Lin Youdi saw the success of the wear-resistant test, and couldn't help but be overjoyed: "Master Liu, thanks to Guanli figuring out the method of adjusting the hardness of brass and white copper, otherwise this two-color coin really can't be made with gold and silver wrong technology." ”

Liu Yang looked at the two-color experimental coin in his hand and nodded quite smugly: "That's, that's, it took years to figure it out, it's not easy..."

"It's just that the wear resistance is still a little worse, although the brass and white copper have not been separated, but the patterns printed on them are too worn, if the coins are minted in circulation in this way, I am afraid that after a few years, the patterns on these two-color coins will be worn beyond recognition."

In the face of Lin Youdi's sigh, Liu Yang was not so pessimistic, he and his apprentices and Taoist friends, with the help of the beamsplitter, discovered the magical world, and discovered many secrets of "metal elements", whether it is white copper or brass, only need to test the formula repeatedly, and you will definitely be able to try out the best alloy ratio.

Liu Yang, who has been in Xiyang for six years, now looks much better than back then, although the years have left a mark on his face, but Liu Yang, who has practiced the "way of chemistry" slightly, has been reborn.

The Wuzhuang Temple, which was established with the strong support of King Xiyang, created an excellent "experimental environment" for Liu Yang and his colleagues, where they could devote themselves to the study of "the way of chemistry", and the results were remarkable after so many years.

Among them are the perfection and application of "alchemy" and "silver".

Alchemy is an alchemy technique that Liu Yang pondered by himself, using copper as gold, and earning a meager income from the scattered gold to support his alchemy career.

It wasn't until he met Yu Wenwen that he knew that he had gone astray, and what came out of alchemy was not gold, but copper-zinc alloy, called "brass".

And the "chemistry" door opened by Yuwenwen for Liu Yang allowed him to discover a new world and have the motivation to continue living.

In Wuzhuang Guan, Xiyang, Huangzhou, Liu Yang attracted fellow alchemists from all over the world with the help of a magical spectroscope, exchanged a lot of experience with each other, and also collected a large number of Dan prescriptions, including "silver pointing".

The so-called silver pointing, also known as atractylodes, is to use realgar or arsenic to turn the copper produced in Danyang into silver, and in the view of Liu Yang, who has studied chemistry, this is the "chemical reaction" between arsenic and copper alloy, making it turn into white copper, which looks white and shiny, but is not actually silver.

This kind of white copper, Liu Yang named arsenic white copper, and also found that arsenic white copper will turn brown after a long time, which should be because of the volatilization of arsenic elements in the alloy, and it is precisely because of this that arsenic white copper is toxic.

When a large amount of arsenic white copper is melted, the arsenic-containing gas produced will poison small animals, so it is necessary to be very careful when using it.

Arsenic white copper is not safe, and the Taoist priests of Wuzhuang Temple have discovered another kind of white copper in their experiments day after day, that is, adding a certain amount of lead to bronze (copper-tin alloy), and then adjusting the content of tin, will make the new copper alloy appear white, like silver.

Such white copper is not as toxic as arsenic white copper.

With brass (so-called gold) and white copper (so-called silver), these two copper alloys were inlaid together in a process similar to gold and silver to make a two-color currency of gold and silver (yellow and white).

In this way, the difficulty of making counterfeit money will inevitably increase significantly, and no one can even imitate it, this is the idea of King Xiyang, a few simple words, Liu Yang took several years to barely realize.

The gold and silver two-color coins produced barely passed the wear-resistant test today, and the experimental coins collided with each other in the drum for three consecutive days, although they were pitted, but the gold (brass inner core) and silver (the copper outer ring) were not separated.

This means that the gold and silver error process jointly researched by Wuzhuang Guan and the workshop has surpassed the traditional gold and silver error process, and the blue is better than the blue.

Then the next goal is to make the patterns and words on this two-color coin more wearable, but when the expected goal can be achieved, no one can say for sure, this may take several years to achieve, but Xiyang Wang can afford to wait.

The pattern of the two-color coin, Lin Youdi has already let Sima Zhang Dingfa, who rushed to the main account of Lang to listen to the order, take it away, and now, he looked at the two-color coin in his hand in a daze, and Liu Yang beside him was also the same.

Liu Yang is now thinking about technical issues, while Lin Youdi is thinking about cost issues, because cost issues are the key to determining whether two-color coins have practical value.

Lin Youdi knew that the cost of making (minting) a two-color coin would exceed 500 Wen, and it would definitely drop to less than 500 Wen in the future, but Lang Lord Yuwenwen's requirement for two-color coins was that the face value should not be greater than 100 Wen.

That is to say, we must find ways to improve the process, so that the cost of minting coins to less than 100 Wen, only in this way, the two-color coin has the possibility of practical use, otherwise it is really used to mint coins, the more minted, the more losses.

This requirement is too harsh, Lin Youdi really can't understand why Lord Lang doesn't set the value of this two-color coin at 500 Wen or 1,000 Wen (consistent), so that the cost problem is not a problem, and he can even make money by minting coins.

As the manager of the workshop, he actually doesn't need to worry too much about this matter, and there is a special "technical research team" to re-improve the new gold and silver error process to reduce costs.

The practical application of the production process of the two-color coin, the deadline given by the Lang lord is very lenient, almost nothing, probably not to give up too much hope for this, but Lin Youdi will not give up so easily, what the Lang lord tells him to do, whether it can be completed in the end, he will do his best to do it.

Looking at the two-color coin in his hand, Lin Youdi thought again: Liu Guan used the way of chemistry to make brass and white copper, so can he use the way of physics to greatly reduce the production cost of the two-color coin?