Li Yuan didn't eat lunch in the palace. When he heard that he had vegetarian food, he happily agreed and followed Qingyu's footsteps to the side hall of Xingyun Temple, which was a sacrifice to the gods of the heavens.

The vegetarian food is very good, with a bowl of noodles and some cold wild vegetables.

Taoism respects the unity of man and nature, so it has always liked to eat wild vegetables. The upper and lower classes of the Tang Dynasty also had a trend of eating wild vegetables. The Supreme Emperor ate quite a lot in the palace.

However, even a vegetarian dish in the palace is very interesting, while the Taoist temple is much lighter, simple to cook, and it tastes a bit natural.

Li Yuan picked up the bowl and drank the soup from the noodles. After looking at Qingyu, he said, "Master Qingyu, there is no other meaning when he comes here this time. He just asks you for help. Some ingredients are difficult to find in the outside world, but in your Taoist temple... it is easy to find..."

Although movable type printing is faster than woodblock printing, how to make "movable type" is indeed a difficult problem. After Bi Sheng in the Song Dynasty invented movable type printing, he successively used clay movable type and wood movable type printing.

The clay movable type is made of clay into a blank with the same specifications. The reverse single characters are engraved on one end. The protruding height of the letter mark is the same as the thickness of the edge of the copper coin. It is burned hard with fire to become a single clay movable type. In order to meet the needs of typesetting, there are generally several or even dozens of commonly used characters for repetition in the same version. When encountering uncommon characters, if they are not prepared in advance, they can be made as they wish.

To facilitate the selection of characters, place the clay movable characters in the wooden grid according to the rhyme and put them on paper strips to indicate. When typing, use a framed iron plate as the base support, apply a layer of potion made of rosin, wax and paper ash on it, and then select the needed clay movable characters one by one into the frame. After the frame is filled, it becomes a plate, and then bake it with fire. When the potion is slightly melted, use a flat plate to flatten the literal surface. After the potion is cooled and solidified, it becomes a pattern. When printing, just brush in the pattern, cover it with paper, and add a certain pressure. In order to continuously print, use two iron plates, one sheet adds brush, and the other sheet is arranged in type, and the two plates are used alternately. After printing, use the potion with torch and shake it gently with your hands. The movable characters can fall off the iron plate, and then press the rhyme and put it back into the original wooden grid for use next time.

Later, Bi Sheng also tried to print wood movable type, but due to the uneven texture of the wood, the difficulty of carving, the deformation of the wood movable type after being dipped in water, and the difficulty of being easily separated when stuck with the agent, he did not use it.

For the Emperor, what he had to do was not only movable type printing technology, but also the lead movable type printing machine invented by Gutenberg. What the lead movable type printing machine needed was lead movable type, which is commonly known as "copper mold".

The copper mold needs to be mixed and fused in proportion to three metals: lead, antimony and tin.

The content of lead in bronzes from Shang and Yin to Han dynasties tended to increase. The increase in lead in bronze played an important role in improving the fluidity of liquid alloys, revealing the casting patterns.

However, the ancients did not have a clear distinction between lead and tin. The Romans called lead black lead and tin white lead. Alchemists conducted experiments on some compounds of lead and lead, for example, in the "Zhou Yisan Tongqi" written by Wei Boyang, saying: "When Hu powder hits fire, the color is still lead." It is expressed in today's chemical equation: Pb3O4    2C  --→  3Pb   2CO2↑

Lead is essential in the smelting of bronze ware, so it is easy to find, and the same is true for tin. In ancient times, furniture supported by tin could be seen everywhere. In the 1980s and 1990s, a large number of kettles were made of tin.

However, compared with the previous two types, antimony is hard to find. Although China is the world's largest antimony storage country, it contains 89% of antimony minerals.

However, it is still difficult to get pure antimony. According to the "Han Shu Shi Huozhi" record: "Wang Mang's life was taken by the Han system and used copper to mint coins. It was confusing to connect tin."

The Qin Dynasty arrows unearthed in the Qin tomb contained antimony after spectral analysis. From this, we can see that China used antimony very early, but it was not called antimony at that time, but "Lian Tin".

The Supreme Emperor came to Xingyun Temple today not just to eat a bowl of noodles, but also to hold on to you that you can find antimony in Xingyun Temple.

After all...the Taoist priests who refined alchemy have the most various compounds here.

"It turns out that I am looking for materials..." Qingyu breathed a sigh of relief. It was the most difficult to refine pills for these emperors and generals. Accompanying the king is like a tiger, so how could the landlords come easily?

"What kind of elixir do you want to refine? Although I am not capable, I can still rank among the top three in Chang'an..." Qingyu said with a smile.

In his opinion, the Supreme Emperor must have been looking for elixirs to refine elixirs, and he could not think of any other reason.

"I still want to live longer." Li Yuan glanced at Qingyu. Everyone was a Taoist priest, so there was no need to deceive themselves. Most of the elixirs were poisonous pills. If no one tried the medicine, who would take it?

But some awesome Taoist priests went to the emperor to test medicine, just like dancing on the tip of a knife...

"I'm still alive? I'm afraid my death will last for one or two years." Qingyu secretly guessed in his heart that the Supreme Emperor's term may not be a few days ago, but this is not much involved with him.

He changed the topic and said with a smile: "Daojun, please, my alchemy room is there, and the alchemy Taoist can choose whatever he wants."

The group soon arrived at the alchemy room of Xingyun Temple.

The alchemy room is wide. In addition to a special alchemy furnace, the cabinet against the wall is like a medicine cabinet in a medicine shop, with all kinds of "cherished" materials placed.

"The alchemy materials in the entire Chang'an are the most prepared by Xingyun Temple." Qingyu pointed to the materials and introduced.

Some materials are simply not available on the market, so I can only search for them by myself.

Li Yuan nodded and began to search. He was considered an engineering dog in his previous life. Although he did not specialize in chemical engineering, there were still antimony compounds in his memory.

Not long after, he found it in the medicine cabinet. It was somewhat similar to tin, but after careful consideration, it was different. Then he used chemical knowledge to start purifying antimony.

After an hour, Li Yuan finally prepared three materials for making "lead movable type" copper molds, including lead, antimony and tin.

But this is still a thousand miles away from making lead movable type printing machine. After the materials are complete, if you want to make a copper mold, you first need to use a plastic clay mold, then mix the three metal materials in proportion and pour it into the mud mold. Only after polishing and polishing can you obtain enough lead movable type for use.
Chapter completed!