"I'm 466 years old. ”

As soon as Li Xuan's words fell, the expressions of several people on the table were extremely rich.

Vivien's mouth was wide open and she covered her mouth in disbelief. Egg's eyes widened in surprise. The three mages were much better, but they were all dumbfounded.

After a long while, Vivian asked weakly, "Teacher, are you really 466 years old?"

Li Xuan nodded to her seriously, and then the scene fell silent again.

Li Xuan looked at everyone and slowly said to them: "My situation is quite special, and when I have time in the future, I will communicate with you about this matter." Now that everyone is done eating, let's go to the third floor and start our first class there. ”

After speaking, Li Xuan wiped his mouth with a towel, pushed away the chair, got up and walked out of the restaurant. Egg, Vivien, and Master Sanming all followed quickly, and followed Li Xuan up the stairs.

After arriving on the third floor, Li Xuan instructed the maid Anna to move a few more chairs, because there were only 4 chairs in the pavilion, and there were 6 people with Li Xuan.

Anna quickly brought two chairs from the other bedroom, six chairs in a hexagonal circle, and six people sat down.

Li Xuan looked at a few people and slowly spoke: "There are many things around us, we can't see, touch, or perceive, but they are real, and there are many objects with one or more attributes. Think about it, what are the things around us that are like this?"

Several of them were lost in thought, but none of them could think of anything, and in the end none of them could say a word.

Li Xuan sighed, it seems that it will be a long time before they can really adapt to this kind of open communication.

"There are many such things around us, such as light, which we can see, perceive, but cannot touch, wind, which we perceive, but cannot see or touch, and air, which we cannot see, touch, or perceive, but which are very important to us. Li Xuan slowly carried out basic science popularization to them.

"Teacher, we can understand light and wind, but what kind of air are you talking about?" Bing Ge asked, and the others also looked at Li Xuan, indicating that they didn't understand.

Li Xuan was stunned for a moment, but quickly reacted, this world lacks specific detection and experimental methods, human mages pay more attention to magical wisdom and magic spells, and alchemy is not particularly popular in the human world, in Pisford's memory, only the tower mages in the extreme north are good at alchemy.

Li Xuan thought for a moment, stretched out his hand and waved in the void, and slowly replied: "The air is all around us, and we can breathe because of the action of air." The burning of the flame also occurs because of the involvement of a gas in the air called oxygen. ”

As he spoke, Li Xuan found that all of them looked like they were listening to the book of heaven, so he reorganized the language.

"In this space where we live, there are a lot of gases that we can't see, and these gases are very numerous, and all kinds of gases make up the air. Li Xuan said very slowly.

"Teacher, I know what you mean by air, but, what is gas?" asked Vivian with a cute look at Li Xuan.

Li Xuan frowned slightly, and couldn't help but sigh in his heart, this time it's troublesome, I still have to explain what gas is, it seems that there is still a long way to go. However, he did not feel discouraged, because he himself hoped to leave more of his former world civilization to be passed on here.

After thinking for a while, Li Xuan slowly replied: "In our world, most objects will have four states, that is, solid, liquid, and gas, and the other state is more complicated, and it will be difficult to explain for a while. ”

"I'll give you an example, you can understand that the water we drink, in normal times, we see liquid water, that is, liquid state. And when the temperature is very low, low to sub-zero, what happens to the water? It condenses into ice, and the ice is solid, that is, solid water. When we use pots, kettles and other containers to heat and roast with fire, the temperature rises, the water boils, and a lot of water will turn into gas in the boiling state, that is, those white smoke-like gases on the water surface, that is, gaseous water, that is, water vapor. Li Xuan was worried that they wouldn't understand, so he spoke very slowly, but this time they all roughly understood.

"In fact, in the mercury refining room in Carroston, the process used is to heat the solid mercury ore containing other impurities to turn the mercury into mercury vapor, and then use metal pipes to export the mercury vapor for cooling, and the liquid mercury is obtained after cooling. ”

In layman's terms, it is the temperature at which a liquid becomes a gas, and the boiling point of different substances is also different, and when we set the boiling point of water to 100 degrees, the boiling point of mercury is about 3.5 times that of water, about 350 degrees. Li Xuan said carefully.

"We're going back to the problem of air, a lot of gases that we can't see, make up air, and the composition of air is very complex because there are a lot of various gases. And the magic element, we can also think of it as a different kind of air, which cannot be seen, touched, or easily perceived. ”

"If you want to become a magician, the first step is to be able to perceive the magic element, and the magic element is extremely difficult to perceive the existence, there are some talented people, born with a very sensitive to the magic element, the affinity is very high, after proper learning, you can become a magician, such as Sid, Diribair and Bing, they are like this. Sid is sensitive to the air magic element, while Diribair is sensitive to the water magic element, and Bing Ge is sensitive to the fire magic element, causing the three of them to take the most sensitive elemental specialty to themselves in terms of magic element specialization. Li Xuan said seriously, he knew that the five of them might not be able to listen to much, but he would prepare some props and small experiments to deepen their understanding of the elements of magic, which would be of great help to their achievements and growth in magic wisdom in the future.

"Although there are not many things to talk about today, but you need to think more, especially Knight Egger and Vivien, you have not yet entered the threshold of magician, so it may be difficult to understand the knowledge in it, since you are already my student, I hope you can think more, and I will also help you step into the threshold of magician more. So, let's go here to-day, and we'll have a second lesson to-morrow morning, and you all go back, Sid, Diribair, Binge, are the servants below your apprentices? ”

"Our first class, that's it, the end of class. ”