After coming out of school, Wang Yang looked at other buildings and found that many buildings had begun to use wooden beams.

We are testing whether it will be more stable.

"You made the beams, but did you make the foundation for the house?" Wang Yang suddenly asked.

Zhang San replied: "According to the geography book, there is not much moisture in the soil on the savanna, and the land is compacted. As long as there are no earthquakes, there is no need to build a foundation, so there is no need to build a foundation here."

"But the foundation was laid on the wheat field. That side is close to the river, and the deep soil is relatively moist, so the foundation was laid."

Wang Yang nodded and explained: "If you want to build a second floor or even multiple floors in the future, you'd better lay a foundation."

Zhang San nodded without thinking deeply. They had never wanted to build a house with more than two floors. It was not because they lacked land, so why bother doing such a thankless thing.

At the end of the day, Wang Yang visited the tribe's house. He saw many things and even the laboratory.

After studying chemistry, they know that pure table salt is sodium chloride, and there are other impurities in it, and they are extracting the other impurities.

This not only purifies the salt, but also adds an additional chemical substance, which can then be reacted and extracted to create new chemical substances.

Over time, you can complete the collection of various substances in the chemistry book and then use them.

Wang Yang found it very interesting and watched them making it.

I saw them taking a piece of coarse salt without any processing, putting it into a small bowl, dripping some water into it, and taking out the salt after a while.

That little water was poured into the big wooden barrel.

Wang Yang felt a little dizzy. He didn't know what they were doing, so he stepped forward and asked, "What are you doing?"

One of them came up and said: "Extract magnesium chloride."

Wang Yang knew that magnesium chloride is also a salt. But it is not table salt. Table salt is sodium chloride.

"You can extract it like this?" Wang Yang was very confused.

They nodded: "It should be extracted. The chemistry book says that when the indoor temperature is about 20 degrees, the solubility of magnesium chloride is higher, and the solubility temperature of table salt is very low."

"In other words, if water drips at this time, the magnesium chloride will dissolve, but the table salt will not dissolve."

Wang Yang was stunned for a moment after hearing this, and he couldn't help but said in surprise: "Did the chemistry book teach you how to extract magnesium chloride? I don't know much about it, so don't lie to me."

They shook their heads: "The chemistry book doesn't write it directly, but it does write about their solubility at different temperatures. Once we convert it, we can almost calculate it."

"Uh... I'm a little dizzy, Zhang San, hold me up."

Wang Yang felt very defeated. It was indeed the case, but he had never thought about this. Anyway, he took the liberal arts exam, and all the science knowledge was memorized back then. He never thought about it deeply.

Now that this group of primitive humans say it, I feel a little confused in time and space. I have been emphasizing on drawing inferences from one example, but in the end, the primitive people learned it and forgot...

But Wang Yang still had questions: "But how do you know it's twenty degrees now?"

Everyone shook their heads and said: "We haven't made a thermometer yet, so we can only test it every day and make clumsy records."

After saying that, he touched his head in embarrassment, with a look of shame on his face.

"Well...this...is indeed the case, but how can you be sure that the dissolved magnesium chloride is not salt?" Wang Yang asked again.

Everyone looked at Wang Yang inexplicably: "Because magnesium chloride is bitter. You will know it once you taste it."

Seeing Wang Yang's stunned look, everyone was even more confused. Isn't this common sense? Why does it look like Wang Yang doesn't know?

But thinking about it carefully, everyone felt ashamed. Those books were all written by Wang Yang. How could Wang Yang not know? He must be testing them! Or he was depressed about why they used such stupid methods.

"We are too stupid. We can only test at each time every day and judge the temperature based on this. Otherwise, you, old man, will teach us another method? We are so embarrassed that we are embarrassed to go out and tell people that you personally taught us...

…”

Everyone looked guilty and ashamed...

"Say! Why can't you say it! You must tell others that you were taught by me! Although your method is indeed stupid and not good, how can I dislike you just because you are stupid! I will not give up on you.

!Shame on you all!”

Wang Yang expressed his expression with a serious look on his face, not blushing at all, which moved the group of people to tears.

"Ahem... I won't say much more about this. How do you plan to use magnesium chloride?" Wang Yang asked.

"Oh, according to the combination of biology and chemistry, the composition of paper is... so it can be added to paper to make paper, and then according to the combination of biology and chemistry, magnesium chloride can be used as a food additive, please explain

I’ve talked about what food additives are, and also talked about the ingredients, including magnesium chloride, and then based on..."

"Stop, you continue! I won't disturb you anymore!"

Wang Yang hid his face and fled, secretly vowing that if he ever travels back to modern times, I promise not to kill anyone who says primitive people are stupid!

In fact, this should be considered unexpected. It is reasonable. Those few people have studied chemistry very well. They probably have better brains and strong talents.

Of course, the most important thing is to teach well! Wang Yang said to himself.

"Eh? Wait! There's something wrong here!" Wang Yang suddenly woke up and turned to ask Zhang San.

"They extracted something similar to magnesium chloride from salt. Doesn't that further make the salt purer?"

Zhang San was a little confused. He was not very interested in chemistry, so he turned to ask an adult next to him, and then said to Wang Yang with a smile: "Well, yes, the salt has become purer and more suitable for human consumption.

"

"Well, very good, very good, these guys are good. When did they refine magnesium chloride?" Wang Yang asked as he walked forward.

Zhang San asked the person behind him again, and then said to Wang Yang: "Just a few days ago."

"Well, it's pretty fast. You must have wasted a lot of salt and time?" Wang Yang was in a happy mood, with a proud look as if he had extracted magnesium chloride.

Zhang San hesitated, but still said it: "They spent more than three months and wasted a thousand kilograms of salt."

"Well, more than three months, the time is very short, one thousand kilograms, not much, wasting some is... what! What do you say! They wasted a thousand kilograms of salt before extracting magnesium chloride for me!!!

"

Seeing Wang Yang's sudden change of color, Zhang San said with a bitter face: "Yes, they wasted a thousand kilograms of salt, an average of ten kilograms every day, and finally figured out how to extract magnesium chloride."

"For this reason, the osteologist has scolded them many times, and it hurts me so much, saying that they are too bastards, too..."

Zhang San's voice became smaller and smaller, because he saw Wang Yang's face getting more and more ugly, and couldn't help but wink at a few people around him.

Those few people consciously and silently stepped forward to block Wang Yang's path. They obviously did this often and were very skilled.

"I'm going%￥#...! One thousand kilograms of salt! Do you know what it means? That's two thousand kilograms of salt!"

"It's so wasteful to find a way to extract magnesium chloride! There are other ingredients in the salt. If they extract them all, they will waste all the salt mountains!"

"Prodigal son! Damn it! Let me see if I don't skin them!"

The more Wang Yang talked, the more excited he became, and the more he cursed, the more excited he became. He threw himself back, and the people around him immediately hugged him skillfully. They were secretly happy in their hearts: "Fortunately, I am a bone-grabber like this all the time."

After scolding for a while, Wang Yang finally lost his temper and continued to walk forward, swearing secretly.

If we travel back to modern times, whoever says that primitive people are smart, I promise not to beat them to death!

It was night, and everyone knew that Wang Yang had come out. They all gathered around him, only daring to watch curiously but not daring to speak.

Most people have never met him, and he has never met most of them, so he can only say hello one by one.

They were very enthusiastic and came forward to talk to him with pens and papers and said their names.

Wang Yang was very surprised: "Did you choose the name yourself?"

Everyone nodded vigorously to make it easier to remember.

Wang Yang thought about it, and then tried to remember their names. They seemed to like to use numbers to name their names. Some were called '1', some were called '2', and some were called '3'.

Good guy, I will be in trouble in math class in the future. Just say a number and someone will stand up and say, "Here we go!"

What particularly impressed Wang Yang was the ingenuity of some guys, who were called "2 noses", well, they were pretty cool, and they were also called "2 dogs", and they really lived up to their names.

Wang Yang felt dizzy after remembering it for a while, so he simply found Zhang San and asked him: "How many people are there in the tribe now?"

Zhang San asked someone to bring a small notebook, and there were only two words written on it: "Number of people."

Each page shows the population of the tribe that year.

"The tribe now has 2,500 people. There should have been more people, but there are also 2,300 people who died of old age and accidents."

"Well, almost." Wang Yang did some calculations and knew the population growth in the past five or six years.

If you take that book over, you can see the annual population growth, the number of children, and the number of labor force.

Turning another page, there is also a very detailed record of how many people are assigned to various tasks.

"Good job. I don't have time to do this. You remembered it all?"

Seeing Wang Yang's smile, Zhang San knew that Wang Yang was very happy, but he still shook his head and said: "I didn't do it, it was Li Si. Look at the fan shape he drew, it's very standard." As he said that, he also took out a protractor.

Come and measure...

"I won't read these." Wang Yang looked at the book silently and sighed secretly in his heart.

"If there is one generation every six years, now the fourth generation has been born, the third generation has joined the workforce, and the second generation has become the backbone of the tribe."

He suddenly said to Zhang San: "Do these young people in the tribe behave differently?"

At the beginning, the second generation of young people all had signs of wanting more resources. It is hard to imagine whether there would be any trouble now that the fourth generation is here.
Chapter completed!