"You little girl, you know how to make fun of me." Xia hit Yan Lin and said in frustration: "Well, if I really change my name, it would be nice if the weather wouldn't be so hot. I can make ice. Whatever makes Wu feel more comfortable."
"Ahem."
Yang Cheng coughed, and these two little girls really didn't believe what he said.
"Why not? In fact, making ice is very simple. You just need to find one thing!"
Hearing Yang Cheng's words, Xia and Yan Lin both raised their heads and pricked up their ears.
"Witch, what?"
"Nitre."
"Nitre? What is that?"
"A colorless, white or gray stone, the kind that reflects light."
"Stone, like copper ore?"
"Almost, it's a special stone that can be mined."
"Okay, I'll go talk to my father and the others and ask them to find such a stone."
After Yan Lin finished speaking, she ran away excitedly.
After a while, Yanhu and the others, who were lying on the bamboo mat in the distance, groaning and stroking their full bellies, became excited one by one, and then ran towards here.
"Witch, are you telling the truth? You can make ice with that kind of stone called saltpeter?"
Yan Hu looked at Yang Cheng expectantly, and behind him, the others also looked expectantly.
"Yes, you can make ice with saltpeter." Yang Cheng nodded and smiled: "But saltpeter is difficult to find. I have looked for it near the tribe before, but I couldn't find it."
"Is that so?"
When everyone heard this, their expectant faces suddenly dimmed a lot.
However, Yan Hu laughed and said: "Wu, it's okay. Since there is this thing called saltpeter, and Wu you said it can be used to make ice, then let's go look for it. Anyway, it's just a matter of looking around. It's not troublesome. , do you think so?"
Yan Hu's last words were addressed to everyone.
Everyone agreed when they heard it. It was just a matter of spending more time, and they happened to have nothing else to do except build the wall.
When making a fence, pay more attention when you go out to collect stones, and you might be able to find them.
Yang Chengduo glanced at Yan Hu, but he didn't expect this guy to be able to inspire people.
"Well, let me tell you about the shape of saltpeter. Please pay attention."
Yang Cheng told everyone about the characteristics of saltpeter, then thought about it and said, "Let's do this. If you are not sure, just find a similar stone and show it to me."
"good."
Everyone responded and left with great expectations.
Yang Cheng heard from a distance that when they left, they were still discussing ice, saying how refreshing it would be to drink ice water if you put ice in the water. Others said that if you put ice in the water, you can take an ice bath. , some people even say that when sleeping with your wife at night, you can use ice...
Ahem, do primitive people also like to play this kind of tune?
Yang Cheng looked strange and stopped listening to these inappropriate things.
The night is as dark as water and dotted with stars.
After the night got a little deeper.
Most of the people took a short rest and then went back to their houses, while a few people did not believe in evil and began to search the Qingque tribe.
These people are all second-class citizens. They know that this is a good opportunity to accumulate "contribution points". As long as they find this stone called "saltpeter", they can become first-class citizens and receive the same treatment as the totem warriors.
Yang Cheng didn't reveal their little thoughts.
They have this enthusiasm, which shows that the citizen level formulated by Yang Cheng is very good and the effect is remarkable.
But as they waited, they discovered a white substance near the toilet, which was very similar to the characteristics of the saltpeter Yang Cheng just introduced.
Then he ran over and asked Yang Cheng if this was saltpeter.
Yang Cheng coughed twice and said without blushing or heartbeat, this was either saltpeter or a simple stone.
These second-class citizens left with disappointed faces, but they were not depressed either.
Didn't the witch just say that he didn't find any saltpeter near the tribe?
And if the saltpeter was found so quickly, why would the witch still have to look for it for so long? Would he still be a powerful and mysterious witch in their eyes?
In fact, they didn't know that they really found the right one just now.
Those white stones next to the toilet are saltpeter, but they are not saltpeter mines.
Urine contains urea, CO(NH2)2, the main nitrogen-containing substance in human and animal urine, which is a metabolic product of protein.
In livestock and poultry excrement and human excrement, it contains about 0.05-0.2% of urea.
Moreover, wherever urea exists, urease, which decomposes urea, also exists.
Under the action of urease, urea decomposes NH+4 ions, which can also be converted into "nitrate" (NO-3) ions by nitrifying microorganisms.
Therefore, as early as thousands of years ago, people on the earth have known to get "nitrate" from the toilet side or the wall soil where urine is easy to accumulate.
However, Yang Cheng definitely did not admit that these white things were made of "nitrate". The reason was very simple. Yang Cheng found the saltpeter to make ice.
Ice is meant to be soaked in water for drinking. If the saltpeter found next to the toilet is used to make ice, Yang Cheng always feels that something is a little weird and he can't accept it.
Early the next morning.
The people of the Qingque tribe set off, and everyone was very interested in finding the stone called "saltpeter" that Yang Cheng said.
Not just them, the slaves of the Qingque tribe also lit up when they learned that the witch had issued another order. With this in mind, they would pick up white or gray stones when they encountered them while working. Look at it, then hand it to the overseer.
The supervisor will check whether it is saltpeter. When the totem warrior responsible for guarding the slaves is not sure, he will find Yang Cheng and ask if it is saltpeter.
The slaves got a negative answer every time, but they rekindled their hope every time and continued to look for stones carefully.
Second-class citizens yearn for first-class citizens. Why didn't slaves want to become second-class citizens?
However, their idea was in vain. Yang Cheng planned to consider absorbing them into third-class citizens after they were released from prison, which was one level lower than second-class citizens.
This is something that will happen in the future. The slaves will have to work in the Qingque tribe for several years before they can be released after serving their sentences.
What Yang Cheng is thinking about now is, besides using saltpeter to make ice, what other ways are there to make ice?
Yang Cheng grabbed his hair with his hands and thought distressedly about the ancient methods of making ice that he had seen in those science and education TV shows and books.
The most common thing is to dig a cellar to store ice.
This is the simplest and easiest way to implement.
In the winter, ice is dug on the river, placed in a sealed cellar, and opened in the summer.
"Oh, why do I forget things so easily? Why don't you build an ice cellar in winter? Wouldn't it be much better to have an ice cellar?"
Yang Cheng felt a little regretful, but regretting was of no use.
He could only continue to think about whether there was any other way.
Not to mention, after Yang Cheng's hard thinking, it really reminded him of an ancient method.
