After Li Tong left, Jiang Wei began to teach the villagers, telling them that if they put saltpeter in the water, it would freeze. And tell them not to eat ice directly, and teach them to make two buckets, one large and one small. Put saltpeter in large barrels and mung bean soup in small barrels.

Then teach them to boil mung beans and chill them, so that the chilled mung bean soup is freshly baked.

When the villagers tasted the chilled mung bean soup, they nodded their heads and said that it would not be too refreshing to have a bowl after the work. But I am still worried about whether I can sell it for money.

How much money is a mung bean? You can buy two catties for one penny per catty. In the Han Dynasty, a catty was 220 grams, and in the Tang Dynasty, a catty was 660 grams. The villagers are skeptical, how much can this be sold for?

Jiang Wei smiled,

"Don't underestimate this chilled mung bean soup, don't say anything else, a bowl for a penny, I think it will be quite easy to sell."

"What? A penny for a bowl? ”

At that moment, the villagers exclaimed one by one, their faces were incredible, a penny and two catties of things, you sell a bowl, who will buy this?

"Don't believe it, just this ice, that's something that can only be enjoyed today. Do you sell a bowl for a penny, is it expensive? ”

The villagers wanted to say that it was expensive, but when they thought that only the Son of Heaven could enjoy it, it didn't seem to be so expensive?

So they were all persuaded, Jiang Wei said that for every ten bowls sold, he would ask for a penny in dividends. The villagers also said that they had no opinion, after all, they had to sell it. If it is really sold, it will only cost a penny for ten bowls, which is too cost-effective. After all, the profits are too big, and the methods are all taught by Jiang Wei.

At that moment, Jiang Wei drew another picture, a hand-pushed unicycle, with a very simple structure. All made of wood. The villagers passed it on and looked at it, indicating their triumph. After all, carts already had in this era.

So the villagers began to divide the work in a hurry.

Women went to blacksmiths to make barrels and buy saltpeter and mung beans, and men went up the hill to cut down trees to make barrels and carts.

Three days later, everything was ready. The sky was not yet fully bright, and with the faint halo in the night, a couple and a trolley began to set off in the direction of Chang'an, like a long dragon.

In Chang'an City on this day, the sky was just dawning, and the hot temperature made the fan almost inseparable from his hand.

At the same time, in every street and corner of Chang'an City, there will be a different scenery than usual. Whether it was a student in a Confucian robe or a boy in silk, they all gathered next to a wheelbarrow, holding a large bowl and drinking cold mung bean soup.

And the men and women who sell mung beans are happy, four barrels of mung beans, and one bucket is sold in more than an hour, about forty bowls. How many bowls do these four barrels have to sell? The woman counted the copper coins in the bag of exactly forty wen, and suddenly her heart was full of joy.

In the afternoon, a carriage quietly appeared on the streets of Chang'an City. In the carriage, a woman with a noble spirit and a girl who looked like ten years old, puzzled by the fact that they found such piles of people every other way, cried out curiously,

"Uncle Fu, what's going on outside?"

The old man who was driving the carriage tightened the reins and probed,

"Lady, old servant, take a look."

Seeing the woman nodding, he got out of the carriage, and after a while the old man returned to the window.

"Lady, that's selling chilled mung bean soup, but you need to bring your own bowls and spoons."

At this time, the little girl couldn't help but speak,

"On such a hot day, why are there ice mung beans?"

The old man smiled bitterly,

"Little lady, this old servant doesn't know."

Although the woman was also curious, she hid something in her heart, so she said to the old man,

"Don't worry about it for now, go directly to Yunling Village, I don't know what happened to my poor nephew and niece, hey!"

Yunling Village, Li Tong returned to the door of Jiang Wei's house again, this afternoon, because the water froze, the master also began to doubt life, and finally did not come to class in the afternoon, so that Li Tong now appeared at the door of Jiang Wei's house, only to see the brother and sister squatting on the ground with a stone and playing an unknown game, it seems that the competition is to play who bounces into the pit first, and then plays the brain. Seeing this scene, Li Tong was speechless for a while, and wanted to turn around and leave on the spot.

It's so naïve.

But when I think of the picture of the water frozen, I can't open my legs.

"Brother, it hurts."

Ruoniang pouted and kneaded her already red head, and Jiang Wei laughed heartlessly, how do you look at this scene.

"Okay, okay, brother, let you play."

Ruoniang smiled happily and gently flicked Jiang Wei's head,

"Brother Jiang, Li Tong will see you."

"What's the matter?"

Jiang Wei didn't want to deal with him very much, first, he knew the other party's intentions, and secondly, he was having a good time with his sister, and he felt a little uncomfortable being interrupted. I didn't have a sister in my previous life, and I envy others for having a sister to bully. In this life, having a sister to bully herself is such an experience that is too rare. Well, in two words, it's very cool. Also, if you want to blame my sister, it's too cute.

Li Tong heard the other party's cold reply, but he was not discouraged, and took a deep breath,

"I want to know, why does saltpeter freeze when it is put in water? Please also inform Brother Jiang. ”

"This is the simplest kind of immortal art, and immortal art is knowledge, know?"

"Yes, you told me before."

"Hmm." Jiang Wei nodded, just wanting to send the other party away as soon as possible.

"And it is recorded in the fairy art that when saltpeter meets water, it will absorb the heat in the water, well... It's the water temperature, so that the water temperature drops, so naturally it freezes. ”

Li Tong frowned, racking his brains to think, his thinking seemed to be churning, as if in the clouds and fog, he didn't know the truth, but it seemed to make sense. Just wanted to speak again, but saw Jiang Wei waving his hand.

"Okay, that's all I can tell you, and you'll have to think of the rest."

Li Tong sighed, he understood that the other party was impatient, so he consciously bowed and turned to leave, but his back was a little gloomy.

Jiang Wei was also very helpless, after all, it was too troublesome to explain this thing, and the other party had no foundation, and he couldn't understand the detailed explanation.

"Brother, Ruoniang wants to eat ice mung beans."

Jiang Wei frowned, but looking at Ruoniang's pitiful appearance, his heart softened.

"If my mother is good, if I eat too many ice mung beans, my stomach will hurt, will I eat it tomorrow?"

"But Ruoniang's stomach doesn't hurt now."

Jiang Wei: ......

"Then tell my brother, how many bowls have you eaten today?"

"Three bowls..."

"You also know that you have eaten three bowls, and the rest will be eaten tomorrow, okay?"

"Not good."

Jiang Wei: ......

Ruoniang pouted and said pitifully,

"Brother, if my mother is not a child, will I eat a bowl? The last bowl. ”

Jiang Wei looked helpless, a nine-year-old child was saying that he was not a child, which was really unconvincing, but he really had no resistance to this lovely sister. At this time, an unfamiliar voice came,

"Is it Viagra?"