I was tired and sweaty and dug up seven or eight winter bamboo shoots as thick as an arm. I took them home and opened the shells to reveal the snow-white bamboo shoots inside. Cut them into boiling water to remove oxalic acid. I also cut them into small pieces of the washed beef and put them in a large pot of clay pot. Add pepper, ginger, garlic, garlic, crocus and fruit and sauce to simmer on the earthen stove.

Because of the iron pot and tea tree fruit oil, Chen Xu couldn't wait to go to the vegetable garden to pull out a basket of tender ginger vegetables. Xing'er and Shui Qingrou sat on a small stool to pick it up and wash it with water for later use.

Soon an hour passed, and a strong smell of beef was emitted in the kitchen, which could be smelled in the yard, and almost everyone felt saliva overflowing from their mouths.

"Brother, I want to eat braised beef noodles!" Xing'er could not hold it in anymore. She held Yu Ji's hand, and the two children were spinning around the stove, sucking saliva in her mouth.

"My benefactor, is it almost enough to cook noodles?" Yu Wuya kept licking his mouth, and squatted behind the kitchen stove from beginning to end, adding firewood and fire, replacing Xing'er's position on weekdays. Niu Dashi stood next to Chen Xu, and Wang Wu and Seven were also squeezed at the kitchen door, staring at the pottery jars that kept cooking beef, and drooling constantly. Chen Jiang, who cooks every day, was squeezed out of the door, and had to stand outside with Shui Qingrou and talk, looking happy, and the relationship between mother-in-law and daughter-in-law was very harmonious.

Chen Xu uncovered the lid of the clay pot and suddenly a strong aroma of beef spreads in the kitchen.

Chen Xu took a piece of beef from the jar with chopsticks and put it in his mouth. After chewing it carefully, he swallowed it a few times, a smile appeared on his face.

Braised beef noodles are just this flavor, and they are even more fragrant than what you eat in the noodle restaurant in the future.

"Gudong~" Swallowing sounds almost at the same time in the kitchen.

"Brother, I want to eat~" Xing'er shouted.

So Chen Xu took out a pottery bowl, scooped out two large spoons of beef and bamboo shoots from the pot with thick soup and handed them to Xing'er: "Be careful, take Yu Ji to the living room first and eat slowly!"

"My benefactor, I want to eat too!" Seeing Xing'er and Yu Ji leaving happily holding the pottery bowl, Yu Wuya couldn't help it.

"I'm so anxious. Add firewood and boil water. I'm going to cook noodles!"

"Hey, okay!" Yu Wuya nodded repeatedly and quickly added wheatgrass and branches into the soil stove.

"Delicious, so delicious! Braised beef noodles are indeed well-known, and it is really worth waiting for so long!"

More than ten minutes later, Niu Dashi, Yu Wuya, Wang Wu and six other men squatted on the steps at the kitchen door, all holding a large pottery bowl, and their chopsticks danced like windmills, eating one by one. Yu Wuya was still humming while eating, and the words of praise were beyond words.

A large pot of noodles and a can of bamboo shoots stewed beef, I ate it in less than half an hour. Even the beef soup was over. Almost everyone was overeating, and they all started to burp while touching their stomachs.

Chen Xu, water gentle, two little girls, Chen Jiangshi and Xinger and Yu Ji, sat on the kang in the living room, sitting cross-legged around the low table, eating slowly, not only eating beef noodles, but also a large plate of stir-fried cabbage, crisp and tender green, and the fragrance of tea tree oil, it is the most comfortable and satisfying time that Chen Xu ate after traveling over.

"This fresh and tender sausage is really delicious when stir-fried like this!" Shui Qingrou was particularly fond of the fried cabbage and praised it while eating it.

"That's natural!" Chen Xu was very proud and said while eating, "There are fewer vegetables in winter, everyone eat more."

Yu Wuya came in from the kitchen with a cup of tea, and while picking his teeth, he said, "What are the delicious green leaves? Beef and beef soup are really delicious!"

"Go up!" Chen Xu couldn't help rolling his eyes and continued to eat cabbage.

After eating for more than an hour, everyone was satisfied. The two little girls ate a big bowl of noodles. After eating, they went to play with each other.

Yu Wuya set up a chessboard on the kang and invited Chen Xu to kill several games of chess, but Chen Xu completely ignored it. Shui Qingrou also helped Chen Jiang clean up the dishes. Wang Wu saw that Yu Wuya was bored alone and wanted to flatter him for a few games. However, after less than ten minutes of the two left, Yu Wuya drove Wang Wu away, and then began to go with him, on the kang for a while, on the left and the right, muttering something in his mouth, looking divine and schizophrenic.

After drinking tea, Chen Xu felt that he had almost finished his digestion. He went down the kang to the laboratory to get things. But when he pushed the door in, he found that Xing'er and Yu Ji were sneakily hiding inside. When he saw him coming in, he was so scared that he threw down the things in his hand and ran out.

"Stop!" Chen Xu quickly shouted the two little girls, "What are you two doing here secretly?"

"Uncle Xu, we...we are not doing anything?" Yu Ji was so scared that she hid behind Xing'er's back and stuttered in a low voice.

"I said I want to call you brother!" Xing'er quickly reminded her.

Chen Xu's face was a little dark. Yu Ji called Yu Wuya's father, and she called Yu Wuya's elder brother, Xing'er called her elder brother, Yu Ji originally called her uncle, but her generation was messy when she called her brother, but Xing'er was happy to ask Yu Ji to call her brother, because she felt that she was about the same age as Yu Ji, but in this way, the generations in the whole family were completely messy, because Yu Wuya also called Chen Jiang's sister-in-law, Xing'er also called Shui Qingrou sister, while Shui Qingrou and Yu Wuya are senior brothers and sisters, so now the name of Chen Xu's family is completely messy.

"Brother Xu, my sister and I did nothing!" Yu Ji quickly changed her words.

"Really?" Chen Xu didn't believe it, but he was not very relieved, because there were too many unknown ores and materials in the laboratory, some of which were definitely poisonous, and the colors were colorful and beautiful. Once the two little girls were curious and poisoned, it would be troublesome. Therefore, this laboratory generally does not allow two little girls to come in.

"Really!" The two little girls nodded vigorously together.

"Don't lie, many things in the laboratory are poisonous and cannot be eaten. If you don't mean you are not allowed to eat tomorrow!" Chen Xu's eyes became very serious.

"Brother Xu, don't let me eat it. I want to eat delicious beef noodles!" Yu Ji grabbed Xing'er's clothes tightly, and her mouth slapped and stuck her head out crying.

"Brother, we didn't... we didn't steal it. We just accidentally found that the white powder in the bamboo tube would be thrown into the stove and there would be beautiful purple flames!" Xing'er also felt that Chen Xu was serious and handed a bamboo tube in her arms to Chen Xu in fear.

"White powder?" Chen Xu took the bamboo tube with confusion and opened it. It was indeed some white powder with mud inside. At the same time, he also remembered that the bamboo tube was made from the cave where Yu Wuya went to the Wild Wolf Valley to put wine. At that time, he thought it was gypsum or brine crystals, but as a result, he kept throwing it in a corner. He just thought that the bamboo tube that Xinger had was holding was filled with candy, so he didn't think too much about it.

"Purple flame?" Chen Xu was stunned for a moment while covering the lid. At the same time, a flash of lightning seemed to be shaking across the dark night sky in his mind, and he couldn't help but exclaim: "Flame color reaction~"

Chen Xu instantly remembered the simplest chemical experiment he had learned in high school chemistry class. According to the different colors of metal ions appear when burning in flames, some common metal compounds can be distinguished.

"Yes, Brother Xu, it's purple, so beautiful!" Yu Ji shouted in a timid voice, with a tear on her face.

What metal ion is purple?

Although Chen Xu had conducted chemical experiments on flame color reactions, after all, several years have passed, and suddenly I feel that my brain is not enough.

But since the two little girls said they were purple, he naturally had to verify it.

There are coal blocks in the small stove in the laboratory, and a lid is made of yellow mud. It is usually covered to make the coal burn as slowly as possible, just to make the laboratory warmer. At the same time, sometimes Chen Xu needs to heat up some things and can use them at any time, but the yellow mud lid on the upper has been unveiled by two little girls.

Chen Xu poured out some white powder and threw it into the stove. Sure enough, a purple smoke suddenly emerged from the coal fire.

"Brother Xu, have you seen it? Sister Xing'er and I didn't lie!" Yu Ji suddenly pointed at the stove with her little finger excitedly and shouted.

"Xing'er, take Yu Ji to the living room for fun. Don't come in without my permission in the laboratory!" Chen Xu waved his hand and asked Xing'er to take Yu Ji away.

"What kind of metal is purple?"

After the two little girls left, Chen Xu threw some of the white powder into the coal stove. Looking at the burning violent purple smoke and a slightly pungent smell, he pinched his chin and began to rack his brains to recall the high school flame reaction experiment.

Flame color reaction is the color produced by the combustion of various metal ions in the flame, but not all metal ions can be observed. There have been several experiments in high school chemistry class, which are to stick various mineral salts or oxide powders on iron wire or glass rods to observe under an alcohol lamp, so as to roughly distinguish the types of metal ions contained in the compound.

The sodium ions are yellow, Chen Xu remembers the most clearly because after taking the chemistry experiment class, he also stole half a bag of pure salt used for the laboratory for experiments.

The magnesium is white, and the magnesium lamp used in old-fashioned cameras uses this principle, which can be easily recalled. As for the others, they still remember them slightly, but they are not very clear.

Chen Xu sat in front of the window and recalled for a long time and picked up the brush.

The sky became darker and darker, and the room was getting darker, but almost half an hour passed, and Chen Xu also wrote several metals with flame-colored reactions on the paper that could be remembered.

Sodium: yellow, copper: green, magnesium: white, calcium: red, cobalt: blue.

These are the most common types, such as copper ions, which become green after oxidation, which is also the origin of bronze. Whether it is burning or aqueous solution, copper ions are green.

Cobalt is used in the glass industry, and the common cobalt glass is blue. When observing the flame color reaction, every student sent a blue cobalt glass sheet.

Chen Xu suddenly remembered something. If you remember correctly, this purple one should be potassium ions. Because when I think of cobalt glass, the teacher mentioned that the flame color reaction of potassium ions is best to be observed after filtering through cobalt glass, because sodium salt and potassium salt are often mixed together, and cobalt glass can filter the yellow color of sodium ions.

The white powder burns directly into a very rich purple color, so it can basically be concluded that this is a very pure potassium salt.

Chen Xu was excited and had a headache.

There are too many potassium salts in nature. Is it potassium nitrate, potassium carbonate, or potassium sulfate, potassium phosphate, and potassium chloride?

After thinking for a long time, he suddenly remembered that the temperature of the cave was very low. In the summer, it was more than 30 degrees outside and only more than 10 degrees inside, and the water was extremely cold.

Chen Xu couldn't help but thrust hard for a few times. He quickly found a cup to fill half a cup of water, put his fingers in and felt it, and then poured some white powder in. Soon, he could feel the pottery cup becoming colder and colder without reaching in.
Chapter completed!