This time I went back to Ruicheng for the New Year, Liu Pengcheng actually didn't have anything to do, since he had a mobile phone, the difficulty of communication was greatly reduced, he could talk about anything on the phone, and he mainly went home to see his family.

In two days, Liu Pengcheng walked around most of his relatives, and in the evening he ate with friends.

On the third day, Liu Pengcheng took his wife and children directly, went straight to Xidu, went to see his father-in-law's family, and planned to live in Xidu for three days before returning to Ruicheng.

Xiao Gu's phone call before did not encounter a breakthrough, but mainly concerned about Liu Pengcheng's journey. As a driver, of course, he was worried about the safety of Liu Pengcheng's driving, but after chatting about his daily life, Xiao Gu still reported a new matter to Liu Pengcheng.

Haunted again.

This time it was not quite the same as before, there were no physical ghosts, and no substantial damage was caused.

Feng Fatzi is good to workers, which is still a little famous in the industry. Feng Fatzi's side, there are two rules, first, take care of the rice! Breakfast and lunch, dinner alone! Second, each worker will be given one egg in the morning and noon, two eggs a day!

The problem lies in this egg, when eating in the morning, some workers saw some crooked and oblique symbols on the eggs, and asked those who knew the word, and they looked at it carefully and found that it was written on the Chinese character "ghost".

When I found it, the eggs had already been skinned, and all kinds of crumbs were thrown on the ground, so the handwriting was not very clear. Later, I checked and found that at least six eggs had this word on them, not exactly the same, but they were all the same word.

The characters are not written with a pen, as if the eggs themselves are revealed, the word "ghost" probably covers half of the egg, and the font part appears a little brighter than the other parts, but other than that.

The workers were so frightened that no one dared to eat the eggs, and they threw them all away. By the time Xiao Gu found out about this and found the eggs, there were still two eggs with words that no one dared to eat.

The workers were afraid, but of course Xiao Gu was not afraid, he contacted Liu Pengcheng as soon as possible, and Liu Pengcheng knew that this was a chemical problem, so he asked Xiao Gu to take the egg skin to Professor Xu.

This kind of pediatrics has no need to study in front of Professor Xu, and the answer is directly given - vinegar.

To put it simply, use scissors to cut a thin layer of plastic tape, like a paper cut, cut out horizontal and vertical skimming, and then stick it on the egg to form a word.

After pasting, put the eggs in a bowl of vinegar, take them out after 20 minutes, and remove the tape, so that two distinct colors are formed. This color difference is not caused by the brush alteration, so it cannot be washed off or cooked.

Professor Xu even demonstrated to Xiao Gu in person, cutting down the word "god", although Professor Xu's paper-cutting skills were average, but the experiment was still very successful.

With this "god" egg in hand, Xiao Gu returned to the construction site again and showed it to Feng Fatzi. Feng Fatzi was like a treasure, he knew that it was unrealistic to talk about chemistry to the workers, so he said that he invited immortals, so there was no need to be afraid of ghosts!

This "god" egg was left at the gate of the construction site, and the workers were naturally not afraid.

The construction of the air-raid shelter went smoothly, and on the third day after the "ghost" incident, all the cleaning and installation of electric lights were completed. In other words, at present, there is no debris and garbage in the entire air-raid shelter, and it is brightly lit! In this way, there is nothing to be afraid of ghosts. According to the current estimate, it will be completed before the Chinese New Year!

Spring festival!

For workers, they can get money to go home for the New Year after they are busy with this order, which is beautiful!

Liu Pengcheng has always paid attention to Yu Hang, but he has never been in a hurry to go back, and he also told Xiao Gu that he doesn't have to worry too much about this matter, just rest when he should rest.

It wasn't until the third day after he returned to Ruicheng from Xidu that Liu Pengcheng received a call from Xiao Gu again.

"What's new?" Liu Pengcheng is still a little curious, he knows that the project is progressing smoothly now, is it possible that it can still be haunted now?

"Brother Liu, I've been checking for so many days, and finally let me find something different!" There was a hint of excitement in Kotani's voice.

"Is it convenient for you to talk over there?" Liu Pengcheng reminded.

"Convenient, I'm at school!"

"Back to school?" Liu Pengcheng was a little puzzled.

"Hmmm! I'm with Professor Xu and Professor Luo. ”

"Professor Luo is here too?" Liu Pengcheng was a little puzzled, Professor Xu was normal in his mentor, but Professor Luo was not normal, after all, he was already on vacation.

"Well, I'm here too," Professor Luo took the phone, "Recently, there was a case in Yuhang, which happened to involve the Fourth Hospital, and I was invited to come over for an appraisal, so I met Professor Xu, and I ran into Xiaogu's case, so I chatted." ”

"Wait a minute," Liu Pengcheng was a little surprised, "Is there a murder case in the Fourth Court?" If that's the case, I should know! ”

"It's not a homicide, it's a medical accident, the family of the deceased thinks that the hospital treatment process is unreasonable, and complained to the Health Bureau, and the case is now supervised by the Ministry of Health. Professor Lok explained.

"So it's an old case?"

"Well, it's been two months."

"Then how did today's case involve you?" Liu Pengcheng asked again.

"I'll tell you," Kotani said, "Director Liu, here's the thing. I also told you about the things a few days ago, since the egg made by Professor Xu was laid out, the follow-up project is also very smooth, although I didn't find out who put those eggs, but no one made trouble, and today, the electricity in the air-raid shelter has been laid. However, when digging the water pipe tank today, I kept an eye on it and checked all the things that were chiseled, and I found a problem, the stones chiseled out in several places were obviously more humid, I took samples and looked at Professor Xu, and he said that these stones were badly corroded, not like natural corrosion. ”

"You mean, there are a few rooms where the entire floor has been corroded?"

"Yes, including the house where we found the bottle of 'Celestial Liquid'."

"What does Professor Xu mean?" Liu Pengcheng asked.

"I went to those houses today to do a field survey, and although they were cleaned, I still found traces of erosion on the ground. Very slightly, I took a little sample and found a gypsum component, which covered the surface of the marble with a very thin layer, which I presumed was once sprinkled with sulfuric acid. Professor Xu explained.

When I was in middle school, I learned that the reaction of hydrochloric acid with marble (the main component of calcium carbonate) can produce calcium chloride and carbon dioxide, which is also the way carbon dioxide is prepared in the laboratory. Sulphuric acid reacts with marble, on the other hand, because the resulting calcium sulphate (the main component of gypsum) is insoluble in water and forms a protective layer on the surface of the marble. (End of chapter)