"Yes, is the murder weapon a glass product? But what kind of glass product can have such a great hardness? The human skull can be said to be one of the hardest bones in the human body, and the murder weapon can smash the skull, so it must not be glass, right?"

"Wait a minute," Durin pulled out his phone, "I'll look up the internet to see what glass is the hardest." ”

Duhrin opened the browser on his phone and typed "the hardest glass" into the search bar, and a lot of results came up below.

"Tempered glass has a high hardness and is often used in glass curtain walls, but when it is hit hard, it will still break, and it itself has the possibility of self-explosion, so it is unlikely to be tempered glass.

There is also a super glass invented by scientists in the United States, this kind of glass has added some metal elements such as silver and palladium, which is very hard, but this thing is only in the laboratory, and it is unlikely that ordinary people can get it. ”

Li Xian was also checking his mobile phone, "What is this Rupert tears? It is said that when the bullet hits, the glass is fine, and the bullet will shatter." ”

"Oh?" Dührin also typed "Rupert's tears" into the search bar on his phone, and a row of search results appeared, and the first one was an encyclopedia about the term.

Historically, there was a Prince Rupert in England in the 17th century, who had a very rich spare time, he was a nobleman, but he was also a soldier, a general, a scientist, an athlete, The colonial governor and amateur artist, who once made a glass artwork as a gift to King Charles II of England, said that the head of the glass could withstand repeated hammering and was intact, but the tip of its tail would instantly shatter into a piece of powder if it was gently pinched.

The specific method is to use a large drop of red-hot glass to fall in a bucket of cold water in a free fall manner, and after the liquid glass cools quickly, it will form a tadpole-shaped glass crystal.

At that time, people did not understand why the glass made by this method would have such magical properties, and it was not until later generations of scientists gave a scientific explanation: when the red-hot glass drips into the cold water, the outer layer of glass quickly cools and solidifies, forming a hard solid glass shell, while the internal glass cools slowly, and the volume shrinks during the solidification process, resulting in a large compressive stress on the glass near the surface, and at the same time, the core position is also pulled around, subjected to tensile stress, so that the two stresses form a balance at the head of this tadpole-shaped glass, which can withstand huge forces, and the bullet will not have any damage on it, not to mention using a hammer, even if it is squeezed with a hydraulic press, the injured can only be a hydraulic press.

This kind of glass is not without weaknesses, because in the process of natural fall, the last part into the water will definitely form a slender "little tail", this part is very fragile, as long as this small tail is broken, it will destroy the stress balance of the whole glass, and the result is the whole piece of Rupert's tears instantly shattered powder.

Like those shards of glass that had just been found on the site of the crime.

Durin seemed to suddenly remember something, he walked to the bookcase in the living room, raised his hand and took down the top of the bookcase, there is a groove on the base of the shelf, it seems that there should be a nameplate here before, Durin reached out and touched the top of the bookcase, sure enough, he touched a metal piece, take it down and take a look, it should have been put for too long to degum, fell off the base, only to see the metal sheet written on it: "The product of tensile stress and compressive stress - Rupert's tears".

The deceased, Yan Jitian, was an associate professor in the Department of Physics of the university, and it was considered a "professional counterpart" for someone else to give him this thing as a gift.

Durin turned the base over and saw that a capital letter "Q" was written in black marker under the base, and in general, people would write their names on the back or bottom of the gift so that the recipient could remember who gave the gift.

So is the "Q" an initial letter of the giver's name, and is the giver related to the case?

Du Lin and Li Xian both felt that they were getting closer and closer to the murder weapon and the murderer.

"Lao Li, where is there a factory or workshop in Zhonghu City that makes glass crafts?" Although they are already ninety percent sure in their hearts, the glass crafts Rupert's tears that were originally placed on this shelf are the murder weapon, but they can't use the information found on the Internet as evidence, and if they want to go to court, they have to come up with a solid evidence.

"Well, this kind of factory or workshop is unlikely to be in the urban area, but there may be one in the surrounding townships," Li Xian tried to recall in his mind, "I remember, I remember the last time I went to Yongchuan to handle the extermination case, when I was fishing for shoes in the river outside the town, I seemed to see a factory in the upper reaches of the river with a glass handicraft processing factory written on it." ”

"Yongchuan?" Du Lin thought for a moment and called Gu Amei.

"Sister, let me ask something, you lived in Yongchuan for a while, do you remember that there was a glass processing factory in the upper reaches of the river east of the town?"

Gu Amei on the other side of the phone said with great certainty: "Yes, I have an impression, but what are you going to do there? That place is haunted." ”

If it were another person who said where it was haunted, Durin might laugh it off, but if the person who was haunted was Gu Amei, it would be 100% really haunted.

Because others say that the haunted may be a snake shadow with a cup of bows and a faint eye, or it may be hearsay, or it may be a false rumor, but Gu Amei is a superhero "ghost-eyed man" with yin and yang eyes.

This nickname was given by Pique, and he felt that Gu Amei didn't have a title that was too inconsistent with her superhero identity, so he gave her a name, but at first it was called "Ghost Man", but it was blasted by Gu Amei's small fist, and later changed to "Ghost Eye", which barely satisfied Gu Amei.

"Then sister, are you free? Go to Yongchuan with me and Li Xian?"

"This ...... All right. Gu Amei hesitated, but still agreed.

Pique drove the "pseudo Passat", pulled Gu Amei to the scene of the crime, and took Du Lin and Li Xian to Yongchuan Town.

Now that Peake is with Gu Amei every day, Du Lin feels that he has not found a bodyguard for himself, but a boyfriend for Gu Amei to come back.

Yongchuan Town is still the same, not much different from the last time I came to investigate the extermination case, Gu Amei is not in a good mood, this Du Lin understands very well, for Gu Amei, there are too many bad memories here.