"Got it! Hahahaha......" Lu Yuanzhi suddenly laughed, and said without thinking: "As long as the tin is slightly hot, it will melt, Shi will always burn the fire in the cabin, melt the tin, and pour it into the river through the hole!" ”

Oh, I see! Everyone nodded their heads in a state of sudden realization.

Qin Lin laughed to himself, of course, what the fat man said is also a little reasonable, the melting point of sterling silver is more than 960 degrees Celsius, and the melting point of tin is only more than 230 degrees - there is this temperature when the oil is heated to seven or eight percent when stir-frying vegetables at home, so it is just possible to use a pot to "fry" the tin out of the dry sand mud.

Compared with silver with a high melting point, tin can be melted with only a little heating, and it is indeed easy to drain out of the cavity, but the fat man's conclusion has a key point that does not make sense!

Zhang Zixuan was the fastest among the crowd, and immediately questioned: "This seems to be a little unreasonable, it is true that the tin will melt as long as it is slightly heated, and it can be discharged from the cavern, but there is no trace of fireworks in the secret cabin, let's not care where the wood and coal come from, just say that they are burning in the secret cabin with only two small ventilation windows, and they are not afraid of burning themselves to death?" ”

The fat man grabbed his hair with great difficulty, and suddenly thought of what he had learned through the secret visit, and explained like a cannon: "I see! When I got up at night, I heard the officers and soldiers coughing in the secret cabin, and they were smoked by the smoke! The fuel used to heat the tin ingots was actually the liquor that Cui Sicang secretly transported to the cabin, and the old army saw the fish leaping over the dragon gate, because the molten tin was poured into the bottom of the river, and the fish jumped out of the water in shock! ”

Lu Fatzi only felt that he was analyzing the slightest detail, and laughed proudly: "Hahaha, it turns out that I am so smart...... Brother Qin, I didn't say anything wrong this time, right? ”

Ahem, Qin Lin smiled and touched the fat man's head, "Child, you can tell the wrong inference as the truth, you are bright!" Think about it carefully, how big a wine gourd is needed to burn and melt the entire 500,000 taels of tin ingots, and these melted tin, as soon as they enter the river, form a lump again, how can they not be salvaged and dissolved in the silt? ”

The fat man shrunk his neck and laughed dryly, knowing that he was reasoning in the wrong direction.

"Tin plague, Brother Qin, it must be tin plague, right?" Zhang Zixuan's radiant eyes looked at Qin Lin, I don't know if it was blown by the north wind, or because of the excitement after finding the answer, the beautiful goose egg face was flushed with a seductive flush.

Qin Lin nodded, this is the correct answer, the disappearance of the tin ingot in the cabin is not because of the high temperature heating, but it is closely related to the rare cold in Yangzhou.

There are three allotropic forms of tin: white tin, gray tin, and brittle tin. Tin can have different crystallization states in different environments. At room temperature and above room temperature, the most stable form is white tin, white tin is a malleable metal, often used by people to make tin, wine pots, tea cans or something, Tang Seng's nine-ring tin staff is also this thing.

When the temperature is as low as -13 degrees Celsius, the crystalline lattice of tin will be rearranged, and the gaps between atoms will increase, forming a new crystalline form, that is, gray tin. The internal stress that occurs at the contact between the different crystalline lattices of the gray tin causes it to break into powder.

The silvery-white tin with good ends loses its luster and turns dark gray at low temperatures, and crumbles into powder, and this "plague" of tin will also be transmitted to other "healthy" pewter, and a piece of tin ingot becomes ash powder, and the ash powder is sprinkled on the tin ingots that have not yet been transformed, and soon all of them become ash powder, as if the epidemic is contagious, and people observe this phenomenon, so it is called tin plague.

Tin plague is often seen in the cold areas of the north, but Yangzhou is warm, and people rarely see it, so no one thinks about it, how do you know that the result is so unexpected?

(Cat's note: the weather in Yangzhou is mild, but there is also a low temperature record of minus 20 degrees Celsius in 1918, which is colder than minus 13 degrees Celsius when tin plague was produced) The southerners present did not quite understand, and those who had experience in the cold areas of the north suddenly understood, Huang Gonggong sighed and said: "Indeed, our family was in the imperial superintendent in the early years, and saw that the tin in the Jingshi Palace had to add copper and lead when casting, and I don't understand why this is so, I think it must be to avoid the tin plague in winter with pure tin!" ”

Zhang Zixuan was still puzzled, she expected that Qin Lin must know the reason, so she only asked him: "With the weather in Yangzhou, the tin plague will not happen too quickly, how can it turn all 500,000 taels of silver into ash overnight?" ”

Qin Lin smiled but didn't answer, and asked Niu Dali to use wooden chopsticks to hold the tin block that he had just fried, stand under the tuyere, and asked Lu Fatzi to dissolve the red salt in the liquor and pour it on the tin.

After a while, I saw that the tin gradually turned gray, lost its metallic luster, and suddenly became shattered, and the ox could not hold it vigorously, and fell to the ground into a pile of ash powder.

Only then did everyone understand that the mixture of red salt and spirits could make the tin plague happen faster than usual!

Qin Lin smiled, the mixture of red salt and spirits was the catalyst for the tin plague!

Now the temperature is not as low as minus thirteen degrees Celsius when the tin plague occurs, but the volatilization of alcohol will take away the heat and reduce the temperature of the object below the temperature.

Back to the night when "Caoyin" disappeared, the temperature was extremely low, and the conditions for the tin plague were reached, Shi Jiangzong and his soldiers poured a catalyst mixed with alcohol and red salt on the tin ingots, and then sprinkled the ash powder turned into tin ingots into each box - so, it didn't take much work, all the tin ingots turned into ash powder, which could be easily discharged from the cave!

In this way, all the strange phenomena have a perfect explanation, someone in the cabin coughed because he accidentally inhaled the ash powder; The fish leaps over the dragon gate, which is the tin powder discharged into the river, the river water is polluted, the gills of the fish are blocked by the powder, and they jump out of the water in pain!

Why have no abnormalities been found in previous salvage attempts?

If it was tin ingots and silver ingots, they would have been scooped up a long time ago, but the tin ingots turned into dark gray powder, mixed with the silt at the bottom of the canal, who could see it? It's not that Qin Lin found the reason through reasoning and deliberately fished out the silt to fry and refine, or in another five hundred years, people won't find out that there is tin powder at the bottom of the river!

The case of the White Lotus Sect was almost seamless, but as Qin Lin said, there was never a perfect crime in this world, and the only flaw they left behind was hidden in the mud at the bottom of the river:

The density of gray tin is 5.75 grams per cubic centimeter, which is more than five times that of the river water, so the tin powder will not be washed away after being discharged into the water, but will be deposited in the silt at the bottom of the river.

(To be continued)