The Roman Empire once dominated for a while, but it flourished 100 years later, it went from bad to worse and finally went to extinction. Roman Empire

Where is the cause of extinction?

Some scholars pointed out that the decline of the Roman Empire was caused by lead poisoning. Later, when archaeologists excavated the tombs of the Romans, they found that their bones contained a lot of lead. This confirms the views of scholars. no

This is meaningless.

In ancient Rome, lead products, as a symbol of nobility and wealth, were deeply loved by people because they were soft and easy to add. Ancient Roman nobles generally used lead utensils, tableware and cosmetics, and especially liked to drink grape juice containing lead. At that time, when making amber grape juice, they always used lead pots or pots with lead on the inner wall to cook grapes, which took a long time. Until the juice is only one-third of the original. This kind of grape juice is especially sweet and not easy to rot, but the lead content is seriously exceeded. The extensive use of these lead-containing articles has caused many people to die of lead towel poisoning. At the same time, the water supply and drainage system based on lead pipes owned by the ancient Roman Empire also made civilians unable to escape the bad luck of lead poisoning.

However, people in ancient Rome knew nothing about all this.

The crowning touch of knowledge

Lead is a silvery white heavy metal with soft texture and low tensile strength.

When lead comes into contact with oxygen, water and carbon dioxide in the air, its surface will be oxidized rapidly, forming a dark gray protective film; After heating, lead can quickly combine with oxygen, sulfur and halogen; Lead has little effect on cold hydrochloric acid and cold sulfuric acid, but can react with hot or concentrated hydrochloric acid and sulfuric acid: lead reacts with dilute nitric acid, but does not react with concentrated nitric acid; Lead will slowly dissolve in strong alkali solution.

Related connection

Lead is a heavy metal element that seriously harms human health. It can affect many organs such as nerves, hematopoiesis, digestion, immunity and bones. What is more serious is that it affects the growth and intellectual development, neurobehavior, learning and memory of infants, and can seriously cause dementia.

When lead poisoning occurs, there will be symptoms such as constipation, abdominal cramps, lead thread and anemia.

In recent years, there have been 3 1 cow lead poisoning in China:

From July 2003 to 65438+ 10, 40 people in a storage battery factory in a district of Guangzhou suffered from occupational lead poisoning.

In 2004, hundreds of children were poisoned by lead in Changxing, Zhejiang, which is known as the "hometown of storage batteries".

In 2006, more than 300 children were poisoned by lead in Huixian County, Gansu Province.

Pure blue ink and blue-black ink

Open the homework written before, and find that some handwriting is vague, some handwriting is clear, and the words of the same period.

Trace, why is it so different?

After the festival, in order to welcome the New Year, every household began to clean, and Pingjia was no exception.

Mother asked Hu Ping to pack her things and put everything in order. When Pingping tidied up his homework book for the fifth grade of primary school, he opened it conveniently. "Ah, the handwriting is too vague, and it's not wet yet." Flat said to himself. Looking through another book, this one is very clear, which is even more strange. These were all written at that time. How can they be so different after a few days?

Just as he was wondering, his cousin came. Cousin told him: "This illegible handwriting is written in pure blue ink. It will be oxidized after a long time, and the color will gradually become lighter or even disappear completely; " This clarity is written in blue and black ink. After the blue-black ink is oxidized, it can gradually generate a chemical substance that will never fade-black iron tannic acid. Therefore, the handwriting is clear. "

Pingping picked up the exercise book and found that it was written with two kinds of pens. Pingping admired his cousin and was impressed by his erudition.