ask sword 2

Chapter 54 Variables
Li Ang raised his brows in surprise, Song Shaoyuan and others also frowned, looking in the direction of the voice in dissatisfaction.

In the box next to the restaurant, Qiu Jian, a medical officer of the Imperial Medical Office with a badge of the Taiji Palace hanging on his waist, looked at his friend who was dressed as a scholar in blue clothes and had a sullen face across the table, and couldn't help shaking his head and smiling bitterly.

It's no wonder that the middle-aged man sitting opposite Qiu Jian will be displeased. On the table between the two is a large-scale map of Chang'an city, which depicts the square city, canals, wells, etc. in detail. Views of farmland, streets, bridges and even the Royal Palace.

Chang'an map, or map,

Ordinary citizens are not qualified to hide or even contact them, because there will be suspicion of intentional treason.

However, the Confucian scholar in Qingyi had no such concerns at all—his name was Tantai Leshan, and he was one of the Doctor Si Ye who taught Talismans and Engineering in the Academy.

This map is a renovation drawing designed by Tantai Leshan and its students for Chang'an City at the invitation of the Ministry of Industry and Commerce of the Ministry of Commerce.

"Brother Leshan"

Qiu Jian coughed lightly. He knew very well how much effort Tantai Leshan had put into the renovation of Chang'an City during this period.

Transportation, housing, drinking water, transportation, and city defense for 300 million people. In order to facilitate the people in the city to the greatest extent, Tantai Leshan and his students inspected every corner of Chang'an City, repeatedly discussing, deliberating, experimenting, and improving all issues.
This map is the brainchild of Tantai Leshan over the past year. It is hard to bear the groundless criticism of others.

What's more, he also mentioned the canal system that he is most proud of and will cover all parts of Chang'an in the future.

However, the people sitting next to them were obviously the students who came from other places this year and were preparing to take the exams at the academy.

The two of them, one is the medical officer of the Imperial Physician's Office, and the other is the school secretary, and they accidentally overheard the conversation between the students next to them.

"Ah."

Tantai Leshan nodded and gestured with his eyes to the servant standing in the corner. The latter immediately understood, walked out of the door quietly, came to the next door, and knocked on the door to apologize.

"I'm really sorry to disturb the gentlemen's banquet,"

The servant cupped his hands and said, "It's just that my master simply wants to know, why do you say that the more drains you repair, the easier it is to breed diseases?"

"Ah, it's nothing, we're just talking and playing, sorry for disturbing the next door."

Yang Yu was keenly aware of the coming of trouble, he laughed and hit haha, he just wanted to fool the past,

However, the servant's ears moved, and he continued to say gently: "My master said that the way of academic study for the disciples of the school is to respect the rules of heaven and earth, make bold assumptions, and prudently prove. There is no absolute truth and authority, or truth and authority are based on To constantly question and verify. If you feel that something is unreasonable, you can directly point it out and discuss it rationally.”

Yang Yu's eyelids jumped,
There are many big families in Chang'an City, but not any family can have such servants who can talk and talk casually, which is the purpose of the academic palace.

Whoever sits next door is trouble.

For a while, no one in the box spoke, and the scene suddenly became cold, only the sound of Chai Cuiqiao chewing ribs.

crunch.

Perhaps the sound of Chai Cuiqiao chewing the bones was too loud. Ji Linglang and others looked at Chai Cuiqiao subconsciously, which made her gradually realize that the surrounding atmosphere was not right, so she nervously chewed the bones and lowered it slightly. Click volume.

crunch.

Shameful. Shameful.

"Well, that was what I said just now."

Li Ang put the chopsticks on the bowl and said casually: "The Yellow Emperor's Classic of Internal Medicine, Plain Questions, The Great Theory of Yin and Yang Yingxiang" says: The center generates dampness, dampness generates soil, soil generates sweetness, liver generates spleen, spleen generates meat, meat generates lung, spleen generates Main mouth. Thought hurts the spleen, anger overcomes thoughts, dampness hurts the flesh, wind overcomes dampness, sweetness hurts the flesh, and sour overcomes sweetness.

Since ancient times, the people of the Central Plains have been afraid of the humble and wet, and of the damp and cold environment, so they all hope to live as high as possible.

Therefore, the land price in the north of Chang'an, which is higher in terrain, is higher than that in the south of the city.

This phenomenon of citizens' instinctive fear of low, wet and low-lying is actually the result of long-term accumulation of experience - living in a high place means that people who live in a low place are less likely to get sick.

Everyone should understand this, right? "

"Ah."

Before the others spoke, Yang Yu nodded.

It is no secret that the land price in the north of Chang'an is higher.In fact, the former Sui Dynasty built the palace on the high ground in the north of the city, in order to keep it away from the wet.

In the book "On the Origin and Symptoms of Diseases, Volume [-], Wind Bi" compiled by the former Sui physician Chao Yuanfang and others, it is bluntly stated that the causes of wind bi include wind, dampness and cold.

In the past, the construction standard of the Sui Palace could avoid the two factors of wind and cold, and in order to avoid humidity, it was necessary to live in a cool place.

"Low-lying, low-humidity, and disease, these three words have been bound together for a long time.

But if you think that low-lying, low-lying humidity is the direct cause of the disease,

That is tantamount to arresting the blood-stained Pu Dao at the murder scene as the murderer. "

Li Ang said casually: "Low-lying, low-lying and humid are the indirect causes of illness.

The direct cause is water and grass.

To be more precise, it is a mosquito that attaches to aquatic plants. "

"mosquito?"

Everyone, including the servant, looked surprised. It is widely believed in the folk and medical circles that the reason why people get sick is largely because of external evils entering the body.

Exogenous evils, that is, external things that can harm people's body and mind, are nothing more than wind, cold, dampness, dryness, fire, and epidemic qi, etc., excluding mosquitoes.

"Yes."

Li Ang nodded and said: "In the 22nd year of Jian'an, the plague was prevalent. Every family felt the pain of zombies, and every room was crying. Some died after closing their doors, or lost their families.

This terrible epidemic is malaria.

cause of malaria.
I happened to hear my father talk about a medical case where there were twin brothers and twin sisters in a certain place.The two couples live next to each other, live in the same lane, work in the same place, and eat the same food every day.

In the fall, however, one couple died of malaria, while the other survived.

If it is said that malaria is caused by exogenous pathogens, then why is another couple with such a similar constitution and basically the same living environment, okay?

After careful investigation, the only difference between the two couples,

The family with malaria kept a water tank in the yard, and usually drew water from the tank.

Another household fetches water from the river every day.

However, the water in the tank is also drawn from the river.
Then there is only one difference between the two.

That is, the larvae mosquitoes that are attached to the water tank.

When all the factors of the two scenarios are the same, only one factor is different, and the results of the scenarios are different,

The only thing that makes a difference, then, is the variable that determines the effect.

That is, the control variable. "

(End of this chapter)