The autumn seed Festival finally came to an end when the sun set in the West.

When Li Shimin and others returned to the Tai Chi palace, it was time to turn on the lights.

Several people after bathing and dressing.

Li Shimin recruited Li Chengqian, who was about to take the opportunity to sneak out.

Li Shimin watched Li Chengqian for a long time. When Li Chengqian was about to collapse, Li Shimin said faintly, "I know your thoughts and your character. Do you know why I let you learn from Zhang Feng?"

"My son knows!"

Li Shimin smiled and said, "tell me about it."

Li Chengqian doesn't know what Li Shimin is thinking. Since he met Zhang Feng, Li Shimin seldom talks to Li Chengqian.

After all, where doesn't Li Shimin know about Li Chengqian's fancy intestines?

Timid, suspicious, and more importantly, somewhat indecisive.

These can be seen from Li Chengqian when he was young.

Li Shimin also has his own plan to say it at this time.

Looking at Li Chengqian, Li Shimin patted the soft collapse around him and said, "it seems that our father and son haven't talked seriously for nearly a year?"

Hearing the speech, Li Chengqian hurriedly sat down beside Li Shimin.

But Li Shimin couldn't help sighing when he looked at Li Chengqian's actions.

"You did learn some skills during this time, but what I want you to learn most is Zhang Feng's self-confidence in coordinating all things and his way of dealing with things without surprise, but this year..."

"Oh! Tell me, what's the use of this mask and the phosphate fertilizer you stirred up?"

Li Shimin couldn't bear to say more after all.

After all, Li Chengqian's suspicions are more serious if he speaks too much. If he speaks too little, he is not good. Anyway, Li Shimin has a headache when he sees Li Chengqian.

No man is free and easy.

Finally, Li Shimin had to bypass the topic, but Li Chengqian didn't think so. He thought that his father was very dissatisfied with what he had done during this period and was worried.

Li Shimin patted Li Chengqian on the shoulder and said, "I'm very satisfied with what you've done during this time. I'll learn more from Zhang Feng's attitude towards life and his mentality, which is always good for you."

After talking with Li Chengqian for half a day, Li Shimin was also worried by Li Chengqian and lost his desire to talk.

He waved his hand and said, "what's the matter with this mask? What's the matter with this phosphate fertilizer? Can it be used in this autumn seed?"

Seeing Li Shimin changing the topic, Li Chengqian was also greatly relieved.

"Back to my father, this mask is the key to solve phosphorus poisoning. My son and others have been using this thing for a while, and the effect is very magical. Originally, my son intended to give it to my father when he got it last time, but on the way, I ran into doctor Zhou who came to diagnose my son's pulse."

"My son-in-law is going to give it to doctor Zhou first, so that he can use it in his daily diagnosis."

When Li Shimin heard the speech, he couldn't help brightening his eyes: "this method is indeed possible. What about later? I know that the cicada yarn is extremely rare. How did you deal with it?"

"Use white paper!"

When Li Chengqian saw that Li Shimin finally showed a rare smile, he didn't know that Li Shimin knew it just now. At this time, he told Zhang Feng about replacing the cicada yarn with multi-layer thin white paper.

Li Shimin couldn't help but stare.

"So, this mask is basically popular in Chang'an city now?"

Li Chengqian shook his head and said, "back to his father, this matter is not all popular, but for the time being, most doctors and doctors in Chang'an City have basically used it, and the children's ministers have also found some talented people from Bailu academy to teach these doctors the most basic physiological health knowledge. Even Taiyuan hospital has taken the physiological health knowledge as a course."

"Really?"

Li Shimin's eyes lit up.

He didn't expect to do this.

Li Chengqian nodded. "It's true, and as long as the doctor who has used it and learned about physiological health knowledge is basically used in daily diagnosis during this period, the effect is naturally very good."

"Moreover, the children's ministers have printed hundreds of books of the medical and health knowledge manual set up by Fengzi, and each book has basically been fried to the price of 100 Liang silver!"

Li Shimin's blood boils with enthusiasm.

This thing is really good.

He saw that thing and saw that Zhang Feng had used it on Niu Jianhu's leg. He also wanted to apply such a magical thing to the whole Tang Dynasty, but he didn't know how to speak, but he didn't expect the crown prince to step ahead of him.

This also seems to be a kind of progress?

Li Shimin nodded and said, "yes, I'm very happy to think of this step. Qian Er has made a lot of progress!"

"Tell me about the phosphate fertilizer!"

"Yes 1"

Li Chengqian had not been recognized by Li Shimin for a long time. At this time, seeing his father's praise, he couldn't help feeling a little elated. He was excited to tell the whole story.

Li Shimin didn't stretch his eyebrows.

After Li Chengqian finished, Li Shimin almost went to see Zhang Feng's masterpiece and that magical thing on the spot.

"I don't seem to have seen these new things for a long time!"

"Go up the mountain with me tomorrow!"

Hearing this, Li Chengqian hurriedly said, "father Huang, Fengzi is at Chang'an University at this time."

"Hahaha, do you think Fengzi is so easy to fool? Believe it or not, this boy must be on the mountain now!"

“……”