"How much saltpeter was used to make this ice?"
"Only five taels. The saltpeter can be retrieved from the ice and reused next time," Li Jingyun said, then she wanted to run out and bring in the large bowl to prove her words.
Indeed, saltpeter can be reused. After making ice, the ice containing saltpeter can be taken out. Through distillation or natural evaporation, it will turn back into saltpeter.
Li Shimin didn't stint his praise. "Little Hong Xuanni is so smart. You learn everything quickly. Since that's the case, go to Hongwen Academy to study with your elder brothers and sisters."
"Ah? Do I have to get up early?"
"Of course."
The little girl puffed up her cheeks angrily, looking like a steamed bun, which made Li Shimin burst into laughter.
Li Mingda also laughed. Her younger sister was always lazy. It would probably take her some time to get used to getting up early every day for school.
"Your Majesty! The Empress is unwell! She fainted!"
The laughter in the palace hall suddenly stopped. Li Shimin reacted first and rushed over in a hurry. Changsun Wuji followed closely behind.
Along the way, Li Jingyun tightly held her sister's hand, and their palms were both sweating. They were too young to understand life and death. They only knew that if someone died, they would never see that person again.
Never see their mother who loved them so much again? Just thinking about it made Li Jingyun feel as if the sky was about to collapse.
All the concubines, princes, and princesses in the harem, whether legitimate or not, came. A large crowd gathered in Lizheng Hall. Everyone looked worried.
Hearing their whispered discussions, it seemed that Empress Zhangsun's condition was extremely critical this time. She had even vomited a large amount of fresh blood, and the imperial physicians in the Imperial Medical Bureau were at their wits' end.
"Father just gave the order. The imperial physicians are still prescribing medicine and diagnosing the pulse. Don't go in and disturb Mother," seeing that Li Jingyun and Li Mingda were eager to go in, Crown Prince Li Chengqian grabbed his two little sisters, one in each hand.
The future magnificent crown prince was now just a young boy in his early teens. He was dressed in a moon - white round - collared robe, standing upright and looking handsome. But now he was obviously worried and uneasy.
Li Mingda said worriedly, "Mother was fine a few days ago?"
"Mother was tired after looking at the accounts of the harem today, so this happened," Li Chengqian said helplessly.
Raising the princes and princesses and managing the harem were all within the Empress's duties. Because he felt sorry for the Empress and was worried about her health, the two newly born daughters didn't grow up by her side. If she couldn't even see the account books, then the Empress would seem derelict in her duty.
Hearing this, Li Jingyun frowned and puffed up her cheeks like a steamed bun. She imitated an adult and sighed deeply. Then she sat on the steps in front of Lizheng Hall with her chin in her hands, watching the imperial physicians with medicine boxes frowning and walking by in a hurry.
Even two palace servants passing by outside were sighing. A kind and benevolent person like Empress Zhangsun was now in such a difficult situation. It was really a pity that good people didn't live long. They wondered when the so - called famous doctor Sun Simiao would enter the palace to treat the Empress.
Li Jingyun didn't quite understand those long - winded words, but she caught a key point: Sun Simiao!
Li Chengqian was worried about his sister and followed her. His sister asked him, "Brother Crown Prince, do you know where Sun Simiao is now? Why can't he enter the palace to treat Mother?"
"He became a Taoist priest early on and didn't like to associate with the royal family. When Father first ascended the throne, he was summoned to be a doctor of the National Academy and promised high - ranking official positions and generous salaries, but he refused. He has been practicing Taoism in the Bashu area and is said to have made great achievements. Now that the heavy rain has just stopped and the roads have been damaged, he is trapped in Shangzhou. It's a pity that Shangzhou is only a few days' journey from Chang'an."
Li Jingyun's mind was working rapidly. She seemed to remember that there was a method of road construction in an ancient book she had.
A book appeared in her mind, and the pages were flipping crazily. She finally found the secret method: the manufacturing process of cement. Cement was a powder after processing. When mixed with water, it could stick sand and stones together!
It was a great thing! An absolutely great thing!
"I know a kind of cement that can make the road surface smooth and it won't deform for a hundred years. If we pave the road well, Taoist Priest Sun can come," Li Jingyun pulled her elder brothers and sisters together, formed a small circle, and whispered.
"What is cement? Is it easy to make?"
"Don't tell me it will take a long time? Mother's body can't wait!"
"What do we need to do? Donate some money?"
The others surrounded Li Jingyun and asked questions one after another.
The noise made Li Jingyun's head buzz. She scratched her head, twisted her fingers, and looked at Li Chengqian worriedly. Li Chengqian understood what she meant and shook his head helplessly. "I'll provide the raw materials. No matter how expensive they are, I can find them. But we need Father's order to mobilize the craftsmen."
"Silence!"
Wang De, who served beside Li Shimin, came out and shouted.
At his shout, everyone fell silent, including Li Jingyun.
"His Majesty has an order. Everyone is to enter and pay their respects."
"Come on. Hurry in."
The two sisters followed their two elder brothers and finally entered Empress Zhangsun's bedroom. Several imperial physicians looked ashen - faced, their legs trembling. They were standing shakily beside the bed. On the bed lay a graceful woman with a beautiful but extremely pale face. Li Shimin was guarding the bedside, tightly holding Empress Zhangsun's hand.
Li Shimin had given an order not to let anyone in to disturb, but he turned a blind eye to the two little heads that were approaching and let them in.
"Mother!" Li Mingda called softly, which brought Li Jingyun back to her senses.
"Come here and let me take a look. Why do you seem to have grown so much in just a few days?" Empress Zhangsun waved her hand weakly, asking the two little daughters to come closer.
Before her delivery, the imperial physicians had said that she was old and it would be difficult for her to give birth. These twin daughters were born at the cost of her life. How could she not love them?
Empress Zhangsun leaned against the soft pillow, holding one daughter in each hand, with all her heart and eyes full of love. She also felt regretful that she wouldn't be able to see her two daughters grow up, come of age, and get married.
Li Jingyun held her mother's slightly cold hand and heard the imperial physician say, "Your Majesty's body is weak. We are not skilled enough in medicine and are unable to save her."
Tears welled up in her eyes. Finally, she couldn't hold it back and burst into tears.
"Don't cry, Hong Xuan. Don't cry. Mother is still fine," Li Mingda instinctively hugged her sister. Her voice was obviously crying, but she was still comforting her sister.
Empress Zhangsun's eyes were also red, as was Li Shimin's. If it weren't for the two daughters being there, he would have hugged his Guanyinbi and cried bitterly.
The whole Lizheng Hall was filled with a gloomy and depressing atmosphere.
Everyone surrounded Empress Zhangsun and whispered. They didn't even dare to breathe loudly.
Li Jingyun stood in front of Empress Zhangsun, biting her lips and looking at her pale face. Her chubby little hands were tightly clenched. She didn't want to part with her mother. She would never let her mother die!