Chapter Fifty-Eight: The Value of Goods
Li Yuechen seized the opportunity to add some goat’s milk and aromatic oil. In this era, aromatic oils did exist, though they were known as fragrant dew rather than essential oils. According to Xiao He, they were not distilled but pressed, so their purity could not compare to the essential oils of the future. The only advantage was their being completely natural, free from chemical additives. After all, soap should carry a pleasant scent.
Speaking of fragrance, humanity has endlessly pursued delightful aromas throughout history—past, present, and future alike. Even when, a thousand years later, perfumes became the staple of daily life in this nation, incense remained the first thing people thought of when it came to fragrance. That is the power of culture: people savor not just the scent, but the poetic ambiance of curling smoke and pervasive aroma.
Shaking her head to clear her thoughts, Li Yuechen saw that the viscous liquid in the porcelain jar was nearly ready. She instructed the other eunuchs to don thick animal-skin gloves and carefully pour the mixture into the waiting molds.
Fulai, curious, stepped forward, immediately enveloped in a floral aroma. He bent down and asked, “Your Highness, what is this?”
“No questions—you’ll see once it’s finished,” Li Yuechen replied mysteriously, waving her hand and directing them to leave the molds in the sun for a few days.
Gazing at the irregular white blocks within the molds, Fulai tilted his head but followed Li Yuechen without further inquiry. She instructed the nearby palace maids to keep watch, then returned to the palace to study and practice calligraphy.
Shangguan Wan’er and her two sisters were present. Fulai lit a small sachet of incense and hung it before the desk. Wisps of smoke soon drifted through the hall, lingering above their heads.
Soon, Fulai brought a ledger. “Your Highness, these are the latest financial records from the shop.”
Li Yuechen acknowledged him, flipping through the pages while tracing figures on the tabletop.
The Princess of Xuancheng laughed, “No wonder Chen’er praised mathematics recently—was it all for bookkeeping?”
“Something like that,” Li Yuechen replied with a smile.
After about five minutes, Li Yuechen nodded and called Fulai over. “Good, your nephew has done well!”
“Thank you for your praise, Your Highness.” Fulai rose and departed with the ledger.
The Princess of Xuancheng seemed surprised. “I never imagined Chen’er could calculate so quickly—large sums counted in moments!”
Only someone unacquainted with higher mathematics would say such a thing; mere addition and subtraction hardly deserve the name of difficulty.
“This is hardly challenging—truly simple,” Li Yuechen replied breezily.
Her calm tone piqued the princess’s curiosity. “How did you calculate just now, Chen’er?”
Li Yuechen, with nothing better to do, decided to enlighten her. She wrote out Arabic numerals on the paper. “First, with these numbers, one can easily compose any sum…”
The Princess of Xuancheng was clever and quickly grasped the concept. Li Yuechen then explained the basics of addition, subtraction, multiplication, and division.
Princess Yiyang and Shangguan Wan’er listened with fascination.
“Multiplication is repeated addition, as in the multiplication rhyme: seven times seven is forty-nine. Conversely, division splits a number into groups, like forty-nine divided among seven groups, each group is seven…”
After explaining the concepts, Li Yuechen laid out a multiplication problem from the ledger and solved it.
“See? Very simple.” She set down the brush.
“Amazing!” The Princess of Xuancheng exclaimed, her eyes shining.
Princess Yiyang and Shangguan Wan’er widened their eyes, marveling at the wonders of mathematics.
The Princess of Xuancheng looked up. “Are there more examples?”
Li Yuechen nodded and began teaching her elementary mathematics problems.
Just days ago, the Princess of Xuancheng had dismissed mathematics as useless, but having witnessed its marvels herself, she was now completely engrossed.
Li Yuechen taught her for about an hour before planning to check on her soap.
The Princess of Xuancheng grabbed her arm. “Wait, just a little more…”
---
“I think it’s best if we do this,” Li Yuechen said, picking up some paper and writing, “Let’s see if you can apply what I’ve taught.”
She wrote out two problems: “A jar of preserves sells for five coins; buy five jars and get one free. If you buy forty-five jars, how much will it cost?” and “A bar of soap costs sixteen coins; buy three and get one free. With one hundred seventy-six coins, how many can you buy?”
She pushed the paper forward, tapping it with her finger and grinning. “Let’s see if you can solve these two problems.”
With that, she went to the courtyard to check on her soap, leaving Shangguan Wan’er and Princess Yiyang watching the Princess of Xuancheng ponder the questions.
Clearly, they were mentally working through the problems as well, though neither seemed as deeply absorbed as the Princess of Xuancheng.
She was lost in thought, scribbling calculations on the paper.
Li Yuechen found the soap had begun to set in the molds—pure white, even sparkling faintly in the sunlight.
She lifted the tray, leaned in, closed her eyes, and inhaled gently. A delicate floral scent rushed straight to her mind.
“Excellent…” Li Yuechen murmured, nodding.
Fulai still looked curious but asked nothing more.
Li Yuechen had them bring the tray inside and cover it lightly with a wooden board.
Back in the main hall, Princess Yiyang and Shangguan Wan’er had turned to other books, while the Princess of Xuancheng continued to wrestle with the two problems.
With what Li Yuechen had taught her, she could solve them, though her speed was slow—she had only just learned.
Three days passed in the blink of an eye.
Li Yuechen lifted the board covering the soap, found a cloth, and had two eunuchs flip the tray over, knocking the contents out.
With a soft clatter, a dozen bars of soap dropped onto the fabric.
Li Yuechen took two, handing them to Fulai and Xiao He. “Go wash your hands with these—here’s how you use them…”
After her explanation, they went to wash their hands.
She wrapped the remaining bars in the cloth and carried them into the main hall.
No sooner had she set them down than Fulai and Xiao He returned, faces full of astonishment.
Sitting cross-legged at the desk, Li Yuechen smiled enigmatically. “How was it?”
Fulai’s surprise was unabated. “Your Highness, this is truly miraculous!”
“Yes,” Xiao He agreed, “My hands still carry a lovely scent…”
She raised her hands to her face and inhaled deeply.
Li Yuechen only smiled. “Those two are yours now.”
Fulai and Xiao He exchanged glances and bowed respectfully. “Thank you for your generosity, Your Highness!”
Li Yuechen also gave a bar each to her two sisters, Shangguan Wan’er, and Lady Zheng.
This first batch was only a dozen bars—she had no intention of selling them yet, so it was best to let more people try them and see the results.
As for her parents, she would wait for further testing before presenting them.
Li Yuechen instructed, “Don’t let others know about this yet. I want to see how it works, and then I’ll present it to Father and Mother.”
They all agreed.
---
The next morning, as always, she practiced yoga with her sisters and Shangguan Wan’er.
Today was the day to check in at Liu Rengui’s house, so Li Yuechen rode a carriage to her mentor’s home for training.
Returning at noon, just as she sat down to eat, the Princess of Xuancheng rushed over, beaming, “Chen’er, look—I solved it!”
She handed over her paper.
Li Yuechen examined it—the solution was thorough, perhaps a bit wordy, but very well done.
She smiled and nodded. “Excellent, you truly have a talent for mathematics.”
“Do I?” The Princess of Xuancheng was puzzled. “I just found these problems interesting.”
“How about this afternoon, I teach you even more fascinating things?”
“Wonderful!” she replied eagerly.
---
For the next stretch of days, every afternoon, Li Yuechen taught her mathematics.
Time flew by, and before she knew it, October was ending.
The first batch of soap Li Yuechen distributed was nearly gone, and the results were clear.
Fulai and Xiao He had become ardent fans, now almost out but too shy to ask for more, pondering daily how to win another bar.
It was Princess Yiyang who finally mentioned that her soap was nearly finished and asked for another bar.
At her words, the others looked hopefully at Li Yuechen.
She gave each of them another bar, then took the remaining three to Anfu Hall.
Li Zhi had been in good spirits lately. Seeing Li Yuechen arrive, he called her over to chat.
Li Yuechen sat beside him at the low desk and grinned. “Father, I’ve invented something new again.”
“Oh?” Li Zhi’s interest was piqued. “Tell me about it.”
Without preamble, Li Yuechen handed him a bar of soap. “Father, please look—this is it.”
Li Zhi took it, examined it, and sniffed. “What is this? Is it fragrant balm?”
“No, Father—it’s for washing. Try washing your hands.”
Li Zhi nodded and called Zhang Chengxin to bring a basin of water. Following Li Yuechen’s instructions, he began to wash his hands.
Wu Zetian, curious, came over to see what it was.
Guided by Li Yuechen, Li Zhi’s hands soon foamed with white lather, which he rinsed away in the copper basin.
He dried his hands with a wool towel and scrutinized them. “Hmm… this feels unusual! And…”
He sniffed his hands. “Ah, there’s a floral scent.”
Wu Zetian had Zhang Chengxin change the water and tried it herself. She nodded in delight. “What a marvelous thing—it really does clean the hands well!”
Li Yuechen chuckled. “This soap can be used for washing hands or the body, just don’t let it touch your mouth or eyes!”
Li Zhi laughed heartily. “Excellent! As expected of my daughter!”
“I’m going to use this to earn money from the ministers, so you and Mother needn’t worry about finances anymore!” Li Yuechen declared.
Li Zhi nodded. “A fine idea!”
Wu Zetian said nothing further, but took a new bar and pondered.
Li Yuechen handed the last bar to Zhang Chengxin. “Eunuch Zhang, this is for you!”
“Thank you, Your Highness!” Zhang Chengxin bowed, delighted, and carefully received it.
Li Yuechen waved her hand, then turned to Li Zhi. “From now on, you and Mother will smell lovely every day!”
Li Zhi joyfully scooped her up, pressing his forehead to hers. “Ah, what a wonderful daughter!”
Li Yuechen laughed, playfully wrestling with him, while Zhang Chengxin discreetly bowed to Wu Zetian and slipped away.
After a while, Li Yuechen took her leave.
Only Li Zhi and Wu Zetian remained in Renshou Hall.
Li Zhi reclined in his chair, rolling his health balls again. “I never expected such a surprise from Chen’er!”
Wu Zetian picked up the new soap and smiled. “Once this hits the market, it’ll be incredibly profitable! When Chen’er spoke of opening a shop to solve Your Majesty’s financial woes, it seemed fanciful, but now it’s truly possible.”
Li Zhi nodded. “I always believed Chen’er was a prodigy—a blessing to our Great Tang. This invention may well make the noble families part with considerable sums.”
“Maybe we should advise Chen’er to set the price higher,” Wu Zetian mused, “so it won’t be easily resold.”
Li Zhi laughed. “You know me well, Meiniang! But I think Chen’er is already aware of this. Let’s observe for now.”
Wu Zetian nodded. “As you say, Your Majesty.”
They discussed pricing, while Li Yuechen was pondering the same problem.
From a cost perspective, selling each bar for twenty coins would still yield profit. But that was already unaffordable for ordinary people. Mass production could lower costs, but Li Yuechen also wanted to avoid others profiteering off her invention.
So… she needed to devise a way to maximize her own benefit.