Seeking Truth with a Sword

Chao Gai and Abe Takano spoke earnestly and in great detail about the symptoms afflicting their compatriots back in Japan.

Initially, patients would experience weakness in their lower limbs and a general lack of strength, followed by appetite loss, nausea, and vomiting, and then swelling and ulceration of both feet. In severe cases, they would be unable to walk normally or even get out of bed, eventually becoming paralyzed and lying in bed awaiting death.

"I see..."

Li Ang leaned back slightly, observing the two individuals who had just paid him great homage, and fell into contemplation.

Abe Takano spoke in a softened voice, "I heard Mr. Li enjoys admiring gold and silver tableware. Our home, Japan, produces an abundance of gold and silver. The people from my hometown specifically instructed me to bring more of our local specialties..."

"That can be discussed."

Li Ang gave a wry chuckle and waved his hand dismissively.

So the news of his liking for gold and silver luxuries had spread overseas? Did it really have to be this exaggerated?

"Hmm... There are quite a few potential diseases that could cause these symptoms. Without seeing the actual patients, it's difficult for me to make a direct judgment."

Li Ang thought for a moment and said, "I remember that the Envoys to Tang typically bring many people with them, don't they? I wonder if you know any patients here in Chang'an?"

"We do know one."

Chao Gai immediately replied, "He is a merchant living near the West Market. Should we ask him to come over?"

"Oh? If he's ill, perhaps it would be better for us to go to him."

"No, no, no, how could we trouble Mr. Li?"

Chao Gai quickly stood up, went to the courtyard gate, and spoke a few words to the servants waiting there. The servants immediately ran towards the West Market, and shortly thereafter, a carriage entered Capital City Square.

Two servants helped a Japanese man down from the carriage. Indeed, just as Chao Gai and Abe Takano had described, his feet were slightly swollen.

Li Ang examined him briefly, then suddenly asked, "Have you had dinner?"

"Ah?"

The Japanese merchant, aware of the noble status of Chao Gai and Abe Takano, was especially apprehensive and, facing Li Ang, found himself at a loss for words.

The Abe family's ancestors descended from Prince Da Yanming, son of Emperor Xiao Yuan, and their lineage had produced many high officials, making them exceedingly noble in Japan. For them to be so respectful... Li Ang's status was clearly even more distinguished.

Seeing the merchant stunned, Chao Gai couldn't help but say in a low voice, "Answer Mr. Li."

"Oh, oh, yes, I've eaten. At the Ping'an Restaurant in the West Market. I had kui cai, roasted fish, and tofu soup."

"What about rice?"

The merchant replied, "I ate a bowl of polished rice."

Polished rice is finely milled white rice, which is whiter, has a better texture, and is, of course, more expensive.

"Mm-hmm."

Li Ang nodded, as expected. "It looks a bit like a vitamin deficiency..."

"Vitamins..."

Chao Gai cautiously asked, "Is it the same illness that the National Guardian General had before?"

As an official in Chang'an, he had learned a few things about Li Ang through casual conversations with colleagues, including the successful treatment of Yan Yundang.

"Something like that. But it's not the same vitamin," Li Ang said casually.

Yan Yundang suffered from anemia, caused by a deficiency in vitamin B12. In contrast, this Japanese merchant most likely has beriberi, caused by a deficiency in vitamin B1, or thiamine. Thiamine is a vitamin synthesized by fungi, microorganisms, and plants; animals and humans cannot produce it internally and must obtain it from external sources. A deficiency disrupts sugar metabolism and impedes sugar oxidation, leading to an accumulation of pyruvic and lactic acid. This affects the body's energy supply, and clinically, symptoms manifest in the digestive and circulatory systems—in other words, beriberi.

Li Ang asked, "If I'm not mistaken, Japanese nobles are quite fond of eating polished rice, correct?"

"Yes," Abe Takano nodded respectfully. "Ever since the Upper Country bestowed new-style waterwheels upon us two hundred years ago, it has become popular in Japan to use waterwheel mills to finely grind rice."

"And what about meat?" Li Ang asked. "Do you normally eat the meat of animals like chickens, ducks, cattle, sheep, and pigs?"

"Well... we eat a little, occasionally."

Chao Gai and Abe Takano exchanged glances, then awkwardly began to explain. During the Pre-Sui Period, Japan was already a vassal state of the Sui Country. At that time, the Regent Prince Shengde, seeking to counter the political interference of an influential maternal clan, the Suwo Clan, drew inspiration from Hui Ci, a high monk from Korea. He resolved to emulate the Sui system by consolidating monarchical power, promoting Buddhism, and unifying thought. Prince Shengde boldly implemented a series of sweeping reforms. These included, but were not limited to, establishing a twelve-rank cap and attire system to differentiate official ranks by the color of hats and clothes, appointing officials based on talent rather than heredity, and promulgating a codified legal system. During this process, the self-assured Regent Prince Shengde also shifted Japan's previously submissive stance towards the Sui Dynasty. He had his envoy, Xiao Ye Mei Zi (whose name, despite 'Meizi' meaning 'girl,' referred to a man), deliver a state letter to the Emperor of Sui. This was the very famous missive: "From the Emperor in the land where the sun rises to the Emperor in the land where the sun sets, I respectfully inquire after your well-being."

Of course, having confidence is one thing; putting it into practice is quite another.

Prince Shengde's reforms ultimately failed due to obstruction from the maternal clan, and he himself died in regret under their surveillance and oppression. Only his fervent devotion to Buddhism persisted. As Buddhism prohibits meat consumption, Prince Shengde enacted a ban on meat, using harsh laws to restrict people from eating the meat of cattle, horses, and chickens. Later, this ban was extended to include pork and dog meat.

Vitamin B1 is primarily found in the outer husks and germs of seeds, like rice bran and wheat bran, and also in the meat of poultry and livestock. It was hardly surprising, then, that Japanese nobles, who consumed neither brown rice nor much meat, would suffer from a vitamin B1 deficiency.

"Mr. Li, this illness... can it be treated?" Chao Gai cautiously asked.

"It can. I just need to prepare a few things. Please wait here for a moment."

Li Ang thought for a moment, then went to the backyard to find the hand-cranked centrifuge he had used before. He also found some yeast from the kitchen, the kind used for making steamed buns.

Using the method for extracting vitamin B12, he filtered, centrifuged, and purified the fermented yeast liquid.

He poured the supernatant from the test tube and, returning to the living room, handed it to the Japanese merchant.

"Here, drink this. If all goes well, you should see results within seven to ten days," Li Ang said.

Yeast contains a large amount of vitamin B1. Drinking the purified liquid can completely replenish the deficiency. Afterward, as long as he eats more meat, whole grains, and brown rice, the condition should resolve on its own.

"Yes, yes."

The Japanese merchant nodded vigorously, respectfully took the test tube, downed the solution in one go, and even smacked his lips afterward.

"I am truly grateful to you, Mr. Li."

Abe Takano bowed deeply to Li Ang once again, his voice filled with excitement, "This means my mother can be saved!"

Chao Gai also said, "Mr. Li, this is your consultation fee. Please wait a moment, I'll go to my residence and bring back more gifts..."

"No need, no need. Treating the sick and saving lives is what I ought to do."

Li Ang paused. "As for remuneration, Takano, could you let me see those prayer beads you're holding?"

In his perception, the translucent prayer beads in Abe Takano's hand were emitting a subtle fluctuation.

A familiar fluctuation—the kind characteristic of a Sword Immortal's relic.