The old things I repaired have become fine

Chapter 658 The secret recipe passed down through generations of single-lineage practitioners is unacceptable! It will be lost forever!!!
Shen Le stared at the crooked and messy handwriting in front of him, and in an instant, he was transported back to the "Compendium of Materia Medica".

Lead, also known as lapis lazuli, black tin, gold, and gold in water.

Red lead, also known as yellow lead, red powder, cinnabar powder, and lead enamel.

—Could you please provide an accurate name?
Is one name and one object acceptable?!
Sigh, modern chemistry is so much better. Every mineral has a scientific name; at the very least, even if you don't know the scientific name, you know its molecular formula.

For example, a whole bunch of names like "chalky ash, slag ash, stone chalk, five flavors, dye ash, loose ash, white ash, flavor ash, forged stone, stone forging, mineral ash, white tiger" can make your head spin.

However, regardless of whether you know its scientific name or not, as long as you can determine its molecular formula as CaCO3, you can confirm:
This stuff is calcium carbonate!

Taking the elderly to the market to shop can solve some problems, but it can't solve all of them.
"Water jade? This is water jade, this is water jade, and this is also water jade. I don't know which kind the master and the others are using..."

"Stone? The master never buys stone; he always quarries it from the mountains!"

"The white stone resin is supplied by a distant cousin of the master, who lives near Mount Tai and sends it twice a year..."

"The moonstones were ordered from the caravan, which came once a year to deliver enough for the year's needs, and the kiln kept three years' worth of stock... Where did the goods come from? We don't know, we only know that the caravan came from Guanzhong..."

Shen Le: "..."

Can I go and die?

May I?
Could I just die and leave this memory, then return to reality, diligently research the materials, consult classics and papers, understand the formula for Xing kiln translucent white porcelain, and then come back here to fire porcelain?!
Unfortunately, that didn't work. Shen Le could only rack his brains, recalling that when he was restoring the scroll, he had at least fought against those ancient mineral pigments, and remembered seventeen or eighteen of their alternative names...

"Logically speaking, the general formula for white porcelain glaze should include limestone, feldspar, kaolin, quartz, and the like."

There may also be some ingredients in lower concentrations, such as talc, titanium dioxide, and wood ash…

fall!
How do you even tell which of these things is which?!

Shen Le was dizzy and disoriented, so he could only drag his family members from his hometown over mountains and valleys, searching for quarries and mines one by one, asking them about everything.

After much effort, I finally figured out that "square stones" are those translucent, small, square stones in various colors such as light yellow, light red, and brownish-black.

"But the stones that the master and his men brought back were almost colorless. A few years ago, they found a batch that was as white as ice and as jade, and the glaze produced from them was exceptionally good..."

Great, case solved! This stuff is calcite, chemically known as CaCO3.

Colored glazes are mostly mixed with other impurities, such as iron or manganese, and the color of the glaze after firing will definitely be wrong.

As for the ice-like and jade-like material, Shen Le couldn't help but think of a famous name: Iceland spar... It's mainly used in the defense industry and the manufacture of high-precision optical instruments. Using it for porcelain making would truly be a waste of its resources...

Since it has been determined that calcium carbonate accounts for about 40%, it can be inferred that the water jade, which accounts for about 20%, is probably, perhaps, or possibly quartz.

When Shen Le selected an almost crystal-clear, colorless quartz stone at the market according to this standard, the old folks held it in their hands, examining it from left to right and right to left, before hesitatingly answering:

"It might be it..."

Next, the white stone powder stumped Shen Le. According to the old man's description, it was "near Mount Tai," but surely that couldn't be stone ginseng powder?
As the name suggests, it is a very white, very fine stone powder with a soft, creamy texture – stone mud.

Shen Le racked his brains for a long time, but couldn't recall anything about ancient mineral pigments. However, he did find relevant information in the Compendium of Materia Medica:

"White stone grease is the same as five-colored stone grease... It astringes lung qi and astringes the large intestine..."

It treats diarrhea, dysentery, metrorrhagia, leukorrhea, hematemesis, epistaxis, and also astringes semen and promotes urination; it calms the mind and soothes the five internal organs; it relieves restlessness and treats palpitations; it drains pus and treats boils, hemorrhoids, and fistulas; it nourishes the spleen, strengthens muscles and bones, and replenishes deficiencies…”

So what exactly is this thing?!

Why can a certain mineral astringe lung qi, astringe the large intestine, and treat diarrhea, dysentery, metrorrhagia, and leukorrhea...?

What mineral could possibly have such miraculous effects? Surely it's not like you just grind up a piece of spirit jade and mindlessly add it to the medicinal soup, is it?!

Shen Le gritted his teeth, decided to wear the wooden plaque given to him by the "Immortal Master," dressed smartly, and went into the city to visit medical clinics. After consulting with five or six doctors and summarizing their experiences, he received a consistent answer:

As for functions like treating hemorrhage, vomiting blood, relieving anxiety and palpitations, draining pus and treating boils, hemorrhoids, etc., just take these with a grain of salt and don't pay too much attention to them.

However, the fact that it "astringes the large intestine" has been verified by physicians. When diarrhea persists, adding white ochre to the medicinal decoction has a very good astringent and antidiarrheal effect...

"Then... could you sell me some white stone powder?"

Shen Le pleaded earnestly. The old doctor stroked his beard, shaking his head rapidly:
"I'm sorry, young friend. In these times, trade routes are often disrupted, and the little medicine we have in the pharmacy is reserved for major disasters and epidemics."

Besides, the white stone resin stored in the pharmacy is used to save lives; you're taking it to make glaze for porcelain. How can trivial matters, like those of other crafts, compare to medicine?

Shen Le: "..."

Shen Le really couldn't refute it. He nodded repeatedly, pretending to be learning, while trying hard to think about what this "white stone paste" actually was:

Minerals, astringent, and an effective remedy for diarrhea. Doesn't that sound a bit like montmorillonite powder?
If you get an upset stomach, taking a packet of montmorillonite powder will usually stop the diarrhea immediately. Its mechanism of action is to adsorb bacteria and viruses in the intestines, as well as the toxins they produce.

The main component of montmorillonite powder is actually kaolin, a white, fine-grained kaolin with tiny crystal particles...

It feels a bit like being driven to desperation and eating clay! Disaster victims, starving people, and refugees have nothing to eat, and food hygiene is completely unreliable. It's highly likely that dysentery will spread among the refugees.

At this time, a dose of kaolin clay could cure half of these dysentery and diarrhea ailments, giving the disaster victims a second chance and allowing them to hold on for another day or two...

Thinking about this, Shen Le didn't know whether to laugh or cry. If after going through all that trouble, he finally determined that part of the glaze was kaolin, why bother venturing into the medical field at all?
Among porcelain clays, kaolin is the most famous!
He respectfully bid farewell to the old doctor and rushed to the mining area, where he rummaged through the warehouse and found a bag of kaolin.

As for the moonstone, Shen Le looked it over from left to right and guessed it was something else he had seen before:
Borax!

He wasn't entirely clear on the wide range of uses this stuff had in porcelain firing. However, when he was repairing Li Xingtang's work, he had long admired borax's reputation in gilding, silvering, and welding.

This stuff is a universal flux!

It can remove the oxide layer on the metal surface and lower the melting point of the solder. Basically, you can't do without it when you're soldering gold or silver jewelry!
Most importantly, it has several other names, including "Dapengsha, Pengsha, Pengsha, Yueshi, and Pensha"—see, it even has the name "Yueshi"!
With a direction, it was easier to find the materials. Shen Le visited several shops that made gold and silver jewelry and copper and tin products, and collected enough borax. Following the glaze mixing methods he had learned in modern times, he crushed and ground all the calcite, colorless quartz, and borax into a paste-like consistency, and mixed it with kaolin to make a glaze.

Oh, and there's one last item on the glaze formula sheet:
The secret glaze material weighs one tael and six mace...

What is the secret glaze?
Tell me what it is!

Don't just write "secret glaze"!!!

Shen Le stared intently at the small booklet, its edges tattered but its pages perfectly preserved, as if he wanted to stare a hole through it so that the formula for the "secret glaze" would automatically appear.

No matter how much I stared at it, how much I held it up to the sunlight, how much I carefully heated it over a candle, or how much I tried to wet it, I couldn't force it to show even a trace of writing.

When I asked the people in my hometown again, the answer I got was:

"This is a secret recipe! The Lu family's secret recipe! The secret recipe for translucent white porcelain, passed down to only one person per generation. When preparing the glaze, the master personally handles it, kicking everyone else out and mixing the glaze inside..."

Shen Le: "..."

Alright, so-called "passing down to sons but not daughters", "passing down to sons but not daughters-in-law", "only passing on to one person per generation", and "masters only passing on their teachings to their disciples when they are on their deathbed".

The results were all exactly the same; one wrong move and the dating would be completely wrong...

"By the way, young master! The things the master passed down to you! The things he gave you at the end, they should be in there!"

Shen Le rushed into the room, crawled under the bed, pulled out a brick from the foot of the bed, and felt a small package inside the brick hole. She opened it layer by layer, staring blankly at the fine, grayish-white powder inside:
So what exactly is this thing?

Can someone tell me?
I need a chemistry lab, an X-ray spectrometer, all sorts of instruments and equipment. Help me identify what this thing is...

Otherwise, am I supposed to look with my eyes, touch with my hands, and taste with my tongue?!

Shen Le ultimately decided that he would not bother with the secret glaze for the time being until he could figure out how to fire a complete piece of porcelain.

He focused intently on applying the glaze, which was missing about 1% of the secret glaze formula, to the porcelain blank before sending it to the kiln to fire.

Then, it began to struggle through failure after failure, getting up and falling down, falling down and getting up again:
"Why didn't this batch fire up!"

“Well… young master, your saggars are arranged too close together… too tight in the front and too loose in the back, it’s exhausting for the kiln workers. The row of saggars in front of you is too close together, the fire can’t get through, no matter how you fire them, they won’t turn out well!”

Shen Le wiped away sweat. In modern times, when he was setting up the mortar and pestle according to the master's instructions, he only knew how to do what the master said. It was a relay race between several students, who completed the task with laughter and joking.

The master didn't reveal the tricks of the trade; after all, it wouldn't be useful for the students anyway, and they wouldn't remember them. Even if they went to work in a porcelain-making workshop later, they'd have experienced masters to teach them step-by-step…

"Sigh, if only I had studied properly with my master back then." Shen Le sighed, then rallied her spirits:

"Wait! Why did this whole batch collapse? It wasn't even fired long enough, how did it all fall over and smash to pieces!"

"That... the back is tight and the front is loose, as fast as thunder... if the back is too dense and the front is too sparse, the fire will leap over too quickly and go out soon, and the saggars inside will fall over..."

Shen Le could figure this out. The gaps in the first few saggars were too large, so the flames couldn't stay inside the kiln and were quickly vented out by the chimneys, causing the flames to flow too fast.

In that case, the fire would be extinguished after a dozen or so hours. The sagger, burned halfway through, would not be able to withstand the force of the high-temperature airflow and constant pushing, causing it to collapse and resulting in heavy losses.

But when I was setting up the saggars by hand, it was really just a tiny bit off!
I don't see much difference...

Shen Le inwardly groaned as he rolled up his sleeves and studied diligently. Alas, for an ordinary kiln worker, it takes decades of study to gradually rise through the ranks.

From the lowest ranks of the craftsmen (one and a half, two and a half, three and a half), one can progress to the highest ranks, such as the potter's wheel, the table-setting master, and even the stake-holding master.

During this process, being scolded and whipped by the master was commonplace.

A newcomer to the profession, seeing the prestige of the master craftsman and the exquisite porcelain coming out of the kiln, while thinking about the high salary and respect, inevitably also thinks:

"How many beatings would he get?!"

Unfortunately, no matter how much you are beaten, some positions are inherently reserved for certain surnames, and people with different surnames can never rise to those positions, no matter how hard they try.

Just like the master craftsmen at the Lu family porcelain kiln, and even the skilled craftsmen at the lower levels, their skills have been passed down through generations within the Lu family, even to the head of the Lu family. No matter how well an outsider performs, it's useless; they won't give you the opportunity to learn.

For someone like Shen Le, or the young master of the Lu family, even if the porcelain kiln is destroyed and the family is scattered, the old servant's training method for him was from the very beginning to aim for him to become a master craftsman.

To this end, they spared no expense, watching him burn one kiln after another, using such an extravagant method to ensure he memorized every technical detail...

Make saggars, arrange saggars, seal the kiln door, select pine firewood, light the fire and watch the fire.

Shen Le couldn't remember how long he had been working on it, only that from fleeing in the dead of night to firing the first batch of finished products, the mountains were covered in snow, and then spring had arrived:

"I finally succeeded in burning it..."

He held up the small porcelain cup to examine it closely in the light. The cup was as thin as an eggshell, its inner and outer walls covered in a smooth, lustrous glaze. Under the bright sunlight, it seemed to glow faintly.
"No, it's not done yet." The old man struggled to sit up halfway in bed, looked up at the porcelain cup, his eyes shining with an unusually bright light, but he still shook his head with difficulty.

“The glaze…the glaze is different…Lu family projection white porcelain…transparent white porcelain…”

He couldn't say anything more. A devastating tragedy had struck; the kiln was destroyed, the entire clan wiped out, and his family perished in that catastrophe. He escaped with Shen Le, dedicating a year to teaching her with all his heart—

A cold lingered from winter to spring and never fully healed; now I can't even get out of bed.

He took a few deep breaths, a chilling "whoosh" sound emanating from his throat:

"The secret recipe...Young Master...you need to crack...the secret recipe..."

He leaned back and fell silent.

(End of this chapter)