Three Kingdoms: A Million Soldiers Grown from the Fields

Chapter 181 The Rubber Workshop
In late April, Jinyang was bathed in the beauty of spring. Willow branches along the banks of the Fen River sprouted tender yellow buds, and busy figures could be seen everywhere in the fields.

Zhang Xian, however, plunged headlong into the Craftsmen's Camp in the west of the city, a secluded workshop deliberately cleared out of the hustle and bustle.

The air was filled with the raw, earthy scent of soil, grass, and roots, mixed with the fresh aroma of freshly planed wood.

In the center of the workshop, a huge earthenware jar was soaking the precious rubber grass roots that he had harvested twice from his home and fields, weighing forty or fifty pounds.

These rhizomes have a yellowish-brown skin and a shape somewhere between a robust ginseng and a twisted old ginger, emitting a rich, slightly spicy aroma.

Zhang Xian rolled up his sleeves and trouser legs, revealing his muscular calves, and wore a pair of straw sandals.

Standing by the jar, his expression was as focused as if he were facing a priceless treasure.

Surrounding him were several of the most skilled and trusted craftsmen in the workshop: Lu Da, blacksmith Lao He, and meticulous pottery master Sun Tao.

The group looked at the grass roots in the jar with deep confusion and a hint of barely perceptible awe on their faces. Something that could make the magistrate take such a serious and personal action must be extraordinary!
"My lord, can these...grass roots really produce such a precious, resilient, and elastic treasure?"

Lu Da couldn't help but ask.

Zhang Xian scooped up a rubber plant root as thick as a child's arm from the jar, weighed it in his hand, and found it to be quite heavy.

He pinched a small part of the root bark with his fingers, and a very fine, milky-white, viscous sap immediately seeped out from the broken end, forming a thin, white thread on his fingertip.

“Look.” Zhang Xian held his finger up in front of everyone’s eyes, it had a sticky feel to it.

"This is the prototype of glue. Our job is to extract as much glue as possible from the roots of this grass!"

His voice carried a sense of certainty and barely suppressed excitement.

If he could discover rubber, he could immediately turn his attention to researching steam engines.

With the steam engine, many things that were considered miraculous for this era were also able to come into being!

Take the soaked rubber grass to a newly built shallow pool in a corner of the workshop.

Zhang Xian personally demonstrated by immersing a handful of rubber grass roots in the clear well water and carefully scrubbing away every grain of soil adhering to the roots with a specially made stiff-bristled pig bristle brush.

The movements should be gentle and swift, ensuring the roots are cleaned thoroughly without excessively damaging the delicate root bark and causing the loss of the gelatinous substance.

"Remember, you must clean the mud from the crevices between the roots, especially! If even a little mud or sand gets in, the adhesive will be ruined!"

Zhang Xian's voice was exceptionally clear amidst the rushing water.

All three were craftsmen who made a living through their skills, so this kind of work was not difficult for them at all. After trying it once or twice, they all became proficient.

After cleaning, the next step is crushing.

This is a crucial step in releasing the gel.

The best bluestone mortar in the workshop was brought in, and the pestle head was replaced with the heaviest and smoothest hardwood pestle.

Zhang Xian placed several thick grass roots at the bottom of the stone mortar.

"Old He, come here!" Zhang Xianxian gestured to Old He.

"Hold back the force when you swing the hammer to strike the iron. It's about using skill! Not smashing the iron! You need to crush it, but don't crush the grass and sap inside too much, as that will affect the gelatinous substance. You need to let the sap inside flow out! Like pounding medicine! Understand?"

The most suitable method for extracting rubber grass is to cut it into thin round slices and soak them in an extractant solution. However, since Zhang Xian cannot do this at present, he can only use primitive methods.

"I'll give it a try, Lord Zhuang."

From Taoyuan to Jinyang, He the blacksmith still habitually called Zhang Xianzhuangzhu.

Old He took a deep breath, gripped the wooden pestle tightly, and tried to strike it down.

With a muffled thud, the grass roots in the stone mortar shattered, and sure enough, more milky white sap seeped out from the broken ends, sticking to the pestle and the wall of the mortar.

"Yes! That's the right amount of force! But make it more even, don't just hit one spot!" Zhang Xian stared intently.

Old He steadied himself, his arm muscles tensed, and he controlled his strength, beginning to rhythmically pound, grind, and polish.

The heavy wooden pestle seemed to come alive in his hands, each strike perfectly crushing the woody parts of the grass roots without turning the fibers into a paste.

The milky white juice, mixed with the crushed fibrous tissue, gradually gathered at the bottom of the mortar into a thick paste, emitting a stronger grassy smell.

Lu Da carefully scooped out the mashed grass root paste with a wooden spoon and poured it into a large wooden basin lined with a fine double layer of burlap that had been prepared next to him.

Zhang Xian then picked up a fresh grass root, quickly peeled off the rough outer skin with a knife, leaving only the relatively white and tender inner core rich in gelatin, and threw it into the stone mortar.

"The outer skin has little glue and a lot of fiber, which affects subsequent purification. We should cut it off if possible! The inner core is the real treasure!"

He explained quickly and efficiently.

Sun Tao immediately followed suit, picked up a knife, and began processing the next batch of grass roots.

The mixture of crushed grass roots was transferred to a wooden basin lined with two layers of fine linen.

Zhang Xian took out a large bucket of freshly boiled and cooled water and slowly and evenly poured it over the paste.

"The water needs to be warm! If it's too hot, the glue will denature and solidify; if it's too cold, it won't dissolve!" He poured water while slowly stirring and pressing the paste wrapped in burlap with a smooth wooden stick.

The warm well water quickly soaked through the grass root paste, diluting the milky white liquid. The liquid, mixed with water, seeped through the burlap and dripped into the large earthenware jar below.

The originally clear water immediately turned into a turbid, milky-white suspension.

He repeatedly poured water, stirred, and squeezed the water until the water that had been poured in became mostly clear before he stopped.

At this point, only the fiber residue, completely drained of its gelatinous substance, remained inside the burlap bundle, resembling damp, rotten straw.

These things are still good. In addition to rubber, rubber grass also contains a lot of inulin. It's just a pity that Zhang Xian only focuses on rubber now, and the use of inulin can only be put on hold.

However, these straw fibers after being extracted and dried are also excellent feed.

The large earthenware jar below was filled with a murky, milky-white liquid.

"Master Sun, it's up to you now!" Zhang Xian looked at Sun Tao.

Sun Tao had already prepared several large-mouthed, small-bottomed, smooth-polished clay pots.

He carefully scooped out the milky white suspension from the large earthenware jar with a long-handled wooden spoon and slowly poured it into the clay basin.

The murky liquid rippled in the basin, while tiny grass root fibers and mud particles slowly sank under the influence of gravity.

“The walls of the clay basin are smooth, so impurities don’t easily adhere and sink quickly,” Sun Tao explained, adding that this was his area of ​​expertise.

Everyone held their breath and waited.

As time passed, the liquid in the basin separated into layers. At the bottom, a layer of grayish-brown impurities settled, in the middle was a slightly turbid liquid, and on top floated a thin layer of slightly yellowish milky white liquid.

Zhang Xian used a thin bamboo tube to carefully avoid the sediment at the bottom and the turbid layer in the middle, only drawing out the clear liquid from the top and pouring it into another clean clay basin.

This process of clarification and absorption is repeated, with each repetition increasing the transparency of the liquid until the color becomes closer to a pure milky white.

A faint, unique aroma, reminiscent of raw potatoes or some kind of plant root, wafted through a corner of the workshop.

This process, which required extreme patience, took up most of the day.

When the last batch of clarified liquid was poured into a brand new, dry earthenware jar, the liquid in the jar had a soft, uniform milky white luster. Although there were still some microscopic dust particles that were difficult to see with the naked eye, it was completely different from the initial turbid liquid.

"It's done! This is the latex liquid!" Zhang Xian looked at the milky white liquid rippling in the vat, let out a long sigh of relief, and showed heartfelt joy on his face.

After extracting the latex, we move on to the most crucial step.

Zhang Xian had already prepared a plan for how to make the water-soluble glue re-coagulate into a block.

He took out several flat ceramic plates of suitable size, the bottom and inner wall of which were polished as smooth as a mirror.

He then took out several small earthenware jars, each containing a different item: a jar of rice vinegar, a jar of alum powder used as a medicinal ingredient in this era, and a jar of boiled peach gum liquid.

The three substances represent acetic acid, hydrochloric acid, and colloid, respectively.

"Let's see which one works!" Zhang Xian's eyes gleamed with the light of experimentation.

He carefully poured the clarified latex liquid into three prepared ceramic dishes, the liquid level about one finger deep.

He added a small amount of rice vinegar to the first ceramic plate.

When the milky white liquid came into contact with the acid, it reacted immediately. Extremely fine white flocculent matter began to appear on the surface, like the first snowflakes falling. However, the flocculent matter was very small and settled extremely slowly. After a long time, only a thin, shapeless soft film was formed, and most of the gelatinous substance remained dissolved in the water.

"Not enough acidity? Or too slow?" Zhang Xian frowned.

For the second ceramic dish, he sprinkled in a small pinch of alum powder.

The fine white powder dissolves instantly in water, and the latex liquid in the dish changes almost instantly as well!

The originally uniform milky white liquid visibly coagulated into irregular, tofu-like white flocculent clumps, which quickly sank and separated from the clear water on top! The effect was immediate!
"Great! This is fast!" Old He couldn't help but exclaim.

Zhang Xian's eyes lit up. He gently stirred the lump with his chopsticks. The lump was soft, but it had already begun to take shape.

He carefully skimmed off the clear water that had separated from the top.

For the third ceramic dish, he added some melted peach gum liquid.

After mixing the two, the latex solution seemed to become more viscous, but there was no obvious solidification. However, after standing, there were signs of extremely slow sedimentation at the bottom, which was far less efficient than alum.

“It seems alum is the best choice!” Zhang Xian decided.

He immediately took out all the remaining latex liquid from the large earthenware jar and poured it into several prepared large earthenware plates. Then, Sun Tao precisely controlled the amount of alum powder and sprinkled it evenly and in small amounts into each plate.

As the alum powder dissolved, the calm, milky-white liquid surface was instantly rippled with countless fine white ripples, as if an invisible pebble had been thrown in! These ripples quickly expanded and connected, and within a dozen breaths, the entire liquid surface completely transformed into a flocculent, semi-solid white curd!

Clear water quickly seeped out from the gaps in the curd and floated on top.

"Amazing! Absolutely amazing!" Lu Da was dumbfounded.

A smile also broke out on Zhang Xian's face.

He carefully tilted the earthenware plate and slowly poured away the clear water that had separated on top.

At the bottom of the plate, all that remained was a moist, soft, white, slightly trembling lump of rubber.

He carefully scraped off the clumps with a specially made wide, thin bamboo strip and collected them on a bamboo tray covered with clean, fine linen.

The scraped-off clumps have a very high water content; they are soft and mushy, and will deform and release water when squeezed.

Zhang Xian piled it on a piece of fine linen, wrapped it tightly like a bundle, and then placed it on a thick, smooth bluestone slab.

"Old Lu, go!" Zhang Xian showed Lu Da.

Lu Da understood and immediately found several thick wooden boards of suitable size in the crafts camp.

He placed the burlap bundle containing the wet rubber block on the bluestone slab, then placed a thick wooden board on top, and then stood on it! Using his entire body weight, he slowly and evenly pressed down!

"Squeak...squeak..." A faint sound of water seeped from the burlap wrapping, and clear liquid flowed down the edge of the stone slab.

Lu Da continuously adjusted the position to ensure that every part was subjected to uniform compression.

Repeatedly stomp on the bag until no more water comes out.

Unwrapping the burlap revealed that the rubber block inside had been compressed into white sheets of uneven thickness and irregular shape, becoming much firmer but still soft and moist, like a thick, wet dough with the texture of the burlap still on the surface.

"It can't be exposed to the sun yet!" Zhang Xian stopped Lao He, who wanted to move the film into the sun.

"The sun is too strong; direct sunlight will harden and crack the surface while the inside remains damp, turning it into waste! It needs to be air-dried in the shade!"

He directed Sun Tao to set up rows of fine bamboo blinds in the most ventilated and shady corner of the workshop.

Carefully spread out the white, damp film, after pressing out some of the moisture, on the bamboo mat.

Next, it will have to be left to air dry naturally.

Time seemed to slow down again. Only the faint sound of the wind and the breathing of the people remained in the workshop.

Zhang Xian stayed close by, occasionally touching the edge of the film with his fingers to feel its changes in humidity and elasticity.

Lu Da, Lao He, and Sun Tao also took turns on duty to prevent mosquitoes and dust from falling on the film and to prevent the film from sticking together.

As the day passed, the edges of the wet film began to curl slightly, the color changed from pure white to slightly yellow, and the texture became a bit stiffer, but the center remained soft.

Two days later, the film became flexible and elastic, and its color turned into a uniform light yellow. It was no longer sticky to the touch, and it could feel good resilience when bent. After being released, it could slowly return to its original shape!

Become!

When a piece of rubber, about the size of a mouse pad, is carefully peeled off the bamboo curtain.

Zhang Xian took it in his hand and pulled hard! The film was slowly stretched, showing excellent elasticity! When he released his hand, it slowly returned to its original shape! When he kneaded it harder, he felt a full and elastic resistance, but it did not deform after he released it!

"Haha! It's done! This is rubber!" Zhang Xian finally burst into laughter, his voice echoing throughout the workshop, filled with an indescribable sense of accomplishment and joy!

He repeatedly stretched, kneaded, and rolled this precious piece of rubber, feeling every characteristic of the rubber grass!
The three students from Lu Da also gathered around, their eyes wide open, and carefully took the light yet seemingly heavy piece of film.

Old He tried to pinch the film hard with his calloused fingers, which could crush walnuts, but only left a shallow mark on the film surface, which quickly disappeared! He was amazed.

"A divine object! It's truly a divine object!" Old He murmured.

"Tough and elastic...like glue...what you said is absolutely right!" Lu Da excitedly stroked the smooth surface of the film.

"Fifty catties of grass roots...and this is all that was produced?" Sun Tao said regretfully, looking at the rubber sheet that weighed less than two catties.

Zhang Xian took the film and weighed it in his hand: "It's a bit too little. These fifty catties of fresh roots only yielded a little over two catties of dried glue."

But this is just the beginning!

He stepped out of the shade.

The warm April breeze carries the scent of earth and grass.

He looked out of the city and seemed to see that uncultivated saline wasteland.

"Those barren, saline soils where no crops can grow are so desolate that not a single blade of grass can survive, and nobody cares about them!"

"But these rubber grasses just love to grow there! Even if one acre of saline-alkali land only yields twenty catties of dried rubber, ten acres would yield two hundred catties! One hundred acres would yield two thousand catties! And ten thousand acres?!"

He turned around and looked at the three of them.

"Order the Agricultural Bureau to demarcate the largest saline-alkali land outside the city! Once the rubber grass seeds are harvested, immediately begin large-scale planting!"

"Lu Da, Lao He, Sun Tao! Within three months, the three of you will be in charge of training rubber workshop craftsmen. You can use all available manpower and materials! Before the autumn harvest, train a group of craftsmen who know how to make rubber, and also come up with a more labor-saving and efficient rubber-making process and tool drawings!"

"Yes!" the three responded in unison, their voices loud and clear.

(End of this chapter)