Tis'a took in the expressions of everyone present, seeing the complex anxieties etched upon their faces. Understanding what they were all thinking, yet choosing not to voice it, he said, "The name of this formulation is the Minor Longevity Potion. As the name implies, it can extend human lifespan. Based on extensive experimentation, drinking a single vial allows a person to live, on average, five standard years longer!"

For those living in the Empire, even if they had never personally consumed a Longevity Potion, its fame was legendary. Longevity Potions were categorized into four tiers: Minor, Moderate, Major, and Supreme. A Minor Longevity Potion was already a Rank Seven formulation, fetching a price of one hundred thousand Imperial Credits on the market. Following this logic, the Moderate Longevity Potion was Rank Eight, and the Major Longevity Potion was Rank Nine.

And the most ultimate of them all, the Supreme Longevity Potion, was a priceless Rank Ten formulation!

No Rank Ten Potion ever sold for less than one hundred million Imperial Credits, and they were invariably beyond price, commanding market scarcity. These potions offered the power of complete physical transformation, with astonishing results. A Supreme Longevity Potion could extend a person's life for up to a thousand years!

It was crucial to note that one should not consume multiple potions of the same tier. One dose was sufficient; the effect of a second dose would plummet to one-tenth its original potency, and any subsequent doses would become entirely useless.

Consequently, the high-ranking and powerful figures within the Empire would desperately seek out a single vial of the Supreme Longevity Potion. Yang Ying recalled reading a news report about an auction held in the Imperial Capital not long ago, where the grand finale item was a Supreme Longevity Potion. That single potion ultimately fetched the astronomical price of 1.1 billion Imperial Credits!

The primary reasons for this were twofold: firstly, few Apothecaries possessed the skill to brew Rank Ten potions; secondly, even if such an Apothecary existed, the materials required to concoct a Rank Ten Potion were exceedingly rare. Even within the Empire, which spanned half the galaxy, these materials seldom surfaced.

Decades of tens of thousands of years of excavation had long since depleted these rare materials. Some precious species had even gone extinct, consigning many Rank Ten formulas to history, only to be observed in the sterile environment of a laboratory.

The focus returned to the laboratory. After Tis'a announced the examination task—brewing the Minor Longevity Potion—the gazes of most students shifted.

If nothing else, the Minor Longevity Potion was the most profitable among all Rank Seven formulations. After all, who wouldn't desire a few extra years of life?

The Moderate Longevity Potion sold for significantly more than the Minor, placing it far beyond the reach of ordinary citizens. Therefore, mastering the method for the Minor Longevity Potion here meant that even failing the exam, the day would not have been wasted.

Among the students, only those from affluent families, who did not need to earn a living by crafting potions, or those brimming with confidence in their ability to pass the test and gain access to more profound formulas at the Academy, would regard the Minor Longevity Potion with indifference. Yang Ying, however, possessed a measure of both advantages, hence his expression remained the most placid.

Tis'a, knowing the calculations running through their minds, let out a cold snort and snapped his fingers. Over a dozen robots entered, pushing small carts laden with all the materials needed for potion formulation.

The robots distributed the supplies, one set for each workbench. Once the distribution was complete, Tis'a announced, "Now, watch me work. Everything required for the formulation, aside from what is already on your workstations, is inside your drawers."

He put on a pair of transparent gloves—a specialized item for Imperial Apothecaries. Utilizing a unique technology, these gloves offered protection against corrosive substances generated during the process without impeding tactile sensation.

Yang Ying also retrieved a pair of gloves from his drawer and put them on.

Tis'a began selecting materials from the pile, stating, "You are all likely aware that potions from Rank One through Six, and even some Rank Seven potions, are already mass-produced by mechanized equipment within the Empire. However, the remaining portion of Rank Seven potions, and those of higher ranks, remain stubbornly resistant to mass production. This is precisely why we, the Apothecaries, still exist."

As he spoke, the students nodded in unison, acknowledging this as basic knowledge. Suddenly, Tis'a's eyes sharpened, and he asked, "But do you know why this is the case?"

A young woman seated near the front addressed his question: "Because nothing in the world is perfectly identical. Even the same material possesses subtle variations in its inherent properties. Low-grade formulations do not have high sensitivity to these material variances. From Rank One to Six, including some Rank Seven potions, success only requires the ability for precision processing—accurately matching the ratio of medicinal components. The large machinery in the pharmaceutical factories can handle the production of these potions."

"However," she continued, "as the rank of the potion increases, the required precision regarding material properties also rises. For some Rank Seven and higher formulations, mere precision processing cannot resolve the disparities in the intrinsic qualities of the materials. Sometimes, materials that appear identical under instrumental analysis yield wildly different results when used in a potion. The higher the potion's rank, the greater the intolerance for variations in inherent properties. At this point, the Apothecary must use their spiritual energy to perceive the material's properties to successfully complete the formulation."

"Well said!" Tis'a’s stern expression softened slightly.

The young woman allowed a faint smile to grace her lips, aware that she had just earned considerable positive impressions from the examiner.

"High-grade potions no longer rely solely on precision processing," Tis'a resumed. "However, the requirement for spiritual processing varies among different formulations. Take today's exam subject, the Minor Longevity Potion: only a few critical steps demand spiritual processing and must be done manually. The rest of the steps can be accomplished entirely using the instruments on your tables."

"In summary, the Minor Longevity Potion requires ninety percent precision processing combined with ten percent spiritual processing to achieve successful formulation. This is merely a Rank Seven potion. As the rank increases, the demand for spiritual processing will likewise escalate. Rank Ten potions, in fact, require purely manual construction; using machinery for even the smallest step in a Rank Ten potion is nothing short of sacrilege and a waste of rare materials."

While speaking, Tis'a used a machine to weigh several herbs, toss them into a grinder, and then transfer the resulting powder to a container. He added a certain reagent and brought the mixture to a boil for about five minutes. Next, two mechanical arms collected and filtered the liquid from the container, separating the dross to extract the filtrate. After cooling, it was moved to another container, where another reagent was added. The container was sealed and shaken vigorously twice. The two reagents added were immiscible; the second reagent was extracting several medicinal components dissolved in the first.

The glassware used in the Imperial Laboratories differed greatly from that on Earth. Apart from basic beakers, test tubes, and funnels sharing similar shapes, other instruments were markedly different, and their construction material was not glass, but some form of more stable, transparent synthetic composite.

The preceding steps were all executed automatically according to pre-set programs within the machines. Tis'a's role was essentially to deposit the raw materials, set the operational mode, pose questions, listen to the young woman's answers, and then continue his commentary, much like delivering a lecture.

Following this procedure, and after many more operational steps, the materials underwent programmed heating and cooling within the machinery, underwent various reactions, and the products were mixed, separated, purified, concentrated, and precipitated. Throughout this, Tis'a explained the significance of each step while introducing several more reagents and materials.

About half an hour later, he had utilized four separate machines and extracted three small cups of solution and a small pile of powder. Tis'a carefully labeled the three small cups of solution and declared, "The precision processing stage is now complete. What remains is the spiritual processing—the most crucial step is upon us. Those who wish to pass the examination, pay close attention now."

All the students' attention was captivated. After his announcement, Tis'a raised two small beakers and poured the contents of the No. 2 solution into the small cup containing the No. 1 solution. His movements were incredibly smooth, his concentration absolute. As he poured, he simultaneously shook the No. 1 cup at a steady rate.

As the liquid in the No. 2 cup diminished, the solution in the No. 1 cup began to cycle through a dazzling spectrum of colors, shifting through nearly three distinct hues every second, none repeating.

Tis'a’s movements slowed until he finally ceased. The solution in the No. 1 cup now displayed five colors, continuously morphing. A small amount of solution remained in the No. 2 cup, which he ignored. He set the No. 2 cup down and picked up the pile of powder. "The solution in the No. 1 cup is currently in an activated state; the next step must be performed swiftly, or the medicinal efficacy may be lost."

He levitated the powder using his mental energy (Nian Li), adding half of it into the No. 1 cup, and shook it briefly. The powder dispersed rapidly. Feeling it wasn't quite enough, he added a little more. Thanks to his Nian Li, Tis'a could clearly control the exact amount added each time, avoiding the disaster of accidentally dumping in a large quantity when intending only a pinch due to a slight tremor of the hand.

After adding powder three times, Tis'a felt the amount was sufficient. He then slowly poured the solution from the No. 3 cup into the No. 1 cup while explaining, "For an Apothecary equipped with spiritual power, much effort can be circumvented. High-level Apothecaries can directly use spiritual energy to heat or cool materials, and they don't even require containers, mixing substances directly in the void. This allows for the best sensing and control over the reaction process. If a formulation is on the verge of failure, an inner warning will signal the danger."

"Apothecaries lacking spiritual power find it difficult to brew high-grade potions. Even if they are highly experienced and manage a successful batch once or twice, their performance will never remain consistently stable. The success rate will always be lower than that of an Awakened Apothecary. Viewed from another angle: if an Apothecary can manage high-grade formulations without being Awakened, wouldn't they perform even better once awakened? I don't know if any untested, non-Awakened students are participating today, but if you are, do not despair after hearing my words. As long as you pass this examination, the Academy will provide top-tier Gene Activation Potions for your awakening."

As his voice trailed off, a burst of seven-colored rainbow light erupted from the No. 1 cup. A multitude of brilliant colors shone in Tis'a's eyes. He set down the partially used No. 3 cup and announced, "The formulation is complete."