"Once it's filled with liquid, you just need to insert it into a vein, slowly press, and then you can inject the garlic juice into the human body."

"Main body? Front needle?"

Listening to the drawings made by Xu Yun, Old Su was stunned again, only realizing that he might have misunderstood.

He awkwardly coughed lightly and looked at the drawing made by Xu Yun.

The Halo granted Xu Yun the ability to understand ancient texts after traveling through time, but it didn't enable him to master writing and drawing, so the sketch made with a brush had the charm of a 'soul artist'.

Although crude, some key details were described passably.

Actually, in ancient Huaxia, the ancients did attempt to create syringes.

However, the syringes of that time looked vastly different from those of later generations:

The 'tube' of the syringe was actually made of sheep bladders, with tubes made from animal intestines.

It was more akin to a squeezer for measuring blood pressure rather than a syringe.

This ancient syringe used bird bones, hollow inside, which facilitated the infusion process quite well.

Though slightly finer than the ancient handmade needles, using it was still excruciatingly painful.

In local history, the true concept of a modern syringe wasn't proposed until the 15th century by Italy's Caddenil.

It wasn't until 1853 that the Gaul Pula Waise invented the piston-type hypodermic syringe, made of pure silver.

Therefore, the syringe drawn by Xu Yun could be considered a new invention, quite ahead of its time for ancient people.

Most people might not even understand what it is.

But remember.

The principle of a syringe is actually very similar to that of an air pump, and Old Su is someone who can fiddle with self-priming pumps.

So within a few seconds, he clapped his hands lightly, grasping the operating principle:

"Marvelous, marvelous, drawing air in by pulling and then injecting it into the body using the momentum of crossing a hill...

Such an ingenious creation, even if Hua Tuo and Bian Que were alive, they would be thrilled, wouldn't they?"

Students who elected to take a course on the history of ancient Huaxia physics should know.

Over the hill.

This term was actually the ancient rudimentary understanding of atmospheric pressure.

Though human knowledge of atmospheric pressure was shallow at the time, the concept of over the hill referred to valley winds.

Though, in strict terms, it's related to thermal circulation, not the broader atmospheric pressure.

Given the limitations of the background, recognizing this with the scientific level of the ancient era was already commendable.

At this point, Europe was still in the Middle Ages, and there, the understanding of wind was still the touch felt from the souls of the dead.

After some thought, Old Su said to Xu Yun:

"Wang Lin, I vaguely understand a bit about the principle of this object, crafting the tube is not difficult, but how should the needle be made?

As you mentioned, the needle is only slightly thicker than a hair. If it were a solid needle, it wouldn't be difficult; I have silver needles of this kind in my hand.

But if it's hollow inside..."

Seeing the curious expression of Old Su, Xu Yun smiled softly at him:

"Sir, are you familiar with sea urchins?"

"Sea urchins?"

Old Su was momentarily stunned, blinking quickly:

"Is that the sea creature covered in spines? I've seen it a few times...

Wait, I understand now, are you planning to use its spines to make the needle?"

Xu Yun nodded emphatically:

"That's right, exactly that."

The sea urchin, known to later generations.

Sea urchins can be found throughout the global ocean, visible in both Asia and Africa.

In recent years, sea urchins have appeared in cuisine both in our country and in other countries.

In the words of some gourmets, sea urchins are crowned as the supreme delicacy among seafood.

However, in ancient Huaxia, sea urchins were merely used as medicinal ingredients and not as a common food.

Only extremely poor fishermen would consume sea urchins when food was scarce.

Many people didn't know this.

Sea urchins have existed on Earth even before the emergence of dinosaurs, their history is quite ancient.

Of course.

They differ somewhat from cockroaches.

Currently, sea urchins generally fall into five categories:

Sh*t sea urchin, purple sea urchin, northern purple sea urchin, red sea urchin, and long spine sea urchin.

The sh*t sea urchin and purple sea urchin are considered common, long spine sea urchin grows fastest, and red sea urchin is the least seen in the market.

Additionally, what many people do not know is...

Sea urchin spines are actually a natural type of needle.

Or more accurately.

The spines of red sea urchins are a natural type of needle.

The spines of sea urchins are columnar protrusions formed after the calcification of connective tissues, connected to the body's venom glands, and can very easily pierce human skin.

When a spine pierces the skin and injects venom, it can cause dermatitis and other associated symptoms.

Every year, a large number of "how to deal with sea urchin stings" questions appear online, especially in some coastal cities.

In later generations, most medical needles range from size 5.5 to 7 with diameters between 0.30mm and 0.51mm.

While the tip of a red sea urchin spine is about 0.38mm to 0.42mm, fitting the standards for intravenous injection.

So, in ancient times when the technology to create sharp hollow needles was not available, sea urchin spines were undoubtedly the best choice.

Although red sea urchins are primarily found in Neon, maritime trade in the Song Dynasty was quite prosperous, and by the Southern Song period, it even became one of its key industries.

In those years, many maritime merchant fleets regularly traveled between Korea and Danluo, and although there were fewer fishing boats, these journeys occasionally brought rare sea goods back to the Great Song.

Bianjing, as the core city of the Song Dynasty, had a level of blood supply... ahem, on par with the support Hebei provided to Yanjing in later generations.

So just by putting in some effort to find them, obtaining some red sea urchins wasn't difficult.

Of course.

The spines of sea urchins are easily able to pierce the human epidermis, but they are also extremely fragile and can break into pieces with a little force.

So, before the formal injection, two more tasks need to be taken care of:

Finding the red sea urchin, plating the 'needle' with aluminum to strengthen it, and preparing saline solution.

Exactly.

Saline solution.

After all, unlike oral and topical applications, intravenous injection doesn't mean just pouring the liquid into the tube and directly injecting it into the bloodstream.

Before intravenous injection, the liquid must be integrated into diluent or infusion fluid, then the next step of injection can proceed.

The principle is simple, it relates to osmotic pressure:

Human blood isn't simply pure water; it contains various substances, thus having a certain osmotic pressure.

If osmotic pressure changes, it can cause an imbalance inside and outside the blood cells, leading to cell rupture.

The solution used for infusions, 0.9% sodium chloride, has an osmotic pressure close to that of blood, and such a solution ensures no significant change in blood osmotic pressure.

Similarly, there's the 5% glucose solution, which biology teachers have probably lectured on countless times in class.

Under certain circumstances, coconut water can serve this same purpose.

Additionally, in the movie "Who Am I," after a driver gets bitten by a venomous snake, Uncle Long uses coconut water instead of glucose for infusion treatment.

In his past life, Xu Yun once asked a writer friend known by the pen name Bai Yi Xue Shi... White Robe Scholar about this when writing a book.

This person, in reality, was also about to reach a director-level position as a doctor.

Highly skilled in medicine, but with a high hairline.

In Xu Yun's writer group, people would often seek his advice, getting a free director's consultation.

At the time, he told Xu Yun.

Examples of using coconut water after snake bites have been noted in movies, but actual intravenous injections are not as simple as just pouring medication into a tube and injecting it into the veins.

Although intravenous injection isn't merely pouring the solution into the tube and injecting it into the bloodstream directly.

The rationale is straightforward, related to osmotic pressure:

The 5% glucose solution is another similar solution, as mentioned in class, that maintains osmolarity.

In emergencies, physiological saline is regarded as the best measure.

Of course.

The materials required for this part can be thought of in many ways.

For example, as long as you have hands...

Rub your hands to generate electricity...

It seems I underestimated everyone, I'm glad I didn't arrange an extra reward.

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