When it was almost noon, the jar full of clear water had evaporated into half a jar.

Then, stop the fire, cool down, filter several times to remove the solid residue, then add water and add activated carbon.

After multiple impurities removal with activated carbon, the originally different-colored solutions became much clearer.

After the color removal is completed, the last step is to heat and cook.

The smoke in the house was choking, so Liu Bei and others stood outside waiting. Seeing the fire used in the house, Liu Bei was surprised. He asked, "Xi'er, didn't you say that boiling will destroy the properties of the medicine? Why use high fire?"

Li Mengxi smiled and explained, "That's true. Certain medicinal properties will be damaged if overheated.

But, how can we say that medicine will definitely become bad after being boiled?

The medicine in the willow tree is not afraid of boiling."

After hearing Li Mengxi's explanation, Liu Bei thought about it carefully and understood.

Because of the high fire used to cook it, the firepower is strong and the water steams very strongly.

By the afternoon, the clear liquid in the vat was almost gone, leaving only the bottom.

Then, transfer the clear liquid to a large bowl, and then put the large bowl over the fire to cook for a second time.

The remaining clear liquid, which was less than 10% to 20%, was dried up soon after.

At the critical moment, Li Mengxi moved around frequently to check.

He saw that among the dozens of branch extracts, some boiled to the end with nothing left, some boiled to produce some yellow solids, some boiled to pale green solids, and some boiled to the end,

There are some impurities left, and some of them are boiled to the end and boiled in the lake.

There are a total of thirty-nine kinds of trees, and there are twenty kinds of trees from which substances are extracted with clean water. Some of the twenty kinds of extracts are too small to distinguish whether they are impurities or substances, and some are sufficient, but either

The color is wrong or the shape is wrong.

For example, a pale yellow solid was extracted from pine bark. Li Mengxi didn't know what it was. No matter what it was, its color, shape, and medicine were very different from the medicine extracted from willow trees.

After a period of elimination, in the end, there were seven finished products that were close to willow extract. These seven extracts were all white, and at least in terms of color, they were close to the target product.

Li Mengxi took a look and found that white powder was extracted from seven species: willow, poplar, peach, elm, paper towel, birch, and ginkgo.

The next step of testing is to find typhoid fever patients and administer extracts from these seven trees to see if the medicine is effective.

But by this time, Li Mengxi hesitated.

The willow tree was first confirmed to be effective and indeed able to cure diseases, and then its ingredients were extracted.

However, these trees, such as poplar and peach trees, have no idea whether their bark is useful or not, and whether it is poisonous or not. If they are used recklessly, Li Mengxi is afraid of poisoning people.

Based on such worries, Li Mengxi was somewhat hesitant.

After thinking about it, Li Mengxi took the medicine to the military medical camp.

After finding Tian Bu, Li Mengxi handed a pile of bowls to Tian Bu.

He pointed at the bowls one after another and explained to Tian Bu, "For the first three bowls, I used willow bark, willow branches, and willow leaves to extract three bowls of medicinal powder. As a result, it seems that only the willow bark took out more.

Not much is extracted from the willow twigs and willow leaves.”

Tian Bu looked around and saw that in the bowl next to [willow bark], there was a layer of white medicinal powder at the bottom of the bowl. In the bowl next to [willow branches], there was a faint bit of medicinal powder. In the bowl next to [willow leaves], there was only some powder at the bottom of the bowl.

The specious green thing looks like the dried grass juice.

Li Mengxi said to Tian Bu, "After this test, it should be found that the medicine in the willow tree should be hidden in the bark, with few in the branches and none in the leaves."

Later, Li Mengxi pointed to other extracts and said to Tian Bu, "The other bowls are extracted from peach, elm, birch, ginkgo and other trees.

Tianbu, are these tree barks toxic and may they cause death?"

Tian Bu glanced at the note on the bowl, thought about it seriously, and replied, "No problem."

Tianbu said it was no problem, which means that barks such as peach bark and birch bark are either non-toxic or slightly poisonous and cannot kill people if eaten.

Li Mengxi nodded and said seriously to Tian Bu, "Okay, I'll leave the medicine to you. You can prepare and test the medicine. How should you test it? Do you understand?"

Tian Bu has already carried out a round of drug testing work. He is already familiar with this and is not unfamiliar at all.

Tian Bu solemnly accepted the task.

——

Li Mengxi gave Tian Bu seven portions of medicinal powder. According to the previous test method, to test the seven portions of medicinal powder, he needed to find seventy typhoid fever patients, then find ten more, take licorice water, and then find ten. If he didn't take the medicine, he would find thirty more.

One, take common cold herbs.

Altogether, more than a hundred patients are needed.

Fortunately, it is spring now, when diseases are common, and patients with wind and cold appear one after another. If not, there would not be enough people to test the medicine.

Tian Bu led a group of military doctors to select a total of two hundred young and strong men from the patients who came for treatment. Then, they checked their pulses one by one for several rounds, and selected more than a hundred patients suffering from stroke.

Then, according to the procedure of testing the medicine, Tian Bu set up tents in various places in the city, arranged the personnel, distributed food, bedding, firewood and other materials, and then led people to distribute the medicine everywhere.

Tian Bu personally handled the entire drug testing process.

When it was getting dark, Tian Bu had divided the medicine.

One night passed.

On the next day, Tian Bu rushed to various places early in the morning to investigate the condition.

Among the seven kinds of tree bark extracts, the peach tree was useless. Among the ten people who took the peach tree extract, not one of the ten patients with colds was cured.

Elm trees are useless.

Paper mulberry is useless.

Birch is useless.

Ginkgo bark is useless too.

When Tian Bu went to the tent where poplar bark was taken, after investigation, Tian Bu found that out of ten people in one tent, three were cured and the rest were all improved.

Tian Bu was surprised. He vaguely felt that poplar bark might be useful.

After the test was over, Tian Bu hurriedly went to Li Mengxi to report the test results.

When Li Mengxi heard Tian Bu say that things extracted from poplar bark seemed to be able to cure wind and cold, "Polar tree?" Li Mengxi frowned and looked at Tian Bu doubtfully.

Although the purpose of this test was to find a substitute for willow trees, when it was suspected that such a substitute had been found, Li Mengxi's first reaction was disbelief and full of doubts.

This chapter is not over yet, please click on the next page to continue reading! Li Mengxi ordered Tian Bu to take the poplar extract and find someone to try again, and Tian Bu followed the order and left.

Another day passed.

On the third day, Tian Bu came to report that there were forty patients with wind-cold. After taking poplar bark, twenty-one of them were cured the next day, and nearly 50% of them were cured.

At this point, Li Mengxi believed that the stuff extracted from poplar trees was probably the same thing as the medicinal powder extracted from willow trees.

I took the two medicinal powders together and compared them. They were both white powders. When the powders were rolled up, they felt the same. When I put them in my mouth and tasted them, I found they tasted similar.

Li Mengxi is almost certain that the medicine used to treat diseases in willow trees is also found in poplar trees in large quantities.

At this point, the test is over and the test was successful.

Willows are rare, but poplars are abundant in the north. With poplars as a substitute, the source of materials is no longer a problem.

The last remaining question is, what is this white powder extracted from willows?

Li Mengxi asked his younger brother, "Xiao Zhuan, what do you think this white thing is?"

Xiao Bian bit his finger and thought for a while, "What is it?" he asked Li Mengxi.

Li Mengxi smiled, "Yes, what is this?"

Old problems are solved and new problems arise.

With Li Mengxi's limited knowledge, he was asked to guess the types of substances. He felt that substances could be roughly classified into acids, bases, salts, greases and the like.

As for the method of judging the type of substance, if it is an acid, adding some alkali will neutralize it. I have forgotten what will happen if it is neutralized.

If the substance is a salt, such as calcium carbonate, calcium carbonate and acid will produce gas. Salts will bubble when acid is added.

A similar method can be used to determine the type of substance.

I don’t know whether it is necessary to test the properties of willow extract.

But, there is no end to the pursuit.

Li Mengxi began to clumsily test the properties of the drug with his younger brother.

They divided the medicinal powder into multiple portions, adding lime water to the first portion, and water to the second portion. After adding these two portions, Li Mengxi stopped. He scratched his head, feeling a little silly.

Something seems wrong. The medicinal powder was originally extracted because it was soluble in water and lime water. Now it is easy to add these two kinds of ingredients. There is a trick and it has been dissolved back.

Afterwards, Li Mengxi brought a bowl of distilled and concentrated white vinegar.

"Xiao Bian, let's pour the vinegar in and take a look."

"Okay!" Little Brick leaned over and stared with wide eyes.

Li Mengxi held the bowl and Kuaizi and carefully poured the white vinegar onto the medicinal powder.

Then, before Li Mengxi stirred the medicinal powder, the medicinal powder disappeared and seemed to have melted.
To be continued...