In the end, Li Fei still called Su Xue over, after all, this little girl also has her own unique views in this regard.

"Captain, I don't know anything, if I knew, I wouldn't come to you worried." But Su Xue herself was confused, she didn't have a good way.

"As a chemistry student, you should be able to help me figure out what's in my toothpaste." Immediately, Li Fei couldn't help but ask.

"Probably salt is alkaline, salt can play a certain role in sanitizing, and alkali can balance the acidic dirt in your mouth, and also has a whitening effect."

Su Xue said with a little speculation, of course, this is just her analysis and speculation, and she doesn't have a serious good idea.

"What do you want alkali for?" Suddenly, Li Fei was also a little curious, on the desert island, he felt that there were very few alkaline things.

As for the fact that salt can be disinfected, he knows that when he is accidentally injured in the wild, he will use sea salt to disinfect his wounds.

Su Xue just glanced at Li Fei, as if her professionalism had been questioned, so she didn't want to explain too much to Li Fei, a layman.

"Where am I going to get alkali, and I won't get this kind of thing?" Li Feidun was also a little embarrassed in time, embarrassed that he didn't learn chemistry very well in high school, and he was fishing in almost every class, so he was also a little embarrassed for a while.

"Stupid! Mixed with water and boiled and filtered, it is alkaline water!!" Su Xue had no choice but to explain patiently.

Li Fei, who suddenly realized, nodded, as if it was a little embarrassing for him to lose face in front of his own woman, so Li Fei did not continue to stay here, and went according to what Su Xue said.

For this toothpaste, almost the entire team went into battle, and it was obvious that they were all bothered by this matter.

Zhu Hao, on the other hand, found a wild boar carcass that he had hunted in the warehouse, and began to collect hair on its body with a dagger.

"Brother Zhu, what's the use of asking for wild boar hair? This thing is the same as a steel needle!!" Li Han, who was holding a large pile of bamboo tubes, couldn't help but ask.

The bamboo tube was just let by Li Fei to collect it, although he didn't know what to do with it, but he didn't ask too much and went.

"The captain is trying to figure out how to get toothpaste, I can't help much, but I think if there is toothpaste, at least there must be a toothbrush." Zhu Hao smiled, he leaned against a stone, and as he spoke, his movements did not stop at all.

"Make a toothbrush out of boar hair?" Suddenly, Li Han was also extremely curious, his eyes widened, and he asked.

"Of course, you'll see." At this moment, the preparation work is almost complete, Zhu Hao's hands-on ability is very strong, and the hard boar hair is as light as a needle and thread in his hand, and it is threaded through a piece of wood that has been cut to the size of a toothbrush shaft.

Soon, the first toothbrush made by Zhu Hao had been successfully launched, and he handed it to Li Han for the latter to inspect.

Feeling the hardness, Li Han also showed a very surprised expression for a while, and then said, "Yes, Brother Zhu, I didn't expect you to have this good craft!!"

Zhu Hao didn't show any proud look, nodded quietly and then began to continue the operation in his hand.

Everyone was busy with their own things, and the bored Li Han could only continue to pester Li Fei.

"You just happened to come over and help me look at the fire." Li Fei opened his mouth and said.

Immediately, he also quickly began to get up, and according to what Su Xue told himself, he began to pack the plant ashes in a package that could filter water, and put them in boiling water.

Suddenly, the whole pot seemed to be a little dark, and the originally clear water surface became a little muddy at the moment.

"Can this thing really extract lye?" Even Li Fei himself had some doubts in his heart.

But since he believed what Su Xue said from the beginning, he naturally wouldn't have too many doubts at this moment.

After about half an hour, he filtered the liquid in the pot once, and filtered out all the impurities inside.

He is no stranger to this operation, and this is the step of extracting fine salt by himself, so it is much easier to do it again.

Then Li Fei and Li Han slowly squatted down, looked at the filtered black bucket of water, and were somewhat silent for a while.

Although their education level is not very high, these things in front of them should not have much to do with alkaline water.

After all, the alkali they usually use is pure white in color, almost more crystal clear than salt.

Just when the two began to question whether the operation failed, Su Xue also rushed over.

"Captain, you are so powerful, the steps are not wrong, after a few filters, you can extract pure alkaline water!!" At the same time, her expression was full of surprise.

Because she knows this step best, she originally just let Li Fei try it with the mentality of giving it a try, and then she will do it herself in case she fails. ap.

Unexpectedly, Li Fei succeeded on the first attempt, and according to this color, the fire was mastered very well.

After receiving Su Xue's affirmative answer, Li Fei and the others finally breathed a sigh of relief, and at the same time, they both had some proud looks on their faces.

The next steps are not difficult, because it is not a difficult operation to filter out impurities after filtration, and they are already familiar with it.

After another hour, Li Fei looked at the milky white transparent liquid in front of him that had been filtered through layers and became extremely clear, and he was finally relieved.

All that's left is to get the salt out, because salt and alkali are obviously the two most important ingredients in the toothpaste that Su Xue said.

It's just that Li Fei thought about it, and it seemed that both sea salt and fine salt were very unsuitable for use in the production of toothpaste.

Because the taste of these two things is very strong, not to mention sea salt, it has a strong fishy smell, and it contains too many trace elements.

As for the fine salt, Li Fei also planned to do this at first, but after trying it, he found that the taste became even stranger.

So he suddenly remembered that when he was a child in the countryside, a very special kind of salt.

This kind of salt is different from table salt and sea salt, the taste is very fresh, and even has a little sweet taste, which makes Li Fei's eyes shine instantly.