Although the heavy rain had stopped, it brought enough fresh water but also some troubles!
The damp crevices made survival difficult, so Lu Zhe could only choose to retreat for some time.
Ning Shu comforted: "Lu Zhe, I think there's no need to worry. Let's just stay here for now. It's quite nice even with less stuff, right? We can still make lots of bamboo products. Can you teach me how to weave bamboo baskets later?"
"That's no problem at all. I'm worried about our future salt sources, because we used up too much cooking salt for electrolysis, exceeding the budget. We don't have much salt left now. It’s fine in the short term but not a long term solution."
Ning Shu nodded and said, "People in ancient times rarely got to eat salt, but they still multiplied to the present."
"Only the rich in ancient times could eat salt. The poor extracted potassium salts from plant ash and nitrate salts from stones near feces. But none of those are healthy salts, so their life expectancy was not very long either," Lu Zhe explained.
Ning Shu quickly waved her hands: "No way, the taste is too strong."
Lu Zhe sighed, "If we really run out of salt, we'll have to eat those two kinds of salt."
"What? Isn't there another way?"
"There are still ways. Let's discuss it when we get back. For now, use phones as little as possible, super battery saving mode, minimize power consumption as much as possible."
"Got it!"
Back at the camp, Lu Zhe found only a thin layer of salt left at the bottom of the bottle, enough to season two home-cooked meals!
Jiang Yao said, "Can't we just not eat salt? I prefer light flavors."
Lu Zhe said, "It's fine for a day or two occasionally, but long term, you'll have no energy to do anything, greatly affecting survival efficiency. In the long run, it can also lead to various illnesses."
Shen Bing thought for a moment and said, "Why not go to the seaside again?"
Lu Zhe nodded: "I thought of that too. The rest of you stay here while one companion and I find the shortest route from here to the seaside and get 10-20 bottles of salt before coming back, enough to last a year."
"But we currently face two problems! First, the forest needs a few days to absorb the excess rainwater from the downpour, making it too dangerous to enter during this time. Second, while it's easy to find the route to the seaside, it'll be very difficult to find our way back. The inland area of this island is too big with too many similar terrains, making it easy to get lost in the woods."
Shen Bing nodded: "Then what else can we do?"
"The best way to obtain salt in the woods is to find salt mines."
"How do we find them?"
"We can track wild mountain goats and such. They regularly lick salt mines."
"Are there wild mountain goats on this island?"
"Don't know. Haven't seen any so far."
"Can we find them ourselves?"
"The probability is too low."
"Oh right, aren't there monkeys? How do monkeys get salt?"
"Monkeys get small amounts of salt from fruits and plants, then recycle the excreted salt!"
"I know that. They pick salt grains off each other's bodies to eat!"
"That's right!" Lu Zhe nodded. "Let me add, monkeys will also drink their own and companions' urine when desperately lacking salt."
"Oh my, why teach me such weird knowledge?"
"Too brutal!"
"Lu Zhe, we aren't doing that, are we?"
Lu Zhe agreed: "Too disgusting! I can't stand it either!"
"Humph, you can obviously take it!"
"It was a matter of life and death back then!"
"Hmm?" Shen Bing was taken aback. "Seems I discovered something shocking! By the way, did Bear Grylls and Ed Stafford ever talk about this?"
"They never survived for long. Unlike us who have to stay here a while, they mostly ate meat with trace amounts of salt."
Ning Shu suddenly remembered something. "I recall Bear found salt in a volcanic crater. Don't we have one too?"
Jiang Yao sighed, "The volcano is further than the seaside, right?"
"Oh right, Ed survived three months on a deserted island!"
Shen Bing thought for a moment. "That time he was already at the seaside. Shellfish, shrimp, crabs all contain salt. He occasionally licked his arms, shoulders and chest for salt too."
Guo Er was surprised. "Chest? How'd he reach it?"
Jiang Yao shrugged, "Not that hard, right?"
Ning Shu said helplessly, "With his hands, obviously!"
Lin Qianqian said, "We're better off. We can lick salt off each other!"
Ning Shu sighed, "Qianqian, don't have other motives when discussing survival!"
But Lu Zhe said, "What Qianqian said isn't entirely unreasonable. For now, we should minimize salt loss as much as possible!"
Jiang Yao worried, "You aren't having us pick salt off each other or drink that stuff like monkeys, right?"
Lu Zhe shook his head. "Of course not. We're humans. Humans should use human methods!"
Tang Xiaoguo nodded, "I see, catch a monkey and pick salt off it!"
Ning Shu said helplessly, "Xiaoguo, stop suggesting. Lu Zhe, tell us your method!"
"Listen to me!" Lu Zhe's tone was solemn and heavy.
"Urine is roughly 96% water, 1.5% inorganic salts, 2% urea, trace amounts of uric acid, proteases and glucose. Drinking a little can save lives when extremely thirsty, but drinking too much burdens the kidneys severely. Also, the taste is too strange, so I strongly advise against directly drinking it!"
The girls shrieked:
"We never planned on drinking it!"
"Also, how do you know the data so precisely?"
"You can't be that into chemistry!"
"Why did I take liberal arts!"
Shen Bing was the calmest: "Then what will you do?"
"Leave the urine out in sunlight. Water and enzymes will decompose urea into carbon dioxide and ammonia gas! That's the stinky smell.
Once the foul odor is gone, most urea is removed too. The remaining yellow crystals are mainly salt. Add water and filter through cloth to remove urochrome, and you'll get table salt. It's mostly sodium chloride, much safer than potassium and nitrate salts. Oh, and girls your age don't produce much uric acid, so we can ignore that."
After Lu Zhe's lengthy explanation, the five girls were dumbfounded.
This was their first time learning there's such a bizarre method of obtaining salt!
"The taste is too strong, hard to accept for some reason!"
"Me too..."
But Lu Zhe was indifferent. "Think of it this way. In the ocean, countless fish constantly excrete everywhere. Even the salt we get from the ocean may have come from fish urine!"