It's not that hard to open a hospital in another world, right?

Chapter 137 High~~ Potassium manganate, the method of making oxygen (first update)
The necromancer took Gretel away involuntarily, muttering and complaining all the way.The yelling didn't stop until they entered their own tent, dragged out a suitcase from the bed, and dumped it on the table with a clatter:
"These are my trophies! Come and see what you can use, just take it away!"

Under the candlelight, all kinds of rings, necklaces, and amulets are dazzling, making people suspect that he robbed the jewelry store.

Gretel slowly opened his mouth wide.He looked at Lynn, then at the pile of things on the table, and then at Lynn—how many people did you kill?It's been less than a month since the war started, you're not going to be a scout, you're going to kill people!

"Can't pick it out? Or don't you know?" Seeing that Gretel was surprised, but he didn't do anything, Lynn simply introduced him:
"This ring should have a [cold and heat resistance], it is very useful, I already have one, you can take this;
I don't know this talisman, but looking at the spell circuit above, it should be an attack spell, you can try it;
This necklace has light power, I can't use it, but you should be able to..."

It was too late for Gretel to refuse.Just as he was thinking of taking whatever he wanted, even if he had accepted the other party's favor, he glanced at the pile of things, and his heart suddenly jumped:
"Wait!—what is this?"

"This?" Lynn looked along his fingertips, and saw that it was a bottle of inconspicuous purple-black powder, flickering slightly under the candlelight, reflecting a bit of scaly metallic luster.He said indifferently:
"Purple scale stone, a kind of alchemy material. I don't know how it got mixed in - this thing is useless, and it's not easy to put away. It turns into a ball of black ash. Are you interested? If you want it, just do it." take it."

"I'll take half." Gretel picked it up like a baby, looking left and right.The color, shape, luster, everything is familiar to him, from junior high school to university.When he saw this thing, his intuition was shouting four words:
"Potassium permanganate! Potassium permanganate!!!"

This thing is not stable in nature, it is easy to decompose, and it is unknown which great god synthesized it.If it is really potassium permanganate, it can be regarded as solving a big problem for him.

Gretel asked Lynn for a brown bottle, carefully poured half of it in, corked the bottle and handed it back.Seeing that Lynn didn't answer, he forced it into his hands:
"This thing is useful! If it is what I think, it will definitely be of great use! Hey, come with me, and when I verify it, I will tell you how to use it!"

Lin En followed him out suspiciously, and walked back to Gretel's own residence in a winding way.Gretel cleaned up the table, dragged out the alchemy box, turned around, saw Lynn sitting there bored, and simply stuffed a stack of papers into his hand:
"This is my latest research result. Look at it first. By the way, you can play with the microscope first. Wait for me to do the experiment! I will call you when I have the result!"

Lin En was caught off guard, and was stuffed with a lot of articles, and all the topics he hadn't seen before.Before he could take a closer look, he raised his head and shouted:
"Have you sent it yet?"

"Some have posted, some haven't! Look first!"

Gretel was busy installing racks, alcohol lamps, and various test tubes and flasks without looking back.Lynn couldn't call him back, so he could only read from the first article "Several Records of Observing Cork, Onion, Meat and Blood Using a Self-made Microscope".As I read it, it was like a mouse fell into a rice vat, and I couldn't even hear Gretel humming.

Gretel was indeed humming.Potassium permanganate was heated and decomposed to produce oxygen. He did it when he was in middle school, but the details need to be carefully recalled.And remembering this kind of thing, instead of endorsing it, it is better to hum a song:

"56 ethnic groups, increase the valence~~~" Wrong, I sang the wrong words, start again;

"56 elements, increase the valence," put down the bracket;
"Brothers and sisters of the 56 ethnic group are oxidized", put down the alcohol lamp, and find something to raise it;
"56 kinds of acids and bases, merged into one sentence," put the sink on the other side of the bracket;
"Potassium permanganate, potassium permanganate, potassium permanganate!" Fill the gas bottle with water upside down and put it in the sink.

Well, it's time to heat up.Gretel hummed more and more happily, with a slightly higher pitch:
"High~~~ Potassium manganate, the method of making oxygen," scooped up a little potassium permanganate powder, put it into a test tube, plugged it with a cork and a glass catheter;
"High~~~ Potassium manganate, heat the fortress cotton," remember, remember, put the cotton in first;
"High~~~ Potassium manganate, the test tube is slightly downward," no problem, just adjust the angle and fix it on the test tube rack;

"High~~~ Potassium manganate, don't touch the test tube with your hands when doing the experiment, or the skin will be oxidized!"

Oops, I didn't remember until I hummed this sentence!I just took the test tube with my hand...on the hand...on the skin of the hand...touched a little potassium permanganate powder!Flush! ! ! !

Gretel frantically rinsed his fingers.Fortunately, everything went well in the subsequent experiments, and the gas gushed out of the catheter, and the bottle was full in a short time.Gretel ignited a small wooden stick, flung it until there was only a little spark left at the top, held his breath, and poked the mouth of the gas bottle:
The fire is bright!

Pure oxygen!

"yeah!"

Gretel cheered.The necromancer raised his head blankly, Gretel waved to him with a smile, took another pinch of potassium permanganate powder, and put it into the test tube.Holding the test tube in his hand, holding his breath, he sketched the spell model in meditation——

In every fire magic, there are two basic configurations: one is used to gather "phlogiston", and the other is used to screen "good air" that can attract phlogiston.

After his modification, the configuration that screens the air points to the test tube, and at the same time adds a slightly magical configuration to heat the test tube to a certain temperature.Hey, when he improved this magic before, he used mercury oxide to heat to produce oxygen, which consumed a lot of energy and took a long time.Fortunately, he found potassium permanganate!

three!
two!
One!

Sparks!
let's go!

It exploded with a crackle.The subtle spark technique, which could only ignite paper and dead leaves, exploded on the muddy ground in the center of the tent, sparks that were much brighter than before!

The spark even alarmed the Necromancer.Lynn looked up from the paper, looked at Gretel, and asked him what happened.Gretel came over with a happy smile:

"I've improved a magic! Let me tell you! —Hey, read the article "Proving the Essence of Combustion Using Heated Mercury" first! Look! Look! After reading it, I'll tell you how to use magic!"

Eating papers, watching experiments, and then looking at the spell model diagram drawn by Gretel, trying to memorize and meditate.The spell model is not difficult for Mage Lin En, but it is too difficult to understand this paper, understand the principle of burning, and then use the principle to achieve new spell ideas.Gretel was experimenting and explaining again, and when his saliva was exhausted, Lynn finally understood a little bit.

More than an hour later, the two mages were carried by the barbarians one by one, slipped out of the barracks like the wind, and went to a far distance outside the camp to experiment with magic.

Sparks!
Extremely bright sparks.

Burning hands!

Blazing white, far more intense cone of fire.

Blazing ball!

The burning fireball flew far away, and the power of the explosion caught up with the higher-level fireball technique!
Master Lynn stared at the fireball, dumbfounded.When he was finally able to speak, every syllable of his trembled slightly:

"Gretel, you...do you know what you gave me?!"

(Remember to order dubbing and listen to songs in this chapter)
　Thanks to @lof雪羽 for rewarding 200 starting coins

　　Please listen to this chapter in conjunction with Station B's "Song of Potassium Permanganate", which is more interesting.

　　I remember it was Luo Tianyi's version
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(End of this chapter)