"Muguoguo, what are you going to do?" Qiao'er jumped into Zhang Mu's room with the corner of her skirt.

Zhang Mu was wearing his pig-head gas mask, lying on the bed with a bronze mirror, Qiao'er came in and saw this scene, and the flowers and branches of laughter trembled at the moment, leaning forward and closing back.

"Laughing at what? Laugh again, be careful to laugh off the other front tooth as well. Zhang Mu said angrily.

Qiao'er hurriedly covered her mouth, looked at Zhang Mu curiously and asked, "What are you doing wearing this thing on a hot day?" ”

"Of course it's useful." Zhang Mu said, thinking about how to use sulfuric acid and sea salt to make hydrochloric acid.

With hydrochloric acid and saponified fat, stearic acid can be made, and white wax can be added to make affordable candles.

"Does your back still hurt?" Qiao'er curiously lifted the shirt covering Zhang Mu's back, only glanced at it, and the little girl hurriedly let go in fright.

Zhang Mu saw that she was wearing a short jacket with a light green silk horse face skirt underneath, covered with a light-colored waist-length armor, long black hair combed with two small braids, and tied with a red head rope.

On the fair face, there is a touch of redness, a little baby fat, Qiong's nose is slightly upturned, the eyelashes are long, a pair of watery eyes, sapphire-like eyes, clear and quiet, a cute little girl with pink makeup, is really loved by everyone.

"It's been a long time since it hurts, what do you want to eat at noon? I'll let the kitchen do it for you. Zhang Mu said with a smile.

"Your family is either chickens, ducks or fish, and everyone who eats them is fat again." Qiao'er patted his little belly as she spoke, took out a rock candy from the purse on her waist, and fed it to Zhang Mu's mouth.

At this time, Songwen hurriedly came in and bowed his waist and said, "Young Master, you ordered that all the things prepared are ready." Do I want to carry you over? ”

"Qiao'er, you go play with Yan Guoguo first, and I'll go to the backyard." Zhang Mu said with a smile.

"No, people are going too." Only Zhang Mu is the same age as her in the house, and Zhang Mu loves her, so she usually sticks to Zhang Mu.

"Okay, don't run around when you go for a while." After Zhang Mu finished speaking, he asked people to carry him towards the backyard.

Although the previous Tinghexuan was swept away, the middle room is gone, but the wall is still there, during his time in Jinhua Mansion, Zhang Wenguang rebuilt this place, built a few huts, and specially let Songwen do caustic soda and bubble alkali here.

When he arrived at the place, Zhang Mu asked Songwen to put on a mask, put on a cotton suit, and wrapped it tightly.

Because the production process is too simple, hydrochloric acid volatilization is toxic, so some precautions have to be taken.

Zhang Mu lay on the rattan bed outside the house, and told Songwen what to do one by one.

In later generations, the industry made hydrochloric acid, all of which were electrolyzed brine, but there was no electricity, and it could only be heated with sulfuric acid and sea salt.

Without heating or slightly heating, sodium bisulfate and hydrogen chloride are generated, respectively, and then under the conditions of 500C to 600C, the reaction continues to produce hydrogen chloride and sodium sulfate.

Hydrogen chloride is a gas that can be introduced into water to become hydrochloric acid.

The concentration of hydrochloric acid is only more than 30 degrees, so there is no need to make sulfuric acid like blue alum, and there is no need to purify it.

Songwen remembered it and said, "Young Master, I'll try it first, you wait here." ”

"Be careful, if you feel uncomfortable in your eyes, come out quickly." Zhang Mu said.

Songwen nodded and went inside.

Zhang Mu and Qiao'er were laughing and chatting outside the door.

Candles have existed in China since ancient times, and the Song Dynasty recorded that in the border trade with Western Xia at that time, there were candles for trading supplies. As a kind of thing for foreign trade and foreign exchange, candles show that although they were more common at that time, they were still relatively precious.

One of the most important reasons for this is the raw material of the candle.

Modern candles use paraffin wax as the main burning material, and paraffin wax is extracted from petroleum, which is very cheap.

However, in ancient times, the main material of candles was made of leather oil.

Skin oil is not animal fat, but extracted from the black tree tree, is a vegetable oil, so the price is expensive, and the candles made by ordinary people cannot afford to consume, and most of them also light oil lamps.

Moreover, now that the farming technology is backward, and there are no high-yield crops of potatoes and corn, the grain output cannot be increased, and it is not a long-term strategy to plant black trees on a large scale and compete with the people for food rations.

The use of hydrochloric acid and saponified grease to make stearic acid not only solves the problem of making soap scraps, but also further reduces the cost of oil through large-scale animal husbandry, and can sell for money when killing pigs, which is far more cost-effective than the vegetable oil of the black tree tree.

In less than half an hour, Songwen came out of the room, hugged a large porcelain vase and said, "Young master, I have made some according to your instructions." What is this thing for? ”

"Do you have any leftovers for soap?" Zhang Mu asked.

"Yes, a lot. I'll go get you some. After saying that, he put down the porcelain vase, took a wooden basin and fetched a large one.

Qiao'er looked at the pot of yellowing and fat foam, and hid away at the moment.

Zhang Mu ordered the water tank to be replaced, then poured hydrochloric acid and leftovers together, and waited quietly.

Sure enough, it didn't take long for a thick layer of hoarfrost to float on the water tank, and Songwen wore gloves, pinched a little, and walked over to show Zhang Mu.

Zhang Mu rubbed it with his hand, it was very slippery and oily, so he smiled and said, "It's done, go and call the housekeeper." ”

After a while, Zhang Wenguang hurriedly came over, bowed his waist and asked, "Young Master, what are your orders?" ”

"Did you buy the model and wormwax that you bought?" Zhang Mu asked.

"I'll pick it up." At that moment, Zhang Wenguang hurriedly sent someone to get it.

Insect wax, also known as white wax, is a kind of natural wax secreted by ash insects, which is cultivated in Sichuan, Yunnan, Huguang, Jiangsu and Zhejiang.

Insect wax can be shaped, mixed with stearic acid, and can completely replace black tree oil to make an economical and cheap candle.

Zhang Mu asked people to take cotton threads and weave them into one.

There is a very troublesome thing about candles at home, that is, the wick.

Every time it burns for a period of time, it is necessary to cut off a part of the wick, and the Tang Dynasty poet Li Shangyin has a poem "How to cut the candles in the west window".

This is because the wick does not burn completely, but the three cotton ropes are braided so that the wick will naturally loosen when it burns, and the end is just on the outside of the flame, so that it can burn completely.

In this way, the wick problem is completely solved.

The stearic acid and insect wax were poured into the mold according to the proportion, passed into the wick, and waited for about an hour, waiting for the grease to solidify, Zhang Mu ordered someone to demold, and then lit it with flint himself.

A successful try, the candle burns, and there is no peculiar smell, the flame is vigorous, and it is very flame-resistant, Zhang Mu looked at the small flame, as if he heard the sound of copper coins.

The corners of his mouth cracked into a smile and said, "Be a soap king first, and then a candle king." Study the matches another day, and after that, if you don't count the money until your hands cramp, you'll be sorry for yourself. ”

When he was proud, he suddenly heard a small guy outside the door hurrying over, and bowed his waist and shouted: "Young master, there are many people outside the door, saying that the emperor's holy decree is coming." I'm going to get you!"