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

Zhang Mu was lying on the bed with his pig head gas mask, holding a bronze mirror. Qiaoer came in and saw this scene. She was laughing so hard that her branches were trembling, leaning forward and backward.

"Why are you laughing? If you smile, be careful to laugh out loud with another front tooth." Zhang Mu said angrily.

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

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

Stearic acid can be made with hydrochloric acid and saponified fat, and white wax can be made into economical candles.

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

Zhang Mu saw that she was wearing a short jacket with Duan Qing today, with an exquisite light green silk horse-faced skirt underneath, a light-colored waist-length armor on the outside, her long black hair was combed with two small braids, and a red-headed rope.

On her fair face, there was a hint of redness, a little baby fat, a slightly raised nose, slender eyelashes, and a pair of big watery eyes. Inside her sapphire-like eyes, clear and quiet, and a cute little girl with pink makeup and jade makeup is really loved by everyone.

"It's no longer painful. What good food to eat at noon? I'll let the kitchen make it for you." Zhang Mu smiled.

"Your family is either chicken, duck or fish, and everyone else has gained weight again." Qiao'er said, then patted his belly, took out a piece of rock candy from his purse on his waist, and fed it to Zhang Mu's mouth.

At this time, Song Wen hurried in and bowed her waist and said, "Young Master, you have ordered all the things you prepared. Should you carry you over?"

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

"No, I have to go too." Only Zhang Mu in the mansion is about the same age as her. Zhang Mu loves her, so he always sticks to Zhang Mu.

"Okay, don't run around after that." After Zhang Mu said that, he asked someone to carry him towards the backyard.

Although Tinghexuan was swept before, the house in the middle was gone, but the wall was still there. During his time in Jinhua Mansion, Zhang Wenguang rebuilt this place and built several small houses, specifically allowing Songwen to make caustic soda and soak the soda.

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

Because the production process is too simple and hydrochloric acid is volatile, some precautions have to be taken.

Zhang Mu lay on the rattan bed outside the house, instructing Songwen to do what he should do.

In later industries, hydrochloric acid was made in the industry, and they were all electrolytic salt water, but there was no electricity, so they could only be heated with sulfuric acid and sea salt.

Without heating or slightly heating, sodium bisulfate and hydrogen chloride were generated respectively, and then the reaction continued to form hydrogen chloride and sodium sulfate under conditions of 500°C to 600°C.

Hydrogen chloride is a gas, and when it is introduced into water, it can become hydrochloric acid.

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

After remembering Song Wen said, "Young Master, I'll go in and try it first, you're waiting here."

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

Songwen nodded and went in.

Zhang Mu and Qiaoer were chatting outside the door.

Candles have existed in China since ancient times. The Song Dynasty recorded that in the border trade with the Western Xia, the transaction items included candles. As a foreign trade and foreign exchange thing, candles showed that although they were used more commonly at that time, they were still relatively precious.

One of the important reasons here is the raw materials for candles.

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

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

Skin oil is not animal fat, but extracted from black sap trees and is vegetable oil, so it is expensive. The candles made are generally unaffordable, and most of them even light oil lamps.

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

Using hydrochloric acid and saponified oil to make stearic acid not only solves the problem of making soap scraps, but also can further reduce the cost of oil and fat through large-scale livestock breeding. Moreover, killing pigs can be sold for money, which is far more cost-effective than the vegetable oils of black squid trees.

In less than half an hour, Songwen came out of the room, held a large porcelain bottle and said, "Young Master, I made some as you told me. What is this thing for?"

"Do you still have any scraps of soap?" Zhang Mu asked.

"Yes, there are so many. I'll get some for you." After saying that, he put down the porcelain bottle and took a wooden basin to pick up a large basin.

Qiao'er looked at the pot of yellow and fatty foam, and hid far away.

Zhang Mu ordered to change the water tank, then pour the hydrochloric acid and scraps together, and wait quietly.

Sure enough, not long after, a thick layer of white frost floated on the water tank, wearing pine patterns and gloves, pinched a little, and walked over to show Zhang Mu.

Zhang Mu crushed it with his hands, it was very smooth and oily, and then he smiled and said, "It's done, go and call the butler."

After a while, Zhang Wenguang hurried over and asked, "Young Master, what are your instructions?"

"Have you bought the model and insect wax you bought?" Zhang Mu asked.

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

Worm wax, also known as ash wax, is a natural wax secreted by worm wax wax. It is cultivated in Sichuan, Yunnan, Huguang, Jiangsu and Zhejiang.

Worm wax can be shaped and mixed with stearic acid to completely replace black oil and make economical and cheap candles.

Zhang Mu asked someone to take cotton thread and wove three into one.

One of the troublesome things about candles used at home is the wick.

Every time it burns for a period of time, it is necessary to cut off some of the wicks. The Tang Dynasty poet Li Shangyin wrote a poem "Why should we cut the candle in the west window together?"

This is because the wick cannot be completely burned, but one of three cotton ropes is braided to loosen naturally when the wick burns, and the end is just to the outside of the flame, so it can be completely burned.

This completely solves the wick problem.

Stearic acid and insect wax were poured into the mold in proportion, and the wick was inserted into the wick. After waiting for about an hour, when the oil solidified, Zhang Mu ordered someone to take off the mold and then lit it with flint.

After a try, the candle was burning, and there was no odor, the flame was strong, and it was very resistant to flames. Zhang Mu looked at the small flame and seemed to hear the sound of copper coins.

A smile cracked at the corner of his mouth and said, "Be the soap king first, then the candle king. Study the matches another day. After that, I will feel sorry for myself if I don't count the money and count my hands until I get cramps."
Chapter completed!