With the advancement of technology, the cost of mirrors has declined, and the emergence of various curved mirrors has made mirrors more and more widely used, with more uses other than illuminating appearance. For example, the spherical rear-view parabolic mirror used in automobiles, the parabolic mirror used for collection in telescopes and the parabolic mirror used to reflect parallel light in searchlights, etc. Modern mirrors are made by a method created by the German chemist Liebig in 1835. Silver nitrate is mixed with a reducing agent, so that silver nitrate separates silver and attaches to the glass. Commonly used reducing agents are sugar or potassium sodium tartrate tetrahydrate. In 1929, a friend of Pilton in England improved this method with successive techniques of silver-plating, copper-plating, painting, and drying.




According to legend, the first mirror used by human beings was discovered and manufactured by the mother-in-law. At that time, people in the Yellow Emperor Palace often stood by the water and irradiated their faces, dressing up and dressing up. The mother-in-law felt that she was ugly, so it was easy not to go to the waterside to dress up and dress up, and she would not appear at will during festivals. All day long, he only knew how to work beside the Yellow Emperor. Once, the Tongyu clan asked her mother to go up the mountain with her to dig slate. The mother did not say a word and went up the mountain with the Tongyu clan. The mother-in-law has great strength and digs slate faster than other women. In less than half a sound, more than twenty pieces were dug. At this time, the sun is reasonable noon, and the sun shines on the earth. The mother-in-law suddenly discovered that there was a bright stone flake in the pile of stones, and the sunlight was very dazzling. The mother-in-law bent down and dug it out of the ground quietly with her hands. When she saw it in her hand, she couldn't help but startled. What kind of monster is this, and its ugly face is all reflected on this piece of stone. Even she thought it was weird! She quietly hid this piece of stone on her body and went back to the Yellow Emperor Palace without telling anyone about it. Taking advantage of no one around, she took out the stone chips and found that the planes of the stone chips were uneven. The face reflected on it was oddly shaped. The mother went to the workshop where stone knives and axes were made, and found a grinding stone, pressed the stone piece on it and rubbed it repeatedly. She used it to take a photo, it was much clearer than before. Only his appearance is still so ugly. She grinded it for a while, picked it up and took another picture, she was still ugly. The mother-in-law murmured and sighed: "It seems that the ugly face cannot be blamed on the stone flakes (mirror)." From then on, the mother-in-law never went to the river or the water to dress up. Every morning I get up, look at the stone pieces, pick up and dress myself up, and then hide it quietly after use. After a long time, the grandmother became careless. Once the mother-in-law assisted the Tongyu clan to cook meat on the slate. Due to the excessive firepower, the slate was burned and exploded, and a piece of gravel flew up, breaking the mother's face, and the blood flowed non-stop. The mother hurried back, took out the stone tablet, and applied the medicine to her face. Unexpectedly, Huangdi did not know when to come back, and walked lightly to the death of the mother, and found that the mother was holding something in one hand and looking at him, and applying medicine to her face with the other. After Huang Di walked towards the death of his mother, his head was close to the arm of his mother. Just as he was about to look closely, the mother exclaimed! She found that the face of the Yellow Emperor appeared on the stone. Turning her head, she realized that Huang Di was standing behind her death. Huangdi asked his mother, "What are you holding in your hand?" The honest and honest mother, upon hearing Huangdi's question, knew that this matter must not deceive Huangdi, and knelt down in front of Huangdi with a puff. The mother-in-law told the Yellow Emperor from the beginning to the end of the discovery of this piece of stone that could illuminate a human being, and begged the Yellow Emperor to forgive her. After hearing this, Huang Di laughed, put his mother in his arms and said, "This is a great discovery for you. You are not only right, but you have also made a great contribution!" Yu Shi, take out the piece of stone that can see the face of the mother, and tell her three wives to be smart. Lei Zu smiled and said, "Huang Di, no wonder I haven't seen my mother-in-law go to the water to dress up for a long time. She originally had this treasure." Tongyu continued: "Huangdi, this discovery should be given to the mother-in-law's little sister. One credit!" Huang Di said excitedly: "Of course one credit!"