Gifts are things that people exchange to express blessings and ideas, or to show friendship in social interaction. Gift is the carrier of the message, emotion and desire that the giver sends to the recipient. It is usually the object that people give each other. The purpose is to please others or show good faith and respect. Gifts are also used to celebrate holidays or important days, such as Valentine's Day roses or birthday gifts, and should not be sent. Gifts can also be immaterial. In ancient China, there was a famous saying: "go out of the goose thousand miles, emphasize lightness and emotion". The value of a gift lies in the goodwill and ideas of the giver, not the value of the gift itself. Gifts don't need to be too expensive, as long as they express their intentions.

    Three hundred years ago, glass mirrors were born. Put a shiny foil on the glass and pour in mercury. Mercury is a liquid metal that dissolves tin and becomes a thick silver white liquid that is tightly attached to a glass plate. Glass mirrors are a big step forward than copper. It is very popular and it has become a treasure purchased by royal nobles. Only Venice's factories would have produced this new glass mirror at that time. European countries will buy it, and wealth will flow to Venice like tide. The mirror workshop was concentrated on the island of Murano, surrounded and closed by guard posts. The French government later bought four Venetian mirror craftsmen with heavy money and secretly took them out of the country. Since then, the mysterious color of mercury glass mirror has been revealed, and its value is not so noble.

    However, mercury mirrors are not capable of reflecting light. It took time, mercury was toxic, so it was later eliminated. There is now a thin layer of silver on the back of the mirror. This layer of silver is not coated or electroplated. It is coated with chemical "silver mirror reaction". Add glucose water into the ammonia solution of silver nitrate, which reduces the invisible silver ions to silver particles, deposits them on the glass to make silver mirrors, and finally paints the production line. Seeing this, you will say, "what looks at the back of the mirror is not mercury, but silver."

    This conclusion is lagging behind the times again! In recent years, many of the Department Store mirrors have been backed by aluminum. Aluminum is a kind of silver white shiny metal, much cheaper than precious silver. The manufacturing of aluminum mirror is to evaporate aluminum in vacuum, and the aluminum vapor condenses on the glass surface and becomes the aluminum film layer. This kind of aluminum mirror is cheap and promising. So you'll say, "imagine a small mirror, but it's changing too! There are several chemicals on the back of it. "

    Gifts are produced and developed with a series of other ritual activities. We know that rituals originated from ancient rituals. In worship, people pay homage and awe to God in a standard and devout manner. In addition, they will be dedicated to God as the most valuable and respectful project (i.e. sacrifice).

    Perhaps from that time on, in the sense of ceremony, there began to be material composition and performance. Rituals can appear in the form of objects. As for the concept of gift, it was also said that it originated from the annexation of tribes in the ancient Nagong war, that is, the conquerors often send the conqueror food, slaves and so on to show their obedience to the conqueror. And plead for the asylum of the conqueror.

    Communication and mutual gifts are indispensable to human social life. The Chinese have always advocated reciprocity. "Li Li Song, a rite note," said: "etiquette exchanges will never come, respect, go, or be polite."