pyridine-3-ol

Those who come to them mainly use tools made of gold, stone, earth, and wood, as well as methods of carving and making, to worship God.
The ancient people wanted to make tools for the benefit of the world, but they did not know the nature of materials and the method of workmanship, so that the work was completed. Those who come to them can know the nature of gold, stone, earth, and wood, and the method of carving and making, so that the tools made are durable and beneficial to the people's livelihood. Such as tools and ploughs make it easier to plow; the axes and axes of craftsmen help to make things.

The ancient people believed in God, so that all things in heaven and earth had the priests of gods. Those who come to them make sacrificial utensils according to them, so that the gods can be made. The system of sacrificial utensils is exquisitely studied to show respect. In the matter of sacrifice, it is important to offer sacrifices and prosperity, to pray for God's blessing, and to ensure the safety of the people.
It is a matter of great importance to the people. Those who pay attention to it, make the sky, and miss the engraving, and use the sky to do it, and determine the four. The people follow the farming and harvesting, and the family also arranges decrees and ceremonies for this.
It is, to those who pay attention to it, to their skills, to make tools for the convenience of the people, to pay tribute to the gods, to benefit the image, to those who are indispensable in the ancient times, and their merits will benefit the world.

Of the three things that are burnt, there is a kind of nature. This burnt thing is something that is incinerated by fire, and it has dryness. The fire, the burnt thing is also, when the burnt thing encounters fire, its nature is dry. When it is burnt by fire, the water is lost, and then it dries up and cracks, and it is dry.
And it has nature. On the heat of the fire, the burnt thing is burnt. When it is burnt, it is scattered all around. This nature does not exist in the burning of the burnt thing, even if the fire is extinguished, it will remain. Burnt with firewood, the firewood ash has a quality, and it can be written by its nature.
Furthermore, it has chemical nature. Burnt, the biochemical of the thing. Such as wood, burnt to form charcoal, its shape and properties are all before. The original wood is soft and foldable, burnt to form charcoal, hard and has the characteristics of adsorption. It is also like gold, when it encounters high burnt, it can be melted into liquid, and cold to form a new form. This is the appearance of all properties.
And it is the power of burnt. It can be made into a shape. It is not grass, wood, earth and stone, or silk and gold, burnt for a long time, or ash, or melted. In the past, the A-fang was a big one, and the fire of a feather was burnt, and it was also burned, and it was only a wall. This is a great example of the nature.
In addition, to the three burnt things, the physical properties of dryness, transformation, and transformation are special, and the power of fire can be used to transform things.

Mercury is strong and toxic. It is one of the metal elements. It is liquid at room temperature and pressure. It has a metallic luster and is also the only liquid metal. Its many chemical properties are very unique.
Mercury has high chemical activity and is easy to react with a variety of substances. When exposed to oxygen, it can form mercury oxide when heated, which is a common chemical change. When mixed with sulfur, the two can quickly combine to form mercury sulfide. This property is often used to treat mercury leakage to reduce its toxicity and diffusion.
Furthermore, mercury can form amalgam with many metals, which is quite amazing. The formation of amalgam allows mercury to fuse with other metals, changing its physical and chemical properties, and has many applications in metallurgy and other fields.
However, the toxicity of mercury should not be underestimated. Its vapors and compounds are highly toxic, and if inhaled or exposed to the human body, it will cause serious damage to the nervous system, kidneys, etc. Although the ancients did not know the detailed principle of its harm, they were also aware of the danger of mercury in long-term practice.
The chemical properties of mercury not only give it unique uses, but also because of its toxicity. It should be used and disposed of with extreme caution. It must not be negligent due to its characteristics and cause harm.

The method of making arrows from it is described in detail in "Tiangong Kaiwu".
At the beginning of making arrows, the selection of materials is important. The material of the arrow shaft is mostly bamboo and wood. Bamboo, because of its tough texture, light and good elasticity, is often the first choice. However, bamboo is also different. It should be chosen with a straight texture and a uniform internode. Wood is suitable for birch, willow, etc., which are dense and not easy to fold.
When making arrows, first cut the arrow shaft. The craftsman uses a sharp knife to cut the bamboo or wood to a uniform thickness and length. Its length varies according to the bow and crossbow of the arrow, usually several feet. The straightness of the arrow shaft is related to the flight trajectory of the arrow, so it must be straight and uncurved. The craftsman used vision and hand stroking to repeatedly calibrate it.
The second time is to install arrowheads. There are many types of arrowheads, such as willow leaf arrowheads, three-pronged arrowheads, etc. The arrowheads are mostly cast in iron, and the heat needs to be appropriate when casting, so that the texture of the iron is firm. After casting, polish it with a thin file to make it extremely sharp. Then tie the arrowhead firmly to the front end of the arrow shaft with glue or string.
Furthermore, it is the clothing of arrow feathers. Arrow feathers in the flight of arrows have the effect of guiding and stabilizing. Feathers are mostly taken from birds, such as carved feathers and geese feathers. When choosing feathers, Arrange the feathers neatly and glue them on the back end of the arrow shaft. The position and angle of the paste are determined to ensure that the arrow can maintain balance during flight and hit the target accurately.
And the process of making arrows, striving for excellence, the slightest difference may cause the performance of the arrow to be very different. Therefore, the craftsmen are all attentive and meticulous in the selection of materials, cutting rods, installing arrowheads, and sticking feathers, so that they can get good arrows for hunting and warfare.

When hiding and using ice, there are many things to pay attention to.
When hiding ice, the first choice of ice source. When choosing clean and unstained water sources, such as clear springs in deep mountains and valleys, clear lakes, etc. The water source is pure, so as to ensure the quality of the ice for subsequent use. Furthermore, the ice must be carefully constructed. It should be selected in a cool and deep place, such as cellars and ice cellars, and it must have good sealing and heat insulation. In this way, the ice can be hidden for a long time and its cold nature can be preserved.
When using ice, there are also many precautions. First, the occasion for using ice needs to be appropriate. When it is used to cool off in midsummer or to preserve fresh delicacies and delicacies, ice can play an important role. However, use ice should not be excessive, so as not to hurt the yang energy of the human body. Second, use the method of ice should be appropriate. If you use ice to cool down, you can place ice in a container and place it in an appropriate position indoors, so that it melts and absorbs heat to make the room cool. However, the ice should not be placed too close to people to prevent the cold from invading the body.
Furthermore, the use of ice should follow the season and etiquette. In ancient times, ice was a precious thing and was not commonly available. Therefore, when using ice, it was often based on status and season celebrations. For example, during major sacrifices and festivals, there were strict etiquette for offering ice to gods and entertaining guests. Improper use of ice, or poor courtesy, is criticized.
In short, both ice storage and ice use require careful attention to the selection of ice sources, ice storage places, ice use occasions, methods and courtesies, etc., in order to make the best use of ice, and in accordance with the rules, it is beneficial to people.