1,2-Benzothiazole-3-ketone

Mercury is also a toxic substance, and its main use is quite complicated. In ancient times, mercury was often used in the refining of alchemy pills. At that time, alchemists wanted the elixir of immortality, using mercury and other substances as raw materials, hoping to refine miraculous pills for emperors and generals to take, and achieve the dream of prolonging life and becoming immortals.
In the field of medicine, mercury has also been used. According to ancient medical records, mercury and mercury compounds can be used in medicine to treat scabies, acne and other diseases. At that time, the understanding was limited, and the toxic hazards of mercury were not known. Accidental use of mercury can easily cause mercury poisoning and harm human health.
Furthermore, mercury has its uses in the metallurgical industry. Because mercury can form amalgam with many metals, it can help to refine precious metals such as gold and silver. With the characteristics of amalgam, impurities are separated, metals are enriched, and the purpose of purification is achieved.
In ancient decoration and handicraft production, mercury also has traces. For example, the gilding process requires mercury to participate. Mercury and gold are made into gold amalgam, coated on the surface of the utensils, heated to evaporate the mercury, and the gold is left in the utensils to form a bright gilt effect, making the utensils more luxurious.
Of course, it needs to be clear that mercury is very toxic and can damage the human nervous system, kidneys, etc. Although it has many uses in ancient times, its harm cannot be ignored. With the development of the times and the progress of cognition, the use of mercury has now been strictly controlled in order to reduce its damage to the environment and people.

Mercury is a metallic element with the symbol Hg, formerly known as mercury. It has the following physical properties:
First, at room temperature, mercury is in a liquid state, which is its remarkable characteristic. Most metals are solid, but mercury exists in a liquid state at room temperature. For example, all kinds of metals mentioned in "Tiangong Kaiwu" are rare to see such a property. Its fluidity is quite good, like a smart water, it can roll freely on a plane.
Second, the color of mercury is silver-white and bright, reflecting light like a mirror, shining brightly, which is very eye-catching, and it is easy to attract attention from a distance.
Third, the density of mercury is quite high, reaching 13.59 grams/cubic centimeter. Compared with common metals, such as iron, the density of 7.86 grams/cubic centimeter, mercury is heavier. If the same volume of mercury and iron is placed in the hand, the weight of mercury can be clearly sensed.
Fourth, the melting point of mercury is extremely low, -38.87 ° C, and it can reach its melting point and liquefy in a normal low temperature environment. In contrast, the boiling point is 356.6 ° C, which requires a large temperature span to convert from liquid to gas.
Fifth, mercury has good thermal and electrical conductivity. Although it is not as excellent as metals such as silver and copper in terms of thermal conductivity, it still has a certain level and can play a corresponding role in many fields.
Sixth, mercury has a high surface tension. When it drops on a flat surface, it will gather into nearly spherical droplets, which are like round beads and are not easy to disperse.

Mercury is a chemical substance. Its properties are special. Under normal temperature and pressure, it is a liquid metal and has considerable fluidity. In terms of its chemical properties, it is relatively stable, but it is not completely stable.
Although mercury is more stable than many active metals, it is not easy to undergo drastic changes such as replacement reactions with common acids. When it encounters strong oxidants, mercury will also chemically react with it. In case of concentrated nitric acid, mercury can react with it to form products such as mercury nitrate. This reaction shows that the chemical properties of mercury will change under specific conditions, and it is not absolutely stable.
And mercury in the air, although it reacts very slowly at room temperature, if heated, will combine with oxygen to form mercury oxide. This phenomenon also shows that the chemical properties of mercury are not static and stable.
Furthermore, mercury can form amalgam with a variety of metals. Although this process is not a typical chemical reaction, it reflects the physical and chemical activity of mercury. It can interact with other metals to form new forms of matter.
In summary, the chemical properties of mercury seem to be stable under normal circumstances, but under certain conditions, such as the presence of strong oxidizing agents, heating, etc., chemical reactions also occur, not absolutely stable. Its stability depends on the specific environment and reaction conditions, and it cannot be generalized that its chemical properties are completely stable.

There are various methods for the synthesis of mercury. One is the method of smelting Dan sand. For Dan sand, mercury sulfide is also used. When smelting, mercury can be precipitated. "Baopuzi Inner Chapter" states: "Dan sand is burned into mercury, and the accumulation changes into Dan sand." As mentioned in this, first put Dan sand in the furnace tripod, heat it with charcoal fire, reach an appropriate temperature, decompose Dan sand, mercury is turned into vapor and escapes, and mercury can be collected by condensation to obtain mercury.
The second is the method of smelting mercury ore with other substances. For example, mercury ore and iron and other metals are co-located in the furnace, and after high temperature smelting, a replacement reaction occurs. Iron is more active than mercury, and can replace mercury from its ore.
Third, in ancient times, mercury was also obtained by wet method. In the solution of mercury-containing compounds, specific substances were added to make mercury ions precipitate or reduce, so as to obtain mercury. This requires a deep understanding of the properties of various substances and a good control of the reaction conditions to be successful.
However, no matter what method, mercury is highly toxic, and extreme caution is required when synthesizing and using it. Although the ancients knew the method of synthesis, the operation process was often caused by poor protection, which caused mercury poisoning. And the synthesis of mercury was mostly used for alchemy, pharmaceuticals and other purposes. Under the level of cognition at that time, its harm was often ignored, which is a big pity.

"Tiangong Kaiwu" states that alum is an important item, and the price varies from time to time and from quality to quality in the market. It has a wide range of uses and is indispensable in dyeing workshops, metallurgy and many other industries, so its price is also affected by supply and demand.
Common alum, such as alum, green alum, etc. Alum is mostly used in water purification, medicine and food processing, etc. Green alum is commonly used in agricultural fertilization, pigment preparation and other fields. In the past market, if the output of alum was abundant and the supply exceeded the demand, its price would decrease; in case of natural disasters or changes in the origin, the output would drop sharply, and the supply would exceed the demand, and the price would rise.
Generally speaking, the price of alum of ordinary quality is between a few and dozens of copper coins per catty on average days. However, if it is refined and high-quality alum, used in fine craftsmanship or special pharmaceutical production, the price may reach more than 100 copper coins per catty. In prosperous cities, due to the concentration of merchants, the demand is strong, and the price of alum may be slightly higher in remote places. And near the origin, due to the convenience of transportation and sufficient supply, the price may be relatively low.
The price of alum often fluctuates due to factors such as age, origin, quality, and market demand, and it is difficult to have an exact and constant price range. It depends on the specific situation of the time and place.