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Mercury sulfide, known as cinnabar, can be obtained by calcination. Mercury, also known as mercury, is very important in the field of alchemy and medicine.
Mercury in alchemy has its unique nature. The ancients believed that through specific refining methods, mercury and other substances could be used to refine elixirs of immortality. Adhering to the theory of yin and yang and five elements, the alchemists combined mercury with other gold and stone objects, hoping to achieve miraculous transformation of matter in the cauldron furnace and obtain elixirs with extraordinary efficacy. This is the expression of the ancients' eternal pursuit of life and their exploration of the mysteries of material change.
In medicine, mercury and its compounds were also used in ancient formulas. For example, light powder and other mercury-containing drugs, according to ancient records, can be used to treat scabies, syphilis and other diseases. However, at that time, limited awareness was not fully aware of the toxicity of mercury.
And mercury sulfide cinnabar, not only has medicinal value, its bright color also makes it a pigment of choice, used in painting, painting and other processes, adding color to artistic creation. However, cinnabar decomposes mercury after heating. Mercury is a liquid metal at room temperature, which is volatile and toxic. Although the ancients used it, they did not fully understand its harm.
Mercury and related substances played a role in many fields in ancient times. Although the exploration of alchemy for longevity was unsuccessful, it reflected the ancients' unremitting pursuit of natural mysteries; the application of medicine reflects the ancients' attempts to cure diseases and save people, but it is necessary to objectively look at its advantages and disadvantages.

Mercury, commonly known as mercury, is a liquid metal with unique physical properties, which are also reflected in the fields covered in the ancient book "Tiangong Kaiwu".
Mercury is liquid at room temperature and pressure, which is one of its remarkable physical properties. Its fluidity is very good, just like smart water, it can flow freely on the plane, just like all the smart things described in the book, it can move with the heart.
Mercury has a high density, and compared with many common substances, mercury is heavier under the same volume. This property makes it special in some scenarios. If placed in a container, it can be stabilized at the bottom because of its high density, and it is not easy to shake. It is like a solid foundation, laying the foundation for related operations.
Mercury has good electrical conductivity. In circuits and other related fields, its electrical conductivity can be analogous to that of some fast conductors recorded in the book, which can efficiently transfer current, make the circuit run smoothly, and ensure the normal operation of all kinds of electrical equipment.
Mercury has a high surface tension, and its liquid surface is like a tough film, which can keep mercury droplets on a flat surface in a nearly spherical shape, just like a round pearl. This property makes it unique in specific experiments and processes. The melting point of mercury is -38.87 ° C and the boiling point is 356.6 ° C. This range of melting point and boiling point allows mercury to maintain a liquid state at room temperature and transform into a gaseous state at a relatively high temperature. This temperature range characteristic has important application value in many chemical, metallurgical and other fields, just like many materials in "Tiangong Kaiwu", which play a key role in different processes according to their characteristics.

Mercury is a highly toxic substance, and its nature is cunning and changeable. The elemental substance of mercury is liquid at room temperature, with flickering silver light and abnormal agility, which seems to be unruly.
Mercury has strong volatility and can be quietly dispersed in the air. If inhaled inadvertently, it can easily damage the nervous system, kidneys, etc., causing dizziness, fatigue, tremor, or even life-threatening.
The chemical activity of mercury cannot be underestimated. It can combine with oxygen in case of heat to form mercury oxide. And it can form amalgam with many metals. This property is occasionally used in metallurgy and other fields, but it also has hidden risks.
Mercury in acid solutions has different behaviors. In case of nitric acid, it can react violently to form products such as mercury nitrate. In the case of sulfuric acid, hydrochloric acid, etc., the reaction at room temperature is not very obvious.
Mercury ions also have unique chemical properties, and can form precipitation with a variety of anions. If they meet sulfur ions, mercury sulfide is quickly formed. This precipitation is red and stable, and is often cherished by the ancients. It has its presence in alchemy and other techniques. However, because of its toxicity, it must be used with extreme caution. If there is a slight mistake, there will be endless disasters. Between heaven and earth, mercury, with its unique chemical properties, is both wonderful and dangerous. Those who use it should be well aware of its nature and treat it with caution.

To make hydrocyanic acid and sodium cyanide, the ancient method is rare, because both are highly toxic substances, and the operation is careless, and it is dangerous. However, if it is strong, there may have been cyanide-containing ores in the past, which have been roasted and other techniques to precipitate cyanide.
If you use cyanoside-containing plant raw materials such as bitter almonds, through complex processes such as hydrolysis, you may be able to get the clue of hydrocyanic acid. However, this is a dangerous method. There is a slight mistake, and the poisonous gas overflows, hurting people invisibly.
As for sodium cyanide, it may be obtained by neutralizing hydrocyanic acid and sodium hydroxide. But the preparation of both requires extreme caution, and such highly toxic substances are strictly controlled by the law today, and non-professional and qualified people should not act recklessly. In today's world, science and technology are prosperous, and although there are other ways to produce related compounds, they must follow laws and regulations and safety rules. It must not be a temporary desire.

The crystal of the burning sun is called mercury. It is also a thing, and its nature is very spiritual and fickle. When using it, many people should be careful.
Mercury is poisonous, touching the skin and smelling the spirit. Therefore, when using mercury, the first thing to do is to be careful about protection. When wearing a protective clothing, it is advisable to hold a protective gear with your hands, and do not let your skin touch it. And use it in a ventilated place to prevent its gas from accumulating and harming the body. If you didn't notice it in the past, your skin was stained with mercury, and soon, your body was carbuncle, and you were in pain. This is a warning from accidentally touching mercury.
Furthermore, the evaporation of mercury is very fast. In an open device, it dissipates in an instant. It is necessary to use a closed device for the storage of mercury, which is tightly sealed to prevent it from escaping. If mercury escapes in the room, it should be covered with sulfur as soon as possible. Sulfur and mercury, when they meet, can melt, and can prevent its poison. Otherwise, mercury gas will permeate the body, damaging the brain and the organs, and it will be a great disaster.
Also, the chemical properties of mercury are special, and they combine with various things, and there will be many changes. When using it, be clear about its nature, and examine its appropriateness. When it is in harmony with other things, you must carefully study the classics and understand its laws. Don't act rashly, cause unexpected things. The ancient alchemists, who wished for longevity, arbitrarily mixed mercury with various medicines, and refined it into medicinal pills. Those who took it often caused death due to illness. This is all unclear about the nature of mercury, and it is the fault of combined refining.
And the envoy of mercury, when there is a fixed place, do not place it anywhere. Where mercury is placed, it should be far away from water and fire, and avoid dryness and temperature. Fire will promote its volatilization, and water may cause it to disperse. If it is not warm and dry, it can change.
Therefore, the way of mercury is to protect it, be careful when it is used, understand its nature, and follow its laws, so that it can obtain its benefits and avoid its harm.