2-pyridinecarboxamide, 6-chloro-

"Tiangong Kaiwu" was written in the Ming Dynasty. At that time, the chemical knowledge system was different from that of modern times. However, according to modern chemical knowledge, the answer can be as follows:
"2 - to its carapace, 6 - halogen -" This description is vague, and it is speculated that "carapace" may refer to a container. "Halogen" usually refers to halogen elements, including fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At), etc. If the "halogen" here is chlorine, common chlorine-containing compounds such as sodium chloride (NaCl) have a chemical structure of sodium ion (Na) and chloride ion (Cl) combined by ionic bonds to form an ionic crystal structure. Each sodium ion is surrounded by six chloride ions, and each chloride ion is also surrounded by six sodium ions, which are arranged according to a certain pattern in space.
If it is hydrogen chloride (HCl), in the gaseous state, the hydrogen atom (H) and the chlorine atom (Cl) are connected by covalent bonds, the hydrogen atom provides an electron, and the chlorine atom provides an electron, and the two share the pair of electrons to form a stable structure. When liquid or dissolved in water, HCl will ionize hydrogen ions (H 🥰) and chloride ions (Cl).
Another example is sodium bromide (NaBr). The structure is similar to that of sodium chloride. Sodium ions (Na 🥰) and bromine ions (Br) form ionic crystals through ionic bonds, and the ions are arranged regularly in the lattice.
Due to the limited information given, the possible structure of the compound can only be inferred according to the common situation of "halogen". If more information can be added about the specific reaction and substance referred to by "2-to-its-carboxylic", its chemical structure will be more accurately explored.

Mercury, the ancient name "", also known as "white", "beautiful girl", "pool", "flowing beads", etc., has many special physical properties.
Mercury is liquid under normal conditions, and it is the only liquid gold. This property is very special. Multiple gold is solid under normal conditions, only mercury exists in nature as a liquid. Its liquid properties make it have good fluidity, which can flow like water, and the flow is white light, such as a living river.
The melting temperature of mercury is low, -38.87 ° C, so it is liquid in normal conditions; the boiling temperature is not high, 356.6 ° C. This property makes mercury susceptible to vaporization. In chemical and industrial processes, mercury is often changed due to high temperature.
Mercury has a high density of 13.59 g/cm3, which is higher than that of ordinary liquids. Mercury is placed on top of other liquids and sinks to the bottom due to its high density, just like heavy gold.
The surface force of mercury is large. On the dry plane, mercury droplets can maintain a nearly perfect spherical shape and are not easy to fall off. This property allows mercury to assume a special shape under specific conditions. In the micro-world, the surface of mercury droplets is like a thin film wrapping liquid.
Mercury can dissolve many gold particles to form mercury. Gold, gold, gold, and other gold can all form mercury. The formation of mercury is widely used in metallurgy, dentistry and other fields. In ancient times, people also used mercury to extract gold.

In the context of "Tiangong Kaiwu", the old saying is answered:
If you add two or more, add to the pill furnace, the things involved in this, or the number of supplements for the medicine of alchemy. As for the six subtractive and halogen, halogen is a salt substance, which has a salty and bitter nature, astringent taste and cold nature. Its chemical properties, in metallurgy, can be used as a melting agent, which can reduce the melting point of ore and promote metal separation. For example, in the genus of smelting lead and zinc, halogen is helpful.
In the industry of salt making, halogen is the source material, and it is produced by the method of frying and sun exposure. Halogen contains many kinds of salts such as magnesium, calcium, potassium, etc. It is active in nature and often changes when it encounters other things. In case of lime, precipitation can occur, which is the response between halogen and alkaline earth metal compounds.
And in the process of chemical industry, halogen can be used as a raw material to make many chemicals. When it encounters acid, or raw gas, or into new salts, it changes thousands of times. In the soil of agriculture, if there is too much halogen, it can cause salinity and alkali in the land, which is unfavorable for crops. Because it changes the physical properties of the soil, the fertility is reduced, and the root system is difficult to comfort. Therefore, those who use halogen should review its properties, make the best use of it, and stop it in moderation.

In the world described in "Tiangong Kaiwu", in the field of metallurgical casting, there are many common methods to remove impurities in copper and make copper pure.
When smelting copper, charcoal is often used as fuel. The high temperature generated by the combustion of charcoal can melt the copper ore, and the reductivity of charcoal can reduce the oxides such as copper oxide in the copper ore to copper. During the smelting process, impurities are different from the physical properties such as melting point and density of copper. By skillfully controlling the temperature and smelting time, impurities can float on the copper liquid or sink to the bottom, thereby separating from the copper.
When refining copper, air or oxygen is often bulged into the copper liquid. This is because impurities are more likely to react with oxygen than copper. After air or oxygen is injected, the impurities are preferentially oxidized, and the generated oxides either enter the slag or evaporate, thus improving the purity of copper. Furthermore, some fluxes, such as lime, are used. The flux can chemically react with impurities in copper to generate slag with a lower density and easy to separate from copper. When the slag floats on the surface of the copper liquid, it can be skimmed off to achieve the purpose of removing impurities.
As for the purification of tin, there are also corresponding methods. When heating the tin ore, control the appropriate temperature so that the tin melts first and flows out, while the impurities remain in the slag. This is achieved by the difference in melting point. The resulting tin is then refined, or the method of remelting is used to melt the tin again, and the impurities floating on the surface are removed during the melting process; or by chemical methods, specific reagents are added to remove the impurities and react with them to obtain pure tin.
All these are the methods commonly used in the era of "Tiangong Kaiwu" to remove impurities and improve purity in the process of smelting copper and purifying tin and other metals. This is the condensation of the wisdom of the ancestors, which is of great significance in the development of metal smelting technology at that time.

If you want to make two-dollar realgar and six-dollar mercury medicine, the method is as follows:
Prepare a good weapon first, preferably a copper kettle, which is clean and scale-free, so that the medicine can be free of impurities. The realgar has a toxic sex temperature and is as red as a pill. It is collected from deep mountains. It is necessary to choose a pure one and study it into a fine powder, which is as fine as dust, so that it can be easily combined with other medicines. Mercury, like running beads, is agile and lively. It is not easy to collect. When using it, be careful not to let it scatter.
Place the finished realgar powder at the bottom of the kettle and spread it evenly, about three points thick. Take the mercury for the second time and slowly pour it on the realgar. See the mercury beads rolling among the realgar, and they do not blend. Then, seal it tightly with the lid of the kettle, so that there is no gap, so as to prevent the leakage of the medicine gas.
Place the kettle on the fire, and bake it slowly with a gentle fire at first, so that its medicinal properties gradually increase, and the fire is slightly, like the warm sun in spring, warm but not strong. After a while, the fire will increase slightly, but it should not be too fierce. It is like a summer breeze, and it will slowly warm up, so that the medicine will boil slightly in the kettle. Looking at the essence of the heat, it is all in the eyes and hands. If the fire is too strong, the medicine will be easy to burn; if the fire is too weak, the medicine will be difficult to produce.
Cooking in this way, about two hours, during which you cannot leave without permission. When the heat is enough, turn off the fire and wait for it to cool down. At this time, the medicine in the kettle has changed, and when the kettle is opened, it can be seen that realgar and mercury are integrated, the color is golden, and the texture is warm. This is the medicine made. However, this medicine is toxic, and it should be used with caution. Do not try to take it internally. When following the medical path, external use for treating diseases may exert its effect. When making medicines, you should also pay attention to ventilation to prevent poisonous gas from hurting people.