5-Thiazolecarboxaldehyde

Alumite is a mineral, its chemical properties are quite unique, and it has important uses in many fields.
There are many kinds of alum, common ones such as green alum, bile alum, alum, etc., each with its own characteristics. Green alum, that is, ferrous sulfate heptahydrate, has a emerald green color. It is reductive and easy to be oxidized in the air, and its color gradually turns yellow-brown. Gall alum, copper sulfate pentahydrate, is blue in color. Under heating conditions, it will lose crystalline water and change its color from blue to white. This process is a chemical change, reflecting its easy decomposition when heated. Alum, potassium aluminum sulfate dodecahydrate, is a colorless and transparent bulk crystalline or crystalline powder. Its aqueous solution is acidic and can be hydrolyzed in water to form an aluminum hydroxide colloid. This colloid has adsorption properties and can absorb suspended impurities in water, making water clear. Therefore, it is often used as a water purifier.
Alumite also has certain chemical activity. Take alum as an example, it encounters alkali substances and will undergo a chemical reaction. In the case of sodium hydroxide solution, aluminum ions will react with hydroxide ions. According to the amount of hydroxide ions, aluminum hydroxide will precipitate. If there is an excess of hydroxide ions, the precipitation will dissolve and form metaaluminate ions. Furthermore, metal ions in alumite, such as copper ions and iron ions, can participate in the replacement reaction. If iron is placed in a solution of bile alum, the iron will replace copper ions, the color of the solution will fade, and red copper will precipitate, which is the embodiment of the metal activity sequence.
Alumite was valued by alchemists in ancient times and has also been used in traditional medicine. Although its chemical properties are unique, some alumite is toxic, so it needs to be used with caution. When following scientific methods and understanding its characteristics, it can be used well.

The synthesis of Dansha has different ancient techniques. The common ones follow the following methods.
In the past, the Fang family was based on mercury and sulfur. Mercury is white and moist in color, flowing like mercury, and fickle in nature. Sulfur is yellow in color, with a special smell, and strong in nature. When the two meet, they can be used to synthesize Dansha.
Put mercury and sulfur in a special cauldron in a certain ratio. This cauldron must be cast from good materials, can withstand high temperature, and has good sealing properties to prevent drug volatilization. Under the cauldron, the heat is slow to burn. At first, mercury and sulfur seem to be out of phase, each showing its own properties. Then as the temperature rises, the two slowly blend. The warmth of mercury is gradually combined with the intensity of sulfur, like the harmony of yin and yang.
The mastery of the heat is crucial. If the fire is too small, it will be difficult for the two to combine; if the fire is too fierce, the medicine will be easily destroyed. Therefore, the operator needs to focus on the concentration, observe the changes in the cauldron, and adjust the heat in a timely manner. Or first gradually dry the fire to make the breath of the medicine communicate; then turn to the fire to promote the speed of its fusion. Such repeated adjustments, after time, the cauldron gradually changes.
Wait for the color in the cauldron to turn red, and the shape is like red sand, then the image of the completion of the work will gradually appear. However, this fashion needs to be cautious, and it can only be opened when the cauldron cools down. When opening, you also need to be careful, for fear that the synthetic material will change in the wind.
The synthetic dansha obtained may be similar to the natural one, but its physical properties and effects need to be carefully screened by the Fang family. Gaigu's method of synthesizing dansha, although there are common paths, the subtleties are different due to the differences in Fang family's experience and alchemy. This is the accumulation of the ancients' exploration of the synthesis of dansha, and it is also the germ of later chemistry.

"Tiangong Kaiwu" records that arsenic, that is, the letter stone, is a great poison in nature, but it also has its uses in various fields.
In the field of medicine, in ancient times, some doctors used arsenic as medicine in small amounts. According to the "Compendium of Materia Medica", arsenic can eat bad meat, treat malaria, rest diarrhea, etc. In the past, physicians observed the patient's physique and diseases, and used it cautiously to achieve the effect of treating diseases. For example, to treat some sores and swelling toxins, an appropriate amount of arsenic can be used externally, which can kill insects in sores, make bad flesh rot away, and help new muscles grow.
In metallurgy, arsenic has some applications. In the process of lead refining, adding a little arsenic can change some of the characteristics of lead, improve the purity and quality of lead, and make the refined lead more suitable for casting utensils or other uses.
In the agricultural field, arsenic has also been used. In the past, it was found that arsenic has a repellent effect on some pests. Mixing a small amount of arsenic with seeds or sprinkling it on farmland can prevent pests from gnawing on seeds and crops, protect the growth of crops to a certain extent, and reduce the impact of pests on harvest.
Of course, it needs to be clear that arsenic is highly toxic, no matter what field it is used in, it must be used with caution. A little carelessness and improper dosage can cause poisoning and endanger life. Therefore, the ancients used it based on rich experience and strict laws to ensure safety and effectiveness.

In today's world, it is an interesting question to ask what the value of the tortoise shell is. The tortoise shell, used in ancient divination and records, in the past, its value varies according to quality, shape and use.
Looking at the past, the good quality tortoise shell, if it is used by the royal family and aristocratic divination rituals, its price is extraordinary. Gai is priceless because it carries the heavy responsibility of communication between gods and good luck and bad luck. However, ordinary tortoise shells are only used for simple folk divination or memory, and their price is relatively low.
According to ancient books and predecessors, high-quality tortoise shells are worth thousands of gold. Those with thousands of gold were the wealth of great wealth in ancient times, and could be reached by extraordinary people. These tortoise shells must be made of excellent materials, clear texture, and fine production. They are good for divination. Medium tortoise shells, the price may be hundreds of gold, and their quality is also good. They are used by ordinary rich families. As for lower-class tortoise shells, or worth tens of gold, they are mostly used by the common people in the market to ask good or bad.
However, today is different from the past. The use of tortoise shells is no longer used for divination in ancient times. In today's city, tortoise shells are mostly used for collection and decoration. Their price varies with age, preservation, and rarity. Old and well-preserved tortoise shells with unique textures and patterns, if they enter the collection market, may be worth 10,000 gold or even more. The price of turtle shell products produced in ordinary modern times may only range from tens to hundreds of gold, and most of them are handicrafts.
To sum up, the value of the turtle shell market is difficult to generalize, and it depends on a variety of reasons.

There is no specific record of raising cicadas and storing cocoons in "Tiangong Kaiwu", but with reference to content similar to silkworm breeding, it can be speculated that raising cicadas and storing cocoons may have the following conditions:
First, it is necessary to find a suitable habitat. Cicadas like to live in a place with dense trees, and the trees they depend on should be suitable hosts for them. If silkworms rely on mulberry trees for a living, cicadas may prefer specific trees, such as willows, poplars, elms, etc. And this field requires good ventilation and moderate light, not in a dark and humid place, and not exposed to the hot sun for a long time, so as to provide a comfortable living environment for cicadas, which is conducive to their growth and cocooning.
Second, pay attention to the food supply. Cicadas feed on the sap of trees, and the selected trees need to be rich in sap If the tree lacks nutrients and vitality, the cicada may not be able to absorb sufficient nutrients, which will affect the growth and development, resulting in poor cocooning quality. Therefore, it is necessary to take care of the host tree every day, water and fertilize it in a timely manner to ensure its thriving growth and provide a stable food source for the cicada.
Third, control the temperature and humidity. The growth and cocooning of cicadas have strict requirements on temperature and humidity. If the temperature is too high, the cicada is prone to restlessness, excessive metabolism, or early exhaustion of physical strength; if the temperature is too low, its movement is slow and growth is stagnant. Humidity is also critical. If the humidity is too high, the cocoon is easy to mildew; if the humidity is too small, the cocoon quality is easy to dry and hard, which affects the survival and eclosion of the cicada pupa. In general, the temperature should be maintained between 20 and 30 degrees Celsius, and the humidity should be maintained at 60% to 80%.
Fourth, to prevent the invasion of pests and diseases. In nature, cicadas face many threats of pests and diseases. For example, some parasitic insects will parasitize on the cicada body, causing its death; fungi, bacteria and other microorganisms may also cause cicada diseases. Therefore, during the breeding process, the growth of cicadas should be closely observed, and measures should be taken immediately once signs of pests and diseases are found. Physical, biological or chemical methods can be used to control, but chemical control needs to be careful to avoid damage to the cicada body.