Arsenic, or arsenic trioxide, is highly toxic. In ancient times, arsenic was often used for punishment, assassination, and medical treatment.
In terms of punishment, its toxicity is violent, it can quickly kill, and it is often used to execute people who have committed the most heinous crimes. There are many records in ancient books, and it is not uncommon to use arsenic to give death. This is to punish criminals by poisoning and demonstrate the majesty of the law.
In terms of assassination, arsenic is colorless, odorless, easy to poison and difficult to detect, so it is often used by those with ulterior motives. In court struggles and disputes in rivers and lakes, there is no shortage of arsenic to assassinate opponents. Because of its rapid toxic onset and serious consequences, it can often achieve the purpose of assassins.
However, arsenic is not entirely evil, and it also has its unique uses in the field of medicine. Ancient healers were well aware of the toxicity of arsenic, but they also skillfully used its characteristics. In the treatment of specific diseases, such as certain sores, tuberculosis, etc., after special processing, the use of arsenic in small doses may have the effect of fighting poison with poison and helping patients relieve pain. This is the delicacy of traditional Chinese medicine.
Of course, it needs to be made clear that arsenic is extremely toxic, and if used carelessly, it will endanger life. Therefore, whether it is in punishment, assassination, or medical application, it needs to be treated with caution. Throughout the ages, the tragedies and stories caused by arsenic have been countless, and they have also warned the world to be in awe of highly toxic things.

In "Tiangang Kaiwu", about the physical properties of pollen-3-alginic alginic acid, its shape is like a paste, its color is brown-yellow, and it looks like the heavy color of autumn wood leaves. It feels smooth and delicate to the touch, and it seems to be slightly moist when placed at the fingertips, but it is not sticky.
Its texture is quite unique, and it has a certain toughness at room temperature. If you apply external force lightly, it can be slightly deformed, but when the external force is removed, it can return to its original shape, just like a spiritual object has nature and knows how to stretch. Its density is slightly heavier than that of water. If it is thrown into water, it will sink to the bottom immediately, and it can slowly stretch in water, just like flowers blooming in water, gradually blending with water, but it is not completely confused, and its existence can still be discerned.
This substance is hygroscopic. In a dry place, it can quietly absorb water vapor in the air, causing its own weight to gradually increase, and its appearance is slightly moist. Its thermal conductivity is not very good. When touched by hand, although the feeling of warmth and coolness changes slightly from time to time, it is like a warm and thick generation, slow and introverted. And it has no significant response in the electric field and magnetic field, as if it is independent of electromagnetic disturbance, and remains silent.
As for its solubility, in some specific organic solutions, it can slowly dissolve and turn into a uniform liquid, but in common aqueous solvents, it can only be partially dissolved, showing a semi-melted state, like looking at flowers through fog, faintly and neatly, it is difficult to fully understand its internal changes. Its physical properties are so complex and wonderful, it is truly a wonder of creation, and it is waiting for the world to explore it in detail to understand its mysteries.

To prepare 4-benzyl-3-furanoic acid, the following methods can be used.
First, use the corresponding halogenated benzyl and furan-3-carboxylic acid derivatives as raw materials. First take furan-3-carboxylic acid and react it with appropriate reagents to convert it into active derivatives, such as making it into an acid chloride. Another halogenated benzyl is taken, and in a suitable solvent, under the action of a base, the two undergo nucleophilic substitution reaction. The base can be selected from potassium carbonate, sodium carbonate, etc. The solvent is dichloromethane, N, N-dimethylformamide. During the reaction, the temperature and reaction time are controlled. After careful operation, the precursor of the target product can be obtained. After appropriate subsequent reactions such as hydrolysis, 4-benzyl-3-furanoic acid can be obtained.
Second, the strategy of building through carbon-carbon bonds. Select compounds containing furan rings and electrophilic reagents containing benzyl structures to react in the presence of suitable catalysts. For example, transition metal catalysts, such as palladium catalysts, are used to catalyze carbon-carbon bond coupling reactions. In the reaction system, ligands are added to enhance the activity and selectivity of the catalyst, and phosphine ligands can be selected for ligands. The reaction needs to be carried out under the protection of inert gas to avoid the deactivation of the catalyst and the occurrence of side reactions. By carefully adjusting the reaction conditions, such as temperature, catalyst dosage, reactant ratio, etc., the precise construction of carbon-carbon bonds is achieved, and then the target product is obtained. Subsequent functional group conversion is necessary to obtain 4-benzyl-3-furanoic acid.
Third, furan and benzylation reagent can also be considered as starting materials, and the furan can be benzylated first. The benzylation reagent can be selected from benzyl halide or benzyl alcohol. Under the action of acidic catalyst or basic catalyst, the specific position of the furan can be benzylated. If you use acidic catalysts, such as concentrated sulfuric acid, p-toluenesulfonic acid, etc., you need to pay attention to the selectivity of the reaction, because acidic conditions may initiate side reactions such as ring opening of the furan ring. If you use basic catalysts, you need to control their basic strength and reaction conditions to ensure the smooth progress of the benzylation reaction. After obtaining the benzylated furan product, a carboxyl group is introduced into the appropriate position of the furan ring through oxidation and other steps to obtain 4-benzyl-3-furanoic acid. During the operation, each step needs to be carefully controlled to improve the purity and yield of the product.

Cyanoacetic acid needs to be paid attention to when it is stored and stored.
Cyanoacetic acid is extremely toxic.
Cyanoacetic acid must be stored in good and dry places, and it must be used to prevent the source of fire and pollution. Its containers are also sealed to prevent its escape and damage. It must be prepared according to the appropriate conditions. It is also suitable for anti-pollution and emergency supplies, and it is also suitable for people to be trained and familiar with its dangerous characteristics and methods.
Acetic acid is corrosive, and it is suitable for storage in buildings, rooms, and oxidized and other incompatible materials. The container also needs to be made of corrosion-resistant materials, and the seal must be good to prevent leakage. If there is any leakage, it is necessary to abide by the relevant regulations and pay attention to prevention. If there is any leakage, it is necessary to follow the correct law to avoid corrosion of other things or endangering people.
Both are dangerous chemical products, whether they are stored or not, they are all compliant with safety standards, and the amount, flow direction and other information of the product can be checked. And the warning is clear, so that everyone can be alerted to its danger, and comprehensive prevention can be done to prevent accidents and ensure the safety of people and the safety of the environment.

In today's market, the price of Qizhi varies depending on its quality and source. The upper-class Qizhi is collected from the spiritual land of Qizhou. Its qi is clear and rich, the quality is firm and the lines are fine, and the higher price can reach a hundred gold. This is because of its excellent medicinal effect, it is important for doctors, and it is mostly used in rare prescriptions.
Medium Qizhi, although it is not as good as the upper-class essence, it still has considerable medicinal power, and its price is about tens of gold. Its production is slightly inferior, but it is also suitable for many common prescriptions.
As for the lower-class Qizhi, it is either not at the time of collection, or the place is not good, the quality is slightly inferior, and the taste is slightly lighter. The price is only a few gold.
And the price of Alisma is also equally different. Jiapin Alisma is large and solid, white and moist in color, and the price is between tens of gold. Because of its significant moisturizing power, it is indispensable for moisture removal agents.
Ordinary Alisma, slightly inferior in texture, is about ten gold. Although the efficacy is slightly slower, it is also the choice for ordinary moisture removal.
Lower Alisma, or defective, or long-lost, or only a few gold, only suitable for mild diseases or adjuvant agents.
The price of these two in the market is roughly the same. However, the market situation changes, and the price also changes with supply and demand and years. Pharmacists and doctors should pay close attention.