2-iodo-5-phenylthiophene

In "Tiangong Kaiwu", it is recorded that the main uses of Western guns (guns, the old name for guns) are as follows:
First, it is used for war attack and defense. Western guns are powerful and can be used as offensive weapons on the battlefield. Their range is relatively long, and the projectiles fired have a large lethality, which can cause huge damage to enemy soldiers' arrays, fortifications, etc. During siege, they can use their power to collapse city walls, destroy city gates, and open passageways for their own troops. When defending the city, they can be fired from the city wall at the enemy who is attacking the city, killing the enemy from a long distance, effectively preventing the enemy from approaching the city, and greatly changing the offensive and defensive situation of the war.
Second, it is used for coastal defense. During the Ming Dynasty, the coast was often invaded by maritime forces such as Japanese pirates. Western guns were equipped on coastal guards, batteries and naval warships, becoming an important force in coastal defense. When enemy ships are close to the coast or cruising at sea, Western guns can be used to attack. Its powerful firepower can cause damage to enemy ships at a long distance, damage their hull structure, and make them incapable of combat, thus ensuring the security and stability of coastal areas.
Third, it is used for deterrence. Western guns have a certain deterrent effect in diplomatic and military displays due to their unique structure and strong power. When foreign envoys visit or there is a potential conflict with surrounding forces, displaying advanced firearms such as Western guns can demonstrate the country's military strength and technical level, so that the other party does not dare to provoke easily, and to a certain extent, it has the effect of subjugating the enemy without fighting, maintaining the country's peace and diplomatic status.

Saltpeter is an important agent for gunpowder and has various physical and chemical properties. Its pure color is often colorless and transparent, and its shape is like crystalline, but it also has white and light yellow colors due to impurities. It is brittle and fragile, with different crystal shapes, either columnar or needle-like.
Saltpeter is very soluble in water, and its solubility increases sharply with the rise of water temperature. When dissolved, it absorbs heat and causes water temperature to drop, which is a significant physical property.
As for chemical properties, saltpeter is mainly composed of potassium nitrate. It can be decomposed when heated and releases oxygen. This property makes it able to support combustion in the combustion reaction, which is the key reason for the deflagration of gunpowder. In case of acid, nitric acid can be produced, and nitric acid has strong oxidizing properties, which is also related to the chemical activity of saltpeter. When it encounters some metal salts, it can cause a complex decomposition reaction to form new salts.
In ancient times, saltpeter was widely used. In the military, it was the main raw material for making gunpowder. Gunpowder, with the power of saltpeter to support ignition and detonation, was used in firearms and artillery, and its power was extraordinary on the battlefield. In the civilian, it was also used for making ice. In the hot summer, saltpeter is used to dissolve water and absorb heat, which can cool and freeze water for people to cool off. And in the field of medicine, it also has its use, with the effect of clearing heat and purging fire. However, it should be used with caution and follow medical principles.

The chemical synthesis method of aspirin is not mentioned in "Tiangong Kaiwu", because aspirin was only synthesized at the end of the 19th century. "Tiangong Kaiwu" was written in the ten years of Chongzhen in the Ming Dynasty (1637), and the times are far apart. However, from the perspective of traditional chemical processes, it can be imagined that the ancients tried similar synthesis possible ideas.
If you want to get aspirin-like things, you should first focus on the acquisition of salicylic acid. Plants such as willow bark contain this ingredient in nature. In ancient times, Fangjia and doctors may know that willow bark can relieve pain. If you want to extract it, you should take fresh willow bark, remove its coarse skin impurities, chop it and soak it in water or wine. The water is mild, but the wine soaking is because of the strong solubility of alcohol, or more active ingredients can be extracted. After soaking, filter the liquid, and then evaporate to reduce the solvent and concentrate the active ingredients.
However, aspirin is acetylsalicylic acid, which needs to be acetylated. Although the ancients did not have modern acetylation reagents and precise control methods, they may try to use natural and easy-to-obtain things such as acetic anhydride. Acetic anhydride can be obtained occasionally in ancient vinegar brewing processes. Mix the concentrated salicylic acid solution with an appropriate amount of acetic anhydride, or find an appropriate warm environment to promote its reaction. However, due to the lack of accurate temperature control and catalytic knowledge, the reaction may be difficult to complete efficiently. After the reaction, it is difficult to separate and purify the product. Without modern chromatography and crystallization techniques, only rough methods such as multiple filtration and recrystallization can be used to remove impurities as much as possible to obtain a relatively pure product. Although this idea is far from modern aspirin synthesis, it is also a way that the ancients could try under the conditions at that time.

"Tiangong Kaiwu" contains that the price of the genus of the lotus root varies according to time, place and appearance. The lotus root, that is, the root of the lotus root, is often sold in the market, and the price changes.
The lotus root is mostly born in the water towns of Zeguo, and its production is abundant, and the price may be slightly flat; if it is in remote soil, or when the weather is not smooth, resulting in sparse production, the price will be high. And its quality is also the main reason for pricing. Those with good quality have a good shape and smooth color, a firm texture, and a good taste and quality, and their price will be high; those with poor quality have a dark residual color, loose texture, astringent taste and poor quality, and the price will be lower accordingly.
Usually, the price of lotus root in the market is about a few to tens of dollars per catty. In good years, the water towns are full of lotus root, and its price may fall to the spectrum of a few dollars per catty to meet the daily needs of the common people; but in the age of apology, or in times of disaster, the production of lotus root has dropped sharply, and the demand in the city is too high, and the price jumps, and each catty can reach tens of dollars, even more than a hundred dollars, making it difficult for ordinary people to buy lightly.
There are also regional differences. Near the place of origin, the freight is saved and the cost is low, and the price is easy; if it is sold to other parties, the price will increase due to the cost of transshipment and the consumption of preservation. And a prosperous city, where wealthy households gather, there are good delicacies and delicacies. The lotus root is here, or it is a good choice for banquets, and the price is often higher than elsewhere.
However, the business city is impermanent, and the price of the lotus root is uncertain. It changes with the year, region, and supply and demand trends. If you want to know the real-time price, you must go to the city in person and ask the merchants to be sure.

It is recorded in "Tiangong Kaiwu" that where the ink burns the smoke and coagulates it. The method of its manufacture is to prepare tung oil, clear oil or lard, burn it in a small kettle, and cover it with a plate. The smoke is gathered on the plate and scraped off. Another method of making smoke is to use pine wood as raw material, burn the smoke in the kiln, and sweep it after cooling.
The condensation of ink is made of skin juice. For skin juice, the glue fried from cowhide or donkey skin is also used. The smoke and glue are mixed in proportion, adding spices and other substances, and repeatedly beating them to make them integrate evenly. The more times you beat, the firmer the ink quality.
The preservation of ink, the first heavy drying. Place it in a well-ventilated and dry place. If it is in a humid place, the ink is prone to moisture and mildew, which will damage its quality. Second, avoid direct exposure to strong light. Strong light can fade the pigments in the ink, affecting the effect of writing and painting. Third, avoid heavy pressure. Although the ink body is strong, it may also break and break under heavy pressure. Proper storage can obtain the long-term utility of ink for the needs of writing and painting.