When the senior sister talked about the refining of this foreign pill, she talked about the promotion of the pill for our country's science and technology, which not only made me think of alchemy, but I asked her if there was a connection between this alchemy and alchemy.

Senior sister was silent for a while, and said the connection, which also opened my eyes.

Alchemists not only refine the elixir that can make people "immortal" through the fire method, but also use the elixir to "turn iron into gold". Ge Hong's "Hug Puzi? The Jin Dan Chapter says: "When the divine pill is completed, it is not only immortal, but also can be used as gold." "Why do you want to ignite gold? Wei Boyang said in "Zhou Yi Shen Tong Deed": "Gold is invincible, so it is a treasure." Therefore, alchemists believe that human beings can transfer their properties to the human body by taking gold, silver, jade and other "immortal" substances, which can make the flesh and blood also "invincible", and then lead to the alchemy method to refine gold and silver, that is, mercury (mercury) and base metals such as lead, copper, iron and other base metals are smelted into yellow or white gold or silver in different proportions.

Therefore, the outer Danshu is also known as the Jindan technique or the yellow and white arts. The Wai Dan technique igniting gold and silver belongs to a metaphysical viewpoint in terms of ideological understanding, which is fully reflected in Ge Hong's "Hug Puzi? In the Yellow and White Chapter: "The one who changes is the nature of the land, so why should gold and silver not be made of foreign objects?" He cites the occasional birth of mules and donkeys (donkeys) intersecting, and the transformation of molten lead into huangdan and hu powder, and puts forward the idea that various substances in nature can not only change, but also change infinitely; But it completely ignores the conditions for the transformation of things, and absolutizes the change. In fact, although the color of the gold and silver made by the alchemist through the mercury smelting method of flying sand is similar to that of gold and silver, they are not real gold and silver, but are used as medicinal alloys, called medicinal gold and medicinal silver.

This kind of medicinal gold and medicinal silver were still relatively valuable in ancient times. The so-called "gold into the medicine." "In the eyes of ancient alchemists, whether or not the refined divine pill can be ignited with gold and silver is regarded as an important indicator of the success of cultivation; If you can't do it, you need to adjust the heat according to the changes in the hexagram, smelt it repeatedly, and turn it into a pill after nine turns. Because of its partial effect, it is also called "Danmu".

In addition to these, Waidan also has a very close connection with gunpowder. Gunpowder was first invented by the Chinese, and there is a record of sulfur, one of the components of gunpowder, in the Taoist classic "Huainanzi" in the Western Han Dynasty. In the Shennong Classic of Materia Medica, sulfur and saltpeter are listed as high-grade medicines that can cure diseases. Saltpeter is also a mineral, produced in Sichuan and Gansu. It is a strong oxidizing agent, which can release oxygen when heated, and is easy to smoke and fire, so it is also called smoke or fire nitrate. Due to the active chemical properties of saltpeter, it can interact with many substances, so alchemists often use saltpeter to change the properties of other medicines in alchemy.

In the Western Han Dynasty, Chun Yuyi used saltpeter to treat Wang Meiren's disease. In their long-term alchemy practice, alchemists constantly mixed and calcined saltpeter, sulfur, realgar and pine resin, grease, charcoal and other materials, which made the invention of gunpowder inevitable.

Alchemists also conducted "experimental" observations and studies on the various properties of sulfur, and they found that sulfur can not only react with copper and iron, but also subdue the miraculous mercury (mercury). Sulfur is chemically very reactive, easily igniting and reacting with oxygen in the air, which makes it difficult for people to subdue it. In order to tame its violent nature, the ancients tried to "ambush" the sulfur.

According to the theory of yin and yang, the five elements and the visceral meridians in the theory of traditional Chinese medicine, alchemists believe that saltpeter and sulfur are both yang things, because they can catch fire, and there will be the poison of yang fire, which can corrupt people's internal organs. In order to make people not only have no toxicity after ingestion, but also moisturize the five internal organs, so that the five internal organs in the human body can be harmoniously blended, and help longevity, it is necessary to try to subdue the fire poison, which is the "ambush fire". The specific method of "ambushing the fire" is also very simple, that is, "fighting poison with poison", burning it with fire, and the fire poison will be naturally eliminated.

In the practice of alchemy, the monks gradually discovered that sulfur, saltpeter, and charcoal were mixed together, and if they were not done well, they would cause combustion or even explosion. This happened a lot, and naturally attracted the attention of the alchemist. As a result, there are people who specialize in these kinds of experiments, constantly accumulating experience and improving the formula. Since sulfur and saltpeter are both curative medicines, and because they can be combined with wood charcoal to cause fire, people call the mixture of these three things gunpowder, which means "fire medicine". Because the color of this mixture is close to black, it is often referred to as black powder. The earliest record of the formula and combustion of black powder comes from the book "The Sulfur Method of the Dan Jing" written by Sun Simiao, a famous Chinese medicine practitioner, "medicine king", health practitioner and alchemist in the early Tang Dynasty. This is also the world's earliest record of the original formula of gunpowder for light industry. It describes the method of ambushing sulfur: bury a sand pot or a silver pot in the soil, the mouth of the jar or pot is flush with the ground, and the surrounding area should be compacted with soil, and two taels of nitrate and sulfur should be put into it. Then burn the three canes of soaphorn with fire, not to ashes, but to charcoal, and then put them into a pot or pot one by one. At this time, the freshly burned soaphorn comes into contact with saltpeter and sulfur with the embers, and the nitrate and sulfur will automatically burn. After waiting for the smoke to rise, he piled charcoal on the mouth of the jar and heated it, and the recipe for a servage of black powder was obtained. Here, the three main components of black powder are ready: nitrate, sulfur and charcoal. Just because the charcoal is not crushed and not fully and evenly mixed with nitrate and sulfur, the reaction is not violent enough. In addition, the purpose of "ambush fire" is to prevent and avoid violent combustion and explosion, and some measures only cause the reaction to appear as a result of purple and blue fireworks. This is also related to the invention of fireworks and firecrackers.

The method of Wai Dan that Senior Sister said seems to be miraculous enough, but how does this Wai Dan subdue that little ghost? Speaking of this, Senior Sister pointed to a protrusion in the racecourse and said that it was the Fa that was done there in the first place.

(To be continued)