In feudal society, aristocratic bureaucrats dreamed of immortality in order to enjoy a life of luxury and debauchery forever. Some people want to refine the "elixir of immortality" to satisfy their extravagant desires, so they form an alchemy.
Alchemy has a long history. As early as the Warring States period in the third and fourth centuries BC, there are records of alchemists and searches for "immortal medicines".
Qin Shi Huang once sent Xu Fu to Penglai with hundreds of men and women to ask the immortals for immortal medicine. Emperor Wu of Han recruited many alchemists to emphasize the art of immortality. Alchemy flourished with the help of the feudal ruling class. During the Wei and Jin Dynasties, alchemists evolved into Taoist priests who used rune water to treat diseases. They regard Lao Tzu, the founder of the pre-Qin Daoists, as their ancestors. Since then, Taoism has become one of the main religions of China's feudal society, on an equal footing with Confucianism and Buddhism.
The alchemist puts some minerals into a sealed din and burns them with fire. Minerals undergo chemical changes under high temperature and pressure, producing new substances. However, in the process of alchemy, some laws of material change were discovered, thus forming the precursors of modern chemistry.
Alchemy developed relatively early in China, and Ge Hong was one of them.
Ge Hong's name was Zhichuan (稚川), dao number: Baopuzi (抱朴子), a Jurong person from Danyang in the Eastern Jin Dynasty. His grandfather was born into a declining aristocratic family and was a high-ranking official of the State of Wu during the Three Kingdoms period. At the age of 13, his father died of illness and his family was in a terrible situation. Ge Hong has had a strong desire for knowledge since he was a child. Without books, he went around borrowing books from others. Without money to buy pens and ink, he practiced writing on the ground with charcoal. At the age of 16, he began to read Confucian books such as the Book of Filial Piety and the Analects. Ge Hong read many books extensively, from scriptures and history books to essays, and he carefully read all the books he could borrow. Later, he also learned "Wangqi" and "Bu Gua"
After a long period of hard self-study, Ge Hong finally became a knowledgeable person. According to the biography of Ge Hong in the Book of Jin, Ge Hong was "well-informed," well-informed and knowledgeable; the writers of the chapters were rich in Banma, that is to say, Ge Hong's knowledge was very rich and unparalleled in the Jiangnan region. His works are more than those of Ban Gu and Sima Qian, including 116 volumes of "Baopuzi" in the Golden Book, 100 volumes of epigraphic poems, 10 volumes of "Immortals", "Good Officials", "Hidden Escapes", and "Jiyi", 310 volumes of "History of the Five Classics" of more than 100 scholars, 100 volumes of "Outline of the Golden Plateau", and 4 volumes of "Urgent Fang After the Elbow". One man has so many works, copied 310 volumes. As you can imagine, he was very diligent.
In the last years of the Western Jin Dynasty, the ruling class fought for power and interests, the "Rebellion of the Eight Kings" and the "Barbarian Rebellion". Wars have arisen one after another, the social productive forces have been severely damaged, the class struggle has been very acute, and peasant uprisings have sprung up. Living in this situation, Ge Hong, like some landlords, turned to heaven out of disappointment with reality and devoted himself to the art of immortals and scholars. Ge Hong fully developed Zhuangzi's theory into the art of immortals and scholars. His thoughts are essentially inner immortals and outer Confucians. His alchemical theory is based on this idea. He believed that all matter could be changed, and that with sincere demands and appropriate conditions, one could practice the elixir and gold. According to this theory, Ge Hong conducted a large number of alchemy experiments while collecting and studying various healing formulas.
From these alchemical experiments, Ge Hong was familiar with the composition of many inorganic substances and some simple chemical reactions. We can find from the inner chapter of the Baopuzi that Ge Hong only has the following knowledge of chemistry:
(1) "Dansha burns into mercury, and the accumulation changes back into Dansha." Cinnabar is mercury sulfide, which is decomposed by heating to obtain mercury. Mercury and sulfur combine to form black mercury sulfide, which is then adjusted in a closed container and then added to The Huawei red crystalline mercury sulfide. In other words, Ge Hong discovered the reversibility of chemical reactions during mercury refining. He pointed out that heating dansha (mercury sulfide) can refine mercury, and the combination of mercury and sulfur can become dansha.
(2) "Paint iron with zengqing, and iron is red as copper." Zeng Qing may refer to alum containing copper sulfate. Zeng Qing painted iron with a solution of iron and copper sulfate. Iron replaces the copper in copper sulfate, so there is a layer of copper on the surface. Due to the coating method, copper sulfate only works on the surface of iron. Ge Hongjin said, "Change the outside, but not the inside." It can be seen that Ge Hong carefully observed this metal replacement reaction.
(3) "Lead is self-contained, and red is thought to be dan, dan is red, and white is thought to be lead." This means that lead can turn lead white, i.e. alkaline lead carbonate, and lead white can turn into red lead, i.e. lead trioxide; lead can turn white and finally lead. This is an obvious chemical reaction process.
(4) "Take the female yellow and the male yellow, and take it down, in which the copper is cast as a vessel to restore it... For 100 days, this vessel is full of red milk, and it is several minutes long." In other words, both female yellow (arsenic trisulfide) and male yellow (arsenic pentasulfide) can be sublimated after heating. Ge Hong's words are descriptions of their sublimated reflections.
At that time, Ge Hong had such a wealth of chemical knowledge. In the development of Chinese alchemy, he was the link between the past and the future. His inspiring writing style preached alchemy. His specific writings on alchemical methods had a great influence on later alchemists.
Alchemy is mysterious in the eyes of many, and some people directly equate it with feudal superstition. In fact, the ancients began to explore the material world through alchemy, so chemistry entered the embryonic stage.