Why is it named after "medicine"? This should start with the history of gunpowder. It was not born in the field of ammunition from the beginning, nor was it invented by a military strategist, but was a by-product obtained by the alchemist of China refining the elixir of life.
The earliest invented gunpowder, black in color, is called "black powder" or "brown powder", and its main components are charcoal powder, saltpeter and sulfur powder. In remote ancient times, people thought that saltpeter and sulfur were both good medicinal materials.
Shen Nong's Herbal Classic in Han Dynasty once divided important medicinal materials into superior and inferior ones, among which saltpeter was considered as top grade medicine and sulfur was considered as traditional Chinese medicine, so it was used by alchemists to refine elixir of life.
In the Eastern Han Dynasty, Wei Boyang, one of the founders of Taoism and a famous alchemist, mentioned the use of sulfur in his alchemy work "Zhouyi Tongcanqi": "Cinnabar can be heavy or light, spiritual, black or white, dark or bright, and has the nature of five elements." The main components of cinnabar are mercury sulfide, sulfur and mercury. This Dan medicine is very toxic, and many emperors who pursued immortality in ancient times died of poisoning by eating Dan medicine.
In the Ming Dynasty, several emperors liked to eat Dan medicine, and Injong and Sejong even died because of eating Dan medicine. The ancients gradually realized the toxicity of cinnabar in practice and adopted various disinfection techniques. An alchemist is used to cauterizing to disinfect toxic epigraphy drugs, such as sulfur and arsenic. This method is called "reducing fire", which means using fire to reduce poison and turn poison into medicine.
Although there was no uniform poison, gunpowder was born. In order to reduce the toxicity as much as possible, the ancients made many attempts and changes to the "fire extinguishing method". Charcoal and saltpeter are two main raw materials for submerged fire method. Sun Simiao, a medical scientist in the Tang Dynasty, recorded the specific methods of reducing fire in the sulfur method in Dan Jing. Grind sulfur and saltpeter into powder, put it in a container made of silver pot, then put the container in a dug pit, level it with soil, and don't breathe.
Take out the powder in a few days, burn it in a pot, and then fry it with charcoal. In the process of reducing fire, charcoal powder, saltpeter and sulfur powder, which are important components of black powder, are combined together. Once burned, they will cause violent chemical reactions, so explosions often occur in the process of reducing fire.
After the ancients discovered the characteristics of explosion caused by the burning of these three substances together in the practice of alchemy, they called the medicine made of this kind of alchemy "burning medicine" or "gunpowder" in some medical works, and some reasonable points of gunpowder in treating diseases were also preserved. In the world medical masterpiece Compendium of Materia Medica, Li Shizhen clearly recorded the medicinal value of gunpowder: curing sores and tinea, sterilizing, preventing moisture and eliminating epidemic diseases.
Summary: Later, gunpowder was widely used in military activities, but its initial identity was indeed a kind of "medicine".