How does Shen Nong's Classic of Materia Medica record alchemy?

It has long been recognized in the world that alchemy originated in China and became the pioneer of modern chemistry. For example, Shennong Materia Medica "Cinnabar can be turned into mercury" is an enlightening record in this respect. The motivation of alchemy lies in the alchemist's attempt to refine the so-called immortal medicine, which is of course idealistic and superstitious, but objectively it led to the beginning of medicinal chemistry, improved and expanded the application scope of chemical drugs, and promoted the development of traditional Chinese medicine pharmacy (especially surgical drugs).