Comprehensive index book of Taoist scriptures: edited by Xu Zhenjun and Shi Xin: Number of volumes: Orthodox Taoist scriptures: Hanfen Loushu No.601,Xinwen Fengshu No.32, Sanjiashu No.0/9, Taoist scriptures: No.945, China Taoist scriptures: Four Auxiliary True Classics, Taiqing Elixir Classics No.1/kloc-. Xu Zhenjun's stone letter was written by an unknown person. From the content point of view, it seems that it was compiled by the Taoist priest in Xishan, Hongzhou in the Southern Song Dynasty, and Xie Shouhao, Zhu, Zheng Daoquan and others were handed down from generation to generation. The original book consists of two volumes, which are included in the various techniques of the Taoist temple. The book is orderly, claiming that Xu Zhenjun "pulled out his house in 374, the second year of Jinning Kang in East China, and flew in the western hills of Hongzhou, leaving a stone letter." Later generations found nine ciphertexts from the stone letters, called Records of Stone Letters, which were used for practicing Taoism on the basis of alchemy. Its nine titles are as follows:

Sun Yuanjing talks about the nature of the sun and the moon and the medicine Dan, about the right and wrong of medicine Dan, about cinnabar, preaching the truth, singing sacred stones, referring to the mystery of the sacred chamber, talking about Jin Dingxu, discussing the formation and change of cinnabar, the origin and nature of medicine, the parents and ministers of stone, the establishment of the cauldron, the generation and development of Yin and Yang and the five elements, the evolution of heat and so on. Generally, it draws lessons from the theory of yin and yang, five elements and divination in Shen Tong Qi, and the theory of stealing three talents in Yin Fu Jing. In words, inner alchemy is the way to practice. It is said that innate qi can biochemical three talents and everything, and it is the foundation of returning to Dan and the mother of great doctors; Then "it's not the land of eight stones, cinnabar and mercury." An alchemist must follow the theory of cosmic luck, so that Yin and harmony are combined into one, and the four images are combined into one, forming alchemy. This book is well written.