text: Needham's "silver age of Chinese alchemy" (c. 800-1300) was from the late Tang to the end of the Song dynasty. During the Tang,  literature gradually changed from emphasizing ritual practices to cosmological principles. Early Taiqing tradition texts stress the performance of alchemical rites and ceremonies when compounding, and described elixirs as tools for either summoning benevolent gods or expelling malicious spirits. Most post-Tang  texts related to  alchemy stress the cosmological significance of elixir compounding and employ numerous abstract notions. After the late Tang period,  gradually declined and the soteriological immortality significance of alchemy was transferred to .
  Imperial interest in alchemy continued during the Song dynasty (960-1279). Emperor Zhenzong (r. 997-1022) established a laboratory in the Imperial Academy, where the Daoist alchemist Wang Jie  "produced and presented to the throne artificial gold and silver amounting to many tens of thousands (of cash), brilliant and glittering beyond all ordinary treasures".
  Most  sources dating from the Song and later periods are either anthologies of earlier writings or deal with metallurgical techniques.  alchemy subsequently declined in the Yuan, Ming, and Qing dynasties.