world. Needham and Lu proposed this langgan hua probably refers to a red or green poisonous mushroom, and Knoblock surmised that these "ruby blossoms" were a species of hallucinogenic mushroom connected with the elixir of immortality. Another Zhen'gao context describes how in the Shangqing latter days before the apocalypse (predicted to be in 507) people will practice alchemy to create immortality drugs, including the Langgan Elixir that "will flow and flower in thick billows" and Cloud Langgan. If the adept takes one spatula full of elixir, "their spiritual feathers will spread forth like pinions. Then will they (be able to) peruse the pattern figured on the Vault of Space, and glow forth in the Chamber of Primal Commencement". Several ingredients in the Elixir of Langgan Efflorescence are toxic heavy metals including mercury, lead, and arsenic, and alchemical elixir poisoning was common knowledge in China. Academics have puzzled over why Daoist adepts would knowingly consume a compound of mineral poisons, and Michel Strickmann, a scholar of Daoist and Buddhist studies, proposes that langgan elixir was believed to be an agent of self-liberation that guaranteed immortality to the faithful through a kind of ritual suicide. Since early Daoist literature thoroughly, "even rapturously", described the deadly toxic qualities of many elixirs, Strickmann concluded that scholars need to reexamine the Western stereotype of "accidental elixir poisoning" that supposedly applied to "misguided alchemists and their unwitting imperial patrons". Literature Chinese authors extended the classical descriptions of langgan meaning "a highly valued gem from western China; a mythical tree of immortality on Kunlun Mountain" into a literary and poetic metaphor for the exotic beauties of an idealized natural world. Several early writers described langgan jewelry, both real and fictional. The 2nd-century scholar and scientist Zhang Heng described a party for the Han nobility at which guests were delighted with the presentation of bowls overflowing with zhēnxiū 珍羞 "delicacies; exotic foods" including langgan fruits of paradise. The 3rd-century poet Cao Zhi described hanging "halcyon blue" (cuì 翠) langgan from the waist of his "beautiful person", and the 5th-century poet Jiang Yan adorned a goddess with gems of langgan. Some other authors reinforced use of its name to refer to divine fruits on heavenly trees. Ruan Ji, one of the Seven Sages of the Bamboo Grove, wrote a 3rd-century poem titled "Dining at Sunrise on Langgan Fruit". The 8th-century poet Li Bai wrote about a famished but proud