  Sun was also the author of several works on Daoist alchemy, which he is believed to have practiced (he died at the age of 101). These include the Essential Instructions from the Scripture of the Elixirs of Great Clarity (Taiqing Danjing Yaojue, ca. 640), an anthology of some thirty selected methods (Sivin 1968, 262–264). His “Essay on Preserving and Nourishing Life” (Sheyang lun 攝養論) gives monthly advice on food, sleeping habits and action of good and ill auspice (Predagio 2013,928).