Masters with X-ray eyes appear frequently within Chinese folklore. According to the book "To Live As Long As Heaven and Earth: Ge Hong’s Traditions of Divine Transcendents," immortals were able to read a person’s skeletal structure to tell if they were fated to become immortals themselves. For instance, the Hagiography of the Immortal "Wang Yuan" () states he was traveling through the Wu state on his way to "Mount Guacang" when he spied the peasant "Cai Jing" (). Wang could tell “...his bones and physiognomy indicated that was fit for [eventual transcendence.”