Two legends, namely: "While he awaited a tonic, Qin turned to mercury tablets." and then a map where: "rivers of quicksilver represent the kingdom’s waters"

Two legends, namely: "While he awaited a tonic, Qin turned to mercury tablets." and then a map where: "rivers of quicksilver represent the kingdom’s waters" finally some modern evidence: "Modern investigations have been able to corroborate this legend with some chemical evidence. In 2005, a research team led by Chinese archaeologist Duan Chingbo took 4,000 samples from the earthen mound to test for Mercury, and all of the samples came back highly positive." Which legend would you think that should be supporting? Sometimes I just don't understand the thought process going into an article.