In ancient China, our Chinese ancestors called our sublingual part “Xun Ying” in Chinese. There were two apertures; the left one was called “Jin Jing” (the juice of excellence) and the other one was called “Yu Ye” (the juice of jade). When the essence of the body ran to the “Yu Chi” (the pond of jade), formally called oral cavity, the two apertures would secrete saliva so it was called “Yu Ye” (the juice of jade).