Objective: I would define the differences of sentences that ``A tongue can detect five basic tastes`` and ``A mouth can perceive the five cereals`` in Youngchu·Macdo(靈樞· 脈度). Methods: 1. I refer to literatures for the sentences in Youngchu·Macdo 2. I look into the symptoms which may be caused by heart and pancreas troubles, respectively. Result: Human being can not detect a specific taste on his heart trouble. That is, acid, bitter, sweet, hot, and saltness can be all one. Human being may lose his appetite on his pancreas trouble. Even though the viscera and the tongue are connected to on-meridians, the function of a tongue is managed and controlled by a heart. Such a tongue perceives five basic tastes. Conclusion: A healthy tongue appreciates five basic tastes clearly and a healthy mouth may stimulate his appetite.