[A new interpretation for "Knockout Drops" (menghan)].

Knockout drops ("menghanyao" in Chinese) is named as one of riddles in the cultural history of China. Why its is named as "menghan" has been interpreted from the viewpoint of phonology by many former solons. A new opinion is put forward from the viewpoint of pharmacology and physiology in this paper, in which a historical fact is concerned that mandala is the essential component in knockout drug. The function of sweat gland is inhibited with sweat retained inside the human body after knockout drops are taken. "Menghan" just describes the above physiological phenomenon.