In his "Regiment of Life" Thomas Phaer says:". . . which humours are called ye sones of the Elements because they be complexioned like the foure Elements, for like as the Ayre is hot and moyst: so is the blooud, hote and moyste. And as Fyer is hote and dry: so is Cholere hote and dry. And as water is colde and moyst: so is fleume colde and moyste.