Blood
Probably the most critical symbol in the play, blood symbolizes the guilt of Macbeth and Lady Macbeth. It is associated with stains and signs of misdeeds which cannot be washed away or stains which would spread to everything it touches. Blood is also the symbol of natural order. The proper bloodline of kings, when cut by treachery, leads to chaos and crime. When the bloodline is restored so is order and justice.
The Weather
When the witches appear to bring magic and propel disorder they are accompanies by storms and atmospheric disturbances. Each murder and act of treachery are also associated with storms. With the coming of restored order, the skies return to calm. The themes of the natural and the supernatural are punctuated by the weather in the play.
