A chair in a dream can point to status -- who holds a position of authority, or who's missing from one. An empty chair often reflects someone absent from your life whose presence you still feel, while sitting and waiting in one can mirror a decision you're putting off making.
Mars occidental in Cancer not beheld of Saturn, Jupiter, Venus, or Sun, makes a good phlebotomist. But if Mars shall be in Capricorn, it makes a destroyer of men, and one that delights to shed blood. - William Lilly (1602.-1681.)