ciency in optical illusions. In the Middle Ages magic was greatly in vogue. Later on Nostradamus conjured up the vision of the future king of France for the benefit of the lovely Marie de Medicis. This illusion was accomplished by the aid of mirrors adroitly secreted amid hanging draperies. Reginald Scott, in 1584, in Discoverie of Witchcraft, enumerates the stock feats of the conjurers of his day. The list includes "swallowing a knife; burning a card and reproducing it from the pocket of a spectator; passing a coin from one pocket to another; converting money into counters, or counters into money; conveying money into the hand of another person; making a coin pass through a table, or vanish from a handkerchief; tying a knot, and undoing it 'by the power of words'; taking beads from a string, the ends of which are held fast by another person; making corn to pass from one box to another; turning wheat into flour 'by the power of words'; burning a thread and making it whole again; pulling ribbons from the mouth; thrusting a knife into the head or arm; putting a ring through the cheek; and cutting off a person's head and restoring it to its former position."
A number of these feats, in an improved form,
