IV. To file the card.--To file the card is, when a card has been
taken from the pack to pretend to place it about the middle of
the pack, whilst, in reality, you place it at the bottom.
The pack must be held in the left hand, between the thumb and
forefinger, so that the three other fingers be free. One of the
middle cards should project a little. Then take the card to be
filed between the forefinger and the middle finger of the right
hand; advance the right hand from the left, and whilst the three
disengaged fingers of the left hand seize and place the card
under the pack, the thumb and forefinger of the right seize the
projecting card before mentioned, so that it seems to be that
card which you have slipped into the middle of the pack. These
movements are very easy, and, when rapidly performed, the
illusion is complete.