Each magnet has its poles, north and south--the north or south poles
of one magnet repel the north and south pole of another. If a magnet
be dipped in some iron filings, they will be immediately attracted to
one end. Supposing this to be the north pole, each of the ends of the
filings, not in contact with the magnet, will become north poles, while
the ends in contact will by induction become south poles. Both will
have a tendency to repel each other, and the filings will stand on the
magnet.