In a dish (such as a bowl) place a large cinder or
pieces of charcoal, porous stones or pieces of brick.
Mix together six tablespoons each of water, table salt
and bluing. Mix well and let stand an hour. Then add
one tablespoon ammonia. Stir briskly. Pour over cinder,
charcoal or stones. To give color, add drops of cake
coloring here and there. Place it where it won't have to
be moved or bumped so the formation won't crumble.
More solution can be added when action stops, which
may not be for a week or ten days. Add carefully at the