PROCEDURE1. Pour each of three different types of milk into three clean plastic plates so that it completely covers the bottom. Fill a fourth plate with water.
2. Add a couple of drops of four, differently colored, water-soluble food coloring near the edge of the plates.
Arrange the drops so that they are in positions equivalent to 3, 6, 9, and 12 on a clock. Observe changes.
3. Dip the tip of a toothpick in detergent.
Touch the surface of the milk (and water) in the center of the pie pan and hold the toothpick in place for a timed period of time.
Observe.
4. Experiment with the milk and toothpick.
