Materials:
A glass jar or clear drinking glass
Vegetable oil
Salt
Water
Food coloring (if you want)

Instructions:
Pour about 3 inches of water into the jar.

Pour about 1/3 cup of vegetable oil into the jar. When everything settles, is the oil on top of the water or underneath it?

If you want, add one drop of food colouring to the jar. What happens? Is the drop in the oil or in the water? Does the colour spread?

Shake salt on top of the oil while you count slowly to 5. Wow! What happens to the food colouring? What happens to the salt?

Add more salt to keep the action going for as long as you want.