This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
Place a few scrapings from gum camphor in a tumbler of water and watch the phenomenon. The scrapings will go through all kinds of rapid motions as if they were alive. A drop of turpentine, or any oil, will stop their maneuvers. This experiment will show how quickly oil spreads over the surface of water.