Fill a clear bottle or jar about three-quarters full with vegetable oil
Add water until the container is nearly full, leaving some space at the top
Add a few drops of food coloring to the water layer
Break an effervescent tablet into small pieces
Drop one piece into the container
Watch the bubbles rise and fall
Add more tablet pieces as needed to keep the effect going
Seal the container only if you are not using it again soon
Keep the lamp on a stable surface away from heat and children