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Purpose
To demonstrate the formation of stalagmites and stalactites.

Procedure
1.	Fill each jar with Epsom salt. Add just enough water to cover the Epsom salt and stir.
2.	Tie a washer to each end of the string.
3.	Place one washer in each of the jars and place the sheet of paper between the jars.
4.	Position the jars so that the string hangs between them with the lowest part of the loop about 1 inch (2.5 cm) above the paper.
5.	Allow the jars to stand undisturbed and out of any draft for 1 week or longer.

Results
Water drips from the center of the loop onto the paper. A hard, white crust forms on the string and grows down as time passes. A mound of white crystals builds up on the paper beneath the string.

Why?
Water containing Epsom salts moves through the string. As the water evaporates, crystals of Epsom salts are deposited. The Epsom salts formations are models of how crystals deposits form in caves. Stalactites are icicle-shaped crystals that hang from a cave's roof. Stalagmites are crystals that build up from the floor of the cave.