Pour 1½ cups of distilled water into a saucepan. Distilled water has a neutral pH of 7, so it is not too alkaline or acidic, which can affect the results of the crystal-forming experiment.
Bring the distilled water to a boil on medium heat. Add 2 teaspoons of Epsom salt and stir the mixture so that the salt dissolves. Continue the process of adding, stirring and dissolving salt until the water becomes saturated with salt and no more salt can dissolve.
Pour the solution into a glass jar. Measure the length from the solution to the top of the jar. Cut a piece of string 1 inch longer so when hanging from the top of the jar, the string will dangle into the mixture.
Tie the string on one end of a pencil. Tie the loose end of the string to a paper clip. Balance the pencil on the top of the jar so that string and paper clip dangle within the jar.
Cover the top, sides and bottom of the jar with a kitchen towel. Place the jar on a flat surface and allow it to cool at room temperature. Crystals will form on the paper clip and string as the salt and water mixture evaporates. Check the jar in three days, at which point a stalactite crystals should form.