Silly Putty is a popular kids' toy and you can make a version of it at home. Most recipes for homemade Silly Putty call for liquid starch or borax. If you do not have these ingredients on hand or if you prefer a safer alternative, make homemade Silly Putty with Epsom salts instead.
Bouncing putty was invented by accident in an American laboratory during World War II. Japan had invaded several rubber-producing countries, putting the United States' supply of rubber for military use in jeopardy. U.S. scientists were asked to create a synthetic compound that could replace rubber for applications like truck tires and boots for soldiers. Bouncing putty was a result of James Wright's experiments at a General Electric lab. While a practical use for the bouncing putty was never found, it eventually caught toymaker Ruth Fallgatter's attention. Fallgatter and marketer Peter Hodgson sold the first bouncing putty in a 1949 toy catalogue. Fallgatter lost interest, but Hodgson went on to sell the product on his own as Silly Putty.
The ingredients needed for homemade Silly Putty are 1/2 tsp. Epsom salts, 1/2 tsp water and 1 tbsp white glue. You also need measuring spoons, two small cups for mixing the ingredients, a spoon or stir stick, waxed paper and a small resealable plastic bag.
First, stir together 1/2 tsp of Epsom salts and 1/2 tsp of water in a cup until the Epsom salt is dissolved as much as possible, even if it does not dissolve completely. Put 1 tbsp of white glue into another cup. Now pour the Epsom salt and water into the cup with the glue and stir it all together. Play with your putty on a piece of waxed paper if you do not want to make a mess and store it in a sealed plastic bag to keep it for later.
About Epsom salts
Neither liquid starch nor borax is considered a dangerous substance, but they can both cause skin or eye irritation and are harmful if swallowed, so Epsom salts are slightly safer for kids. Epsom salt (magnesium sulphate) is a naturally occurring mineral that is used by many systems in the human body. Epsom salts can be taken orally for medicinal purposes by dissolving and diluting them in water. They are also used as a soak.