Slime—that strange substance that defies Newton’s laws of viscosity—has been a staple in store toy aisles for almost 50 years and the DIY versions have been around almost as long. The typical school-science-project slime recipe involves mixing either borax or contact lens solution with PVA glue and water. The science behind it is a chemical reaction between the polyvinyl acetate in the glue and the borate ions in the contact solution or borax, an action called cross-linking that results in a logic-defying substance that is a whole lot of fun to play with. However, fascinating DIY science aside, too much ...