An adhesive is a compound that adheres or bonds two items together. Adhesives may come from either natural or synthetic sources. Some modern adhesives are extremely strong, and are becoming increasingly important in modern construction and industry. History The first adhesives were natural gums and other plant resins or saps. It was believed that the Sumerian people were the first to use it until it was discovered that Neanderthals as far back as 50,000 years made adhesives from birch bark. T… (More on Adhesive)