Portland cement is the most commonly used type of cement in the world today. Portland cement can be found in both concrete and mortar, not to mention other construction mediums such as stucco and some types of grout, where it acts as a binding agent. On a chemical level, Portland cement is a fine powder comprised of a around 64% calciumoxide, with the remainder largely being a mix of aluminium, and iron. Portland cement is a hydraulic material, which requires the addition of water in order to form exothermic bonds, and is not soluble in water. Originally designed as a cement which would set slowly, allowing enough time for it to be properly laid, and a water resistant cement which could be used in construction applications where water would come in contact with the cement, Portland cement was first patented in 1824 by an English man, Joseph Aspdin, but the mix which became truly successful, and which is still used today, was designed by his son. William Aspodin in around 1843.