Glass has many properties and, because of this, enjoys much symbolic importance. It results from the perfect alliance of the four so-called ‘pure’ elements: earth, fire, water and air. Our knowledge of the material was largely empirical prior to the advances made in the field of chemistry in the eighteenth century. The secret business of glassworks, which were initially situated deep in forests, and the glassmaker’s ability to transform matter through fusion, only added to the mystique.