Pictographic symbols used at the beginning of the 19th century to represent chemical elements and compounds. They are similar to those of the ancient alchemists. The discovery of more elements during the 18th century brought many attempts to devise a chemical nomenclature, and in 1787 the French chemists Jean-Henri Hassenfranz and Pierre-August Adet published the scheme of symbols illustrated here. However, it was superseded by the modern alphabetic notational system devised by Berzelius introduced in 1814 which soon became generally accepted.