Jöns Jacob Berzelius was a Swedish chemist who studied medicine at the University of Uppsala and was a professor of chemistry in Stockholm.  He drew on the ideas of both Davy and Dalton to create an electrochemical view of how elements combined together.  Berzelius classified elements into two groups, electronegative and electropositive depending which pole of a galvanic battery they were released from when decomposed.  He created a scale of charge with oxygen being the most electronegative element and potassium the most electropositive.  This scale signified that some elements had positive and negative charges associated with them and the position of an element on this scale and the elements charge determined how that element combined with others.  Berzeliuss work on electrochemical atomic theory was published in 1818 as Essai sur la théorie des proportions chimiques et sur linfluence chimique de lélectricité.  He also introduced a new chemical nomenclature into chemistry by representing elements with letters and abbreviations, such as O for oxygen and Fe for iron.  Combinations of elements were represented as sequences of these symbols and the number of atoms were represented at first by superscripts and then later subscripts.