The path to the periodic table begins early in the 19th century, when John Dalton united the atomic theory of matter—which had existed in various forms, including Robert Boyle's notions, since antiquity—with the concept of the chemical element, which had emerged in the work of Antoine-Laurent Lavoisier and his followers. On the basis of his newly synthesized theory, Dalton calculated the first relative weights of atoms and compounds. Although the method for calculating atomic weights was disputed for another 50 years, in the long run atomic weights would provide the key means of organizing the elements into the periodic table.