During the course of the eighteenth century important changes occurred in the conception of matter held by British natural philosophers. Historians of science have described these changes in different ways, but certain common features can be abstracted from the more recent accounts. First, there was a movement away from Newtonian matter theory, which saw all matter as the various organizations of homogeneous particles and the forces of attraction and repulsion acting between them. In place of this theory increasing favour was (...) shown towards a more empirical or ‘chemical’ approach to matter which assumed the existence of several essentially distinct types of matter each endowed with different specific qualities or properties. Second, there was an increasing tendency to accept activity as a property of matter itself rather than to ascribe it to immaterial forces. (shrink)