  However attractive the reduction of the material world to particles interacting by way of forces may have appeared, it must be recognised that there was scant empirical support for the idea. This point is clearest in the context of chemistry. The affinities presumed to act between chemical ‘atoms’ were postulated solely on the basis of the observed chemical behaviour of bulk substances manipulated in the laboratory. The assumption that the chemical behaviour of bulk substances were due to combining atoms added nothing that made a difference to what was testable by experiment. Observed properties of chemical substances were simply projected onto atoms. Newtonians had not formulated a chemical atomic theory that could be used as a basis for the prediction of chemical phenomena at the experimental level.  Newton's optics was in an analogous situation. However, here it can be said that that optical theory was able to accommodate a range of optical phenomena in a coherent way that rendered it superior to any rival. The result was the widespread acceptance of the theory in the eighteenth century.