ABSTRACT
An excellent example of the illustrative fiction is furnished by the atomic theory. Observation shows that chemical combinations take place according to definite and very simple numerical relationships. Dalton propounded the theory that these simple numbers of the combining weights depended upon the atomic nature of the elements. He believed that he could best picture the striking regularity by means of a corresponding grouping of the atoms. The atomic theory often serves, in particular, to give non sensuous concepts such as force, for instance, such as chemical combinations, cohesion, and crystallization. The former attitude is of greater value in making the abstract concept of force concrete, the latter in simplifying the calculation. That is why the atoms are allowed to remain, though everything that exists has found adequate expression in the forces.
