70 DIVISIBILITY OF MATTER ATOMIC THEORY, 



mentary difficulties, which here, as so often elsewhere, 

 stand stubbornly in our way. The word Motion itself 

 is one of these. No conception of it can be formed 

 which does not include relation to something else than 

 the atom, or aggregate of atoms, moved a relation 

 so complex as regards the matter of forces in action, 

 that all conclusions must be accepted with reserve. If 

 we suppose compound forces acting in this invisible 

 world of monads and the condition is a very ad- 

 missible one rotatory motions would be the probable 

 result ; and such hypothesis is, in truth, more appli- 

 cable than any other. 



Leaving this speculation, we come again to what 

 may be regarded as the integral or necessary proper- 

 ties of ultimate atoms. To those of infinite minuteness 

 and mobility may further be added that of definite 

 figure a postulate almost essential to any interpreta- 

 tion we can put upon them as components of matter 

 the only key to the phenomena of definite proportions, 

 isomorphism, substitution, and all besides which consti- 

 tutes chemical science. It is impossible to suppose 

 that atoms, shapeless and indeterminate in figure, can 

 be instrumental in changes and combinations deter- 

 minate as mathematical facts. Adaptations so perfect 

 and constant can only co-exist with primitive forms 

 equally perfect and permanent. But admitting these 

 premises, what system of atomic morphology can be 

 constructed to meet the conditions of the problem? 

 More than sixty kinds of matter are still elementary to 

 our knowledge. Are we to suppose different configura- 

 tion of the component atoms of each of these, and of 



