ELEMENTS OF STATICS AND DYNAMICS. 105 



needful as interpreters of these successive assemblages of 

 facts ; but it does not thei efore follow that they are them 

 selves to be placed among these assemblages. 



Concrete Science, made up of these five concrete sub- 

 sciences, being thus coherent within itself, and separated 

 from all other science, there comes the question Is all other 

 science similarly coherent within itself ? or is it traversed by 

 some second division that is equally decided ? It is thus 

 traversed. A statical or dynamical theorem, however simple, 

 has always for its subject-matter something that is conceived, 

 as extended, and as displaying force or forces as being a 

 scat of resistance, or of tension, or of both, and as capable 

 of possessing more or less of vis lira. If we examine the 

 simplest proposition of Statics, we see that the conception of 

 Force must be joined with the conception of Space, before 

 the proposition can be framed in thought ; and if we simi 

 larly examine the simplest proposition in Dynamics, we see 

 that Force, Space, and Time, are its essential elements. The 

 amounts of the terms are indifferent ; and, by reduction of 

 its terms beyond the limits of perception, they are applied to 

 molecules : Molar Mechanics and Molecular Mechanics are 

 continuous. From questions concerning the relative motions 

 of two or more molecules, Molecular Mechanics passes to 

 changes of aggregation among many molecules, to changes 

 in the amounts and kinds of the motions possessed by them 

 as members of an aggregate, and to changes of the motions 

 transferred through aggregates of them (as those constituting 

 light). Daily extending its range of interpretations, it is 

 coming to deal even with the components of each compound 

 molecule on the same principles. And the unions and dis 

 unions of such more or less compound molecules, which 

 constitute the phenomena of Chemistry, are also being con 

 ceived as resultant phenomena of essentially kindred natures 

 the affinities of molecules for one another, and their re 

 actions in relation to light, heat, and other modes of force, 



