344 Mr. J. J. Waterstou on the Integral of Gravitation, 



gravity, cohesion, &c., viewed in their dynamic aspect as con- 

 forming to impulses derived from elastic impact. 



§ 15. 

 Destruction and Reproduction of Force in Nature is apparent, 

 not real. 



In the mutual action of bodies there is an apparent destruc- 

 tion and reproduction of force, but the more such phsenomena 

 are investigated experimentally with respect to their quantita- 

 tive elements, the more reason there is to believe that the disap- 

 pearance and reappearance are merely transference from one 

 agent to another, and are as exactly regulated as the communi- 

 cation of force by impact in the preceding examples. 



Even if we had not those proofs of the existence of a universal 

 medium that the undulatory theoi-y of light supplies, it would 

 be well to admit the existence of media to which ordinary mat- 

 ter may be assumed to be entirely subordinate in all their poten- 

 tial relations, so as to give order to our ideas in tracing out the 

 dynamical sequence of nature. It would be taking too narrow 

 a view if we limited the function of the luminiferous sether to 

 the conveying of physical pulses only. The atmosphere also 

 conveys physical pulses, but that is the least important of its 

 functions in the economy of natm'e. There is nothing that 

 should hinder us attributing to the media concerned in the ra- 

 diation of heat and light, the higher functions of electric polarity 

 and gravitation. The special dynamic arrangements by which 

 this is effected may ever elude research, but as there is no limit 

 to the vis viva which such media may conserve in their minutest 

 parts, so there is no physical impossibility in that vis viva being 

 suddenly transferred to the molecules of ordinary matter in the 

 proportions and sequence required to carry out the order and 

 system of nature. 



The fundamental principle of action in such media must be 

 in accordance with elastic impact, for upon that the dynamic 

 theory of heat and conservation of force rests as a foundation. 

 The statical and dynamical characteristics of gravitation and 

 transfusion of force have also been shown to conform to it, so 

 that all the forces that hold the molecules of bodies together 

 must also be in subjection to it. 



Force issues from such media and becomes apparent in ordi- 

 nary matter as vis viva. Force disappears from ordinary matter, 

 and being transferred to the media, becomes non-apparent or 

 latent. When we raise a weight from the ground, we give force 

 (A) to the agent of gravitation; when we let fall the same weight, 

 we take force (B) from the agent. Directing attention to the 

 mode of raising the weight, we inquire where was A before it 



