312 MR. THOMAS CARRICK ON THE 



These three states of matter, thus constituted, would 

 necessarily be in stable equilibrium at the respective sur- 

 faces of normal contact — the fluid matter having no pro- 

 perties tending to disturb the equilibrium of the mole- 

 cular structure of the solid matter, on the one hand, or 

 of the gaseous matter on the other, and the gaseous 

 matter bearing like inoffensive relation to the fluid matter, 

 on the one hand, and to the surrounding nebulous matter 

 of space on the other. 



The force exerted upon such a sphere of condensed 

 nebulous matter by another of like origin would, there- 

 fore, in virtue of the laws of condensation, act, firstly, 

 through and by the intermediation of the atoms of the 

 difiused nebulous matter of space, thence through and by 

 means of the molecules of gaseous matter, and thence 

 through and by means of the molecules of fluid matter to 

 the solid nucleus beneath — each of these varying states of 

 matter thus forming an indispensable link in the un- 

 broken chain by and through which one cosmical body 

 is related to another and to space. 



It must needs be admitted that this mode of viewing 

 the action of the force of gravitation dififers widely from 

 that indorsed by modern writers on physical astronomy, 

 in whose works space is treated as a vacuum, so far as 

 ponderable matter is concerned. Such was not the faith 

 of the great founder of the laws of gravitation ; for, in his 

 third letter to Bentley, Newton explicitly states that " the 

 idea of one body acting upon another at a distance thi'ough 

 a vacuum, without the mediation of anything else, by and 

 through which their action and force may be conveyed to 

 one another, is to him so great an absurdity that he 

 believes no man, who has in philosophical matters a com- 

 petent faculty of thinking, can ever fall into.'^ 



In the laws of gravitation, the motions of the heavenly 

 bodies are proposed as a mechanical problem ; and it is 



^ 



