SECT, xxxvin.] GENERAL LAWS. 453 



at the rate of 200,000 miles in a second. Its action, even 

 at the distance of the sun, may therefore be regarded as in- 

 stantaneous ; yet so remote are the nearest of the fixed 

 stars, that it may be doubted whether the sun has any sen- 

 sible influence on them. 



The curves in which the celestial bodies move by the force 

 of gravitation are only lines of the second order. The 

 attraction of spheroids, according to any other law of force 

 than that of gravitation, would be much more complicated ; 

 and, as it is easy to prove that matter might have been 

 moved according to an infinite variety of laws, it may be 

 concluded that gravitation must have been selected by 

 Divine Wisdom out of an infinity of others, as being the 

 most simple, and that which gives the greatest stability to 

 the celestial motions. 



It is a singular result of the simplicity of the laws of na- 

 ture, which admit only of the observation and comparison 

 of ratios, that the gravitation and theory of the motions of 

 the celestial bodies are independent of their absolute mag- 

 nitudes and distances. Consequently, if all the bodies of the 

 solar system, their mutual distances, and their velocities, 

 were to diminish proportionally, they would describe curves 

 in all respects similar to those in which they now move ; 

 and the system might be successively reduced to the small- 

 est sensible dimensions, and still exhibit the same appear- 

 ances. We learn by experience that a very different law of 

 attraction prevails when the particles of matter are placed 

 within inappreciable distances from each other, as in chemi- 

 cal and capillary attraction, the attraction of cohesion, and 

 molecular repulsion ; yet it has been shown that in all pro- 

 bability not only these, but even gravitation itself is only 

 a particular case of the still more general principle of elec- 

 tric action. 



The action of the gravitating force is not impeded by the 

 intervention even of the densest substances. If the attraction 

 of the sun for the centre of the earth, and of the hemisphere 



