216 KINETIC THEORIES OF GRAVITATION. 



being finally driven toward the center of any system, they will also have 

 differing- rates of descent, "their velocities being inversely as their 

 masses, so that if one should become a thousand times larger and slower 

 than the impelling particle of light, it would still have a velocity equal 

 to the diameter of the earth in one minute;" and the average speed 

 would be much greater than this, though always much less than the 

 velocity of light. " The central torrent with such a velocity would ex- 

 pend its force on any body which it encountered ; and this is precisely 

 the gravitation of the planets toward the sun." And as the various 

 sizes of the minute balls would permit them to penetrate the pores of 

 gross matter to varying depths before being arrested, their impulses 

 would be distributed through the mass instead of being entirely expended 

 on the surface.* 



The particles of light radiated by very distant stars, having to run the 

 gauntlet of all the intermediate stellar vortices, might be supposed to 

 bo very much obstructed and reduced in number, if not in some cases 

 entirely suppressed. 



Each planet and satellite has its subordinate vortex, in which the 

 same play of impalpable effluvia and returning torrent is carried on; 

 and although this is treated as a very obvious corollary of the system, 

 it is one somewhat difficult to fully formulate or realize. Whether two 

 independent masses of lead or iron also attract each other impulsively 

 by virtue of their own special vortices, with atomized radiations and 

 resulting central torrents, is not so definitely made out. 



Such then is the primum mobile of the planetary gravitations; and 

 with an admirable complacency, Bernouilli contrasts the system of 

 Newton with his own, in which the elementary particles of matter, having 

 no pores, receive the gravitative impulse necessarily on their surfaces. 

 •' Now if it were the essential nature of bodies to 'attract' each other, 

 it is evident that elementary particles would gravitate in proportion to 

 their solidity, and not in the ratio of their surface, and that .... 

 consequently their attraction should diminish in the ratio of the cubes 

 of the distance, instead of as the squares. . . . What then becomes 

 of the system of ivl. Newton, when its very foundation is tumbled into 

 ruins 'J I am surprised that not one of the partisans of this hypothesis 

 has perceived this incongruity, in attributing attraction as an essential 

 quality, not only to large masses, but even to the elementary particles 

 destitute of pores ! " t 



It is scarcely necessary to criticise this wonderful system of "Celestial 

 I'hysics." The condensation of the impalpable atoms of caloric, without 

 adhesions and without attractions, (and seemingly without inertia,) into 

 the dynamic graviflc molecules of the "central torrent," is a phenomenon 

 certainly as recondite as the gravitation these molecules are summoned 

 to impel. It is sufficient to say that the Nouvelle Physique satisfies no 

 single condition of the six formerly indicated as essential prerequisites. 



"Loco cital., sec. xxxvii-sl. i Loco citat.,sec. xlii, p. 299. 



