KINETIC THEORIES OF GRAVITATION. 215 



Keplerian tbird law being however maintained. Thus the vortex sur- 

 vived its primary purpose and function. The small centrifugal motion 

 of the matter of the second element contained in the celestial vortex is 

 sufficient to make it denser at the outer than at the inner portion, thougb 

 leaving it still too rare to sensibly affect the motions of the outer 

 planets.* 



The primal element collected and condensed at the center of each vor- 

 tex forms a star or sun, though neither the cause nor the manner of such 

 condensation is very clearly unfolded. This central mass agitated with 

 intestine motions of extreme violence in all directions, as in a boiling 

 caldron, produces an intense light and heat, while detached particles at 

 the surface, continually more and more broken up by the frequency and 

 impetuosity of their collisions, acquire a subtilty transcending all con- 

 ception of the imagination, and are finally thrown off in all directions 

 with explosive force to immense distances, and with the velocity known 

 as that of radiant light. These infinitely small particles, forming the 

 luminous "effluvias" incessantly springing from the sun in radial lines, 

 pass without obstruction through the pores or interstices of the grosser 

 matter forming the planets, though losing at their surface their luminif- 

 erous property. 



Beyond the orbit of Saturn they encounter more and more of a similar 

 material collected at the outer confines of the vortex ; and, while a large 

 number pass into adjacent vortices and continue their course unimpeded, 

 a large number suffer collision by direct impacts from the similar radia- 

 tions from these vortices. Being inelastic they are mutually arrested, 

 and form molecules of various size, according to the number of such col- 

 lisions suffered, until impelled by the resultant of these impacts, they 

 either pass into adjoining vortices or back into their own in the form of 

 material molecules of the second element, with correspondingly reduced 

 velocities, t 



" In this manner we conceive there must continually descend from the 

 heavens a copious and impetuous rain of pellets, driven inward by the 

 shocks of molecules from surrounding vortices." This converging or cen- 

 tripetal shower of pellets, called the " central torrent," perpetually de- 

 luging the sun, forms the compensation and nourishment for its cease- 

 less waste, as the evaporated water condensing into raindrops replen- 

 ishes the constant waste of the sea. These minute balls, having only the 

 amount and direction of motion imparted to them at the boundaries of 

 the vortex, are yet supposed to fall with mathematical precision toward 

 the center of the sun without ever touching each other as they approach. 

 ^Notwithstanding the efforts expended by the author in attempting to 

 establish this necessity, this centripetal directness undoubtedly remains 

 physically the weak point of his hypothesis. 



As the inter-vortical molecules acquire differen t magnitudes before 



* Loco citat., sectious xviii, six, pp.278, 279. 

 \Lococitat., sec. xxviii-sxxvi. 



