214 WALKS AND TALKS. 



XXXVII. THE WHIRLING KIRK-MIST. 



NEBULAR THEORY OF WORLD ORIGIN. 



BEHOLD the matter of a solar system in the form of a I 

 nebula. Poised in the midst of space, it tends to a globular) 

 form ; but the attraction of its own center is so distant as to 

 be feebly felt at the remote periphery of so tenuous a mass. 

 The late accessions of nebulous stuff have left superficial irreg- 

 ularitieslike those in the clouds which float in our atmos- 

 phere. They subside with comparative slowness; but yet they 

 tend to disappear. This vast empire of world-stuff rotates, I 

 but a million of years may flee away before one revolution is ' 

 completed. With eternity at command all finite intervals of 

 time are zero. I can not answer the question whether a gas- I 

 eons constitution pervaded all parts of this nebula. I think 

 it probable that portions of the included space were filled with 

 gas. I think such portions may have been bounded by the/ 

 sphere on which the elasticity of the gas was equalized by oppo&f 

 ing attractions. There was already fire-mist fine liquid par- 

 ticles suspended in gases or poised between counter attractions. 

 There were probably stones and concretions of iron hanging I 

 suspended through the mass. It is not at all supposable that the 

 entire space within the periphery of the nebula was occupied. 

 There may have been spaces hundreds or thousands of miles 

 wide, not filled with any thing but the all-pervasive ether if 

 that exists. I do not conceive a continuous medium so unim- 

 aginably thin as would result from the expansion of the mat- 

 ter of the solar system uniformly through a sphere bounded 

 by the orbit of Neptune. 



If this mass is heated, it radiates heat into surrounding 

 space, and the heated parts contract. If the parts are still 

 gathering themselves nearer to the distant center of gravity, the 

 whole mass contracts. If the time ever arrives when the 

 parts gathering toward the center of gravity are balanced by 

 mutual resistances, or by reaction of heat, then further loss I 

 of heat will result in contraction of the whole mass. In 

 either event, the mass contracts. If a rotating body contracts, j 



