INORGANIC EVOLUTION 25 



of inorganic evolution, as is that of the nebular 

 hypothesis. The meteors are composed of the atoms 

 of universal matter, and must be compounds of simple 

 elements. They are probably formed in the suns and 

 thrown out by radiation pressure. Either theory com- 

 ports with the principles herein advocated. The theory 

 of evolution leads us to assume that the matter of the 

 universe was never homogeneous. There was no be- 

 ginning, and will be no end to phenomena. The theory 

 now seeming most plausible is that world bodies are 

 evolved from nebulae. These are produced by col- 

 lisions of celestial bodies after they have become dark 

 and cold. Such bodies may sometimes wander for a 

 hundred thousand billion years before colliding. The 

 nebula resulting from collision will have a central por- 

 tion of high density, surrounded by a gaseous envelope, 

 illuminated by the friction of its particles. The 

 violent rotation given it by the collision, together with 

 the centrifugal forces, will give a disk-shape to the cen- 

 tral mass. Meteorites, or planetesimals penetrating the 

 nebula integrate upon themselves the gaseous matter, 

 and, taking the motions of the nebula, form centers 

 of potential planets. The rotational movement, the 

 concordance of plane, and direction of it, thus ac- 

 quired in the nebula by these nascent planets will 

 remain with them for all time, with slight modification 

 of velocity, and distance from the central body. The 

 central mass will remain infinitely larger than the 

 aggregate planets evolved, and by the radiation of 

 heat, and the pressure of this radiation, will provide 

 the planets with the conditions of life. 



Nebulae are seen everywhere in space, and celestial 

 bodies are as widely distributed. Therefore all forms 

 of energy, such as heat, that are being radiated, while 



