INORGANIC EVOLUTION 23 



nebula the same force, in quantity and power, which 

 in the original nebula integrated the solid bodies and 

 their motions as they now exist? The present mathe- 

 matical method of solving this problem would perhaps 

 answer this in the negative. But this does not neces- 

 sarily imply that any of the force, or energy has been 

 lost in reality. It is continually changing from one 

 form to another. Some of it perhaps has taken forms, 

 in regions outside of the solar system. The moment 

 of momentum remains always the same, and this is the 

 product of mass multiplied by the velocity; and that 

 product again multiplied by a perpendicular drawn 

 from the center, (such as the sun), to the line of 

 direction of the moving body ; for instance, the orbit 

 of the earth. The moment of momentum, of a system 

 like the solar, is the aggregate of that of all the bodies 

 composing it. Energy is the aggregate work repre- 

 sented in phenomena. The multiplicity of effects, in 

 the process of evolution, as well as the process itself, 

 are phenomena. The energy of the solar system is 

 represented in the quantity of work which could be 

 done if all its bodies came together. The energy of 

 each of its bodies can be ascertained by multiplying 

 one-half of its mass, into the square of its velocity. 

 The persistence of force, which is the most important 

 law of physics, and is perceptible, to our senses, in 

 attraction of gravitation, molar, and molecular motion, 

 chemical attraction, in short, in the sensory perception 

 the eye has of environment, is the manifestication of 

 energy: it is the same power that theology has per- 

 sonified, and given intelligent control of phenomena. 

 Or perhaps it would be more accurate to say that the 

 first conception by man of an omnipotent power was 

 not that of natural energy, or the persistence of force, 



