72 THE GENESIS OF WORLDS. 



consider these subjects more fully because it is the purpose of 

 this article to inquire chiefly concerning the forces that would be 

 engaged in such a process of evolution ; and firstly, how from 

 the preponderance of the repellent forces holding matter in uni- 

 versal diffusion, there came the final mastery of the aggregating 

 forces ever concentrating, combining, and working up the mate- 

 rials of the universe. 



The first of the operations which comes to our notice in 

 the progress of this evolution is the condensation of the gases. 

 This according to all experience ought to evolve heat ; but in- 

 stead, we find only that the flow of the currents the motion of 

 the masses is proportionately increased. Is there a connection 

 of cause and effect between these phenomena? 



All motion that we are familiar with requires the expenditure 

 of heat. The combustion of coal supplies motion to the steam-en- 

 gine. The evaporation of water by the sun's heat causes the rain- 

 clouds and the mill-streams. The oxidation of certain elements 

 in the food we eat is the combustion which supplies our bodies 

 with power of motion. Recent discoveries have shown, not only 

 that motion is heat transformed, but that to produce a certain 

 quantity of motion an invariable certain quantity of heat is re- 

 quired. 



Again, the cessation of motion evolves heat. It is well known 

 that by skillful blows with the hammer a cold iron bar can be 

 made red-hot. Two wheels revolving in opposite directions and 

 touching at the circumference, become highly heated ; and fac- 

 tories have been warmed solely by this transfer of motion into 

 heat. Friction is but another name for the arresting of motion, 

 and as we well know always produces heat. There is also here 

 the same equivalence as in the other case. The stoppage of mo- 

 tion evolves just the amount of heat that was required to pro- 

 duce that motion. 



The greatest triumph of modern science is the splendid in- 

 duction that all the forces are correlative and indestructible. Not 

 an impulse of motion, of light, or heat, or any force, is ever lost. 

 It may be communicated from one body to another, or transmu- 

 ted into some other form of force, or become for a time latent 



