Intelligence and Miscellaneous Articles. 545 



again into gunpowder, while the grains of shot will rush towards 

 the muzzle of the gun, and crowd into its breach. 



It is of importance to observe that, under the new conditions 

 of the universe, all true dynamical laws will remain the same as at 

 present, but many quasi-dynamical laws will be reversed. Thus, 

 the first law of thermodynamics — the law of the equivalence of 

 energy — will remain unaltered, but the second law will become its 

 converse. Instead of a warmer body tending to impart heat to a 

 cooler body, as at present, the new condition of things will tend to 

 make their temperatures more divergent. Heat will become 

 mechanical energy directly, and without requiring the accom- 

 panying degradation of energy which now takes place. Friction, 

 instead of retarding the progress of bodies, will help them forward. 

 The air, instead of impeding a missile passing through it, will 

 urge it on. And, when reviewing a system so divergent from 

 what we find in the actual universe about us, it is very instructive 

 to bear in mind that the universe, under the new conditions that ive 

 suppose, would be as perfect a dynamical system as the actual universe 

 is. This places before the mind in a very strong light the grave 

 error which is too often made when such laws as I have referred 

 to — the second law of thermodynamics, &c. — are supposed to be 

 true dynamical laws. 



This naturally leads up to the consideration whether the laws 

 of causation would be affected. Those relating to true causes 

 would not be affected : those relating to quasi-causes would all be 

 inverted. True causes never precede their effects ; they are always 

 strictly simultaneous with them. The science of Dynamics recog- 

 nizes true causes only. All change of the motion of a body is in 

 that science attributed to forces acting while the change is taking 

 place ; and the persistence of a body in motion while no forces are 

 acting on it is due to the inertia of the body, i. e. the body itself is 

 the cause of it. It is because the inertia of a body is a sufficient 

 cause for its continuing in motion that time can elapse between 

 events in nature. Whether the motion changes or does not 

 change, the effect and its true cause are accurately simultaneous. 

 The dispute as to whether action takes place at a distance does not 

 disturb this statement. Every one who does not suppose that the 

 sun attracts the earth from a distance and without lapse of time, 

 supposes that some medium pervading the intervening space com- 

 municates the action ; and it is not the distant body, but the sur- 

 face of this medium where it touches the body acted on, that upon 

 this view can alone be recognized in the science of Dynamics as the 

 true immediate cause of the changes of motion of the second body. 

 Thus, in all cases, dynamical effects arise along with, and not 

 after, their causes. But in popular language, and indeed in all 

 but very carefully strict language, many events are spoken of as 

 caused by events that have preceded them. Thus, in the usual 

 loose way of talking, we may speak of a ball's having been re- 

 acted on by the ground as the cause why it is now ascending, 

 although a moment's reflection would show that, iu strict lan- 

 guage, the reaction of the ground has caused only those changes 



Phil Mag. S. 5. Vol. 23. No. 145. June 1887. 2 P 



