OF THE PASSIVE FORCES. 209 



tory movements of the aether of a translative character. This he 

 supports by mathematical reasonings which cannot be entered 

 on, but the gist of them is that the atoms are driven together 

 or asunder by waves, which, as it were, beat more on one side 

 than the other, and thus push and keep them together or 

 asunder by this perpetual impact. In this manner we may 

 imagine the attractive forces of chemical attraction, cohesion, 

 and gravitation, and the repulsive force of heat to be produced 

 by movements of something, though not of the atoms which 

 are here passive. The common statement that when a weight 

 is raised the force or energy required to raise it becomes poten- 

 tial, and is again transformed into actual energy when the 

 weight is let go and it falls to the earth, is a mere statement of 

 the fact, and so far from being an explanation, it almost univer- 

 sally induces the belief that some attractive power is accumu- 

 lated in the weight itself or the earth which pulls it back. 

 Whereas by the above hypotheses of translative sethereal waves, 

 the body is merely placed in a position in which, having dis- 

 tance to traverse, it can take on as actual movement in space, 

 the motions constituting the force of a given quantity of the 

 sethereal gravitation waves, which are thus extinguished (like 

 the luminous waves in the dark lines of the solar spectrum) in 

 the process of pushing the falling body and the earth together. 

 In this manner, whether the theory be true or false, we can 

 form an idea how something of the nature of motion can be 

 expended in the apparent attraction of gravitation. The above 

 two fundamental hypotheses may be disputed, and are dis- 

 puted, and people are not content to accept them as beyond 

 the province of speculation at all events. But there are no 

 alternative speculations on the aether which do not leave quite 

 as much to be postulated, and if we object to the hard, round, 

 spherical atoms, and prefer the idea ;of permanent vortex 

 motions in a frictionless fluid, we can suppose these acted on by 

 translative waves in the same way. 



In visiting Manchester, long before seeing a similar 

 remark by Dr. Carpenter, I have often been struck by 



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