552 THE POPULAR SCIENCE MONTHLY. 



Separated from all these impurities, the crystal becomes clear and 

 limpid." This experiment is especially the true image of what Fara- 

 day was as a metaphysician. For him nothing had so great a charm 

 as those serene transparent regions, in which science, cleared of im- 

 purities, appeared to his great mind in all the glory of its power and 

 splendor. He yielded himself to it with absolute abandonment. He 

 particularly loved to dwell upon the problem which is now engaging 

 us : " What do we know of an atom apart from force ? " he exclaims. 

 " You conceive a nucleus which may be called a, and you surround it 

 with forces which may be called m ; to my mind your a or nucleus 

 vanishes, and substance consists in the energy of m. In fact, what 

 notion can we form of a nucleus independent of its energy ? " As he 

 holds, matter fills all space, and gravitation is nothing else than one 

 of the essentially constitutive forces of matter, perhaps even the only 

 one. An eminent chemist, Henry Saint-Claire Deville, lately declared 

 that, when bodies deemed to be simple combine with one another, they 

 vanish, they are individually annihilated. For instance, he maintains 

 that in sulphate of copper there is neither sulphur, nor oxygen, nor cop- 

 per. Sulphur, oxygen, and copper, are composed, each of them, by a dis- 

 tinct system of definite vibrations of one energy, one single substance. 

 The compound, sulphate of copper, answers to a different system, in 

 which the motions are confounded that would produce the respective 

 individualities of its elements, sulphur, oxygen, and copper. More- 

 over, Berthelot long ago exjDressed himself in exactly the same man- 

 ner. As long ago as 1864 that savant said that the atoms of simple 

 bodies might be composed of one and the same matter, distinguished 

 only by the nature of the motions set up in it. This decisive saying a 

 great number of savants and philosophers in France and abroad have 

 repeated and are still repeating, with good reason, as the expression 

 of a solid truth. 



If the smallest parts which we can imagine and distinguish in 

 bodies differ from each other only by the nature of the motions to 

 which they are subjected, if motion alone rules and determines the 

 variety of different attributes which characterizes these atoms, if in a 

 word the unity of matter exists and it must exist what is this fun- 

 damental and primary matter whence all the rest proceed ? How 

 shall we represent it to our minds ? Every thing leads to the belief 

 that it is not essentially distinguished from the ether, and consists in 

 atoms of ether more or less strongly held together. It is objected that 

 the ether is imponderable ; but that is an unfounded objection. Doubt- 

 less it cannot be weighed ; to do that we must compare a space filled 

 with ether to a space empty of ether ; and we are evidently unable to 

 isolate this subtle agent, whose particles counterpoise each other with 

 perfect equilibrium throughout the universe. Yet many facts attest 

 its prodigious elasticity. A flash of lightning is nothing more than a 

 disturbance of equilibrium in the ether, yet no one will deny that 



