413 



On the Nature of Electric Energy. 



[March 21, 



that the wave-motions of light and heat take place in an imponderable 

 highly elastic fluid medium, pervading all space, and all matter, deno- 

 minated *'8ether:" and this theory, with all its inconsistencies and incon- 

 sequences, is still in all probability generally entertained. 



That some highly elastic and attenuated medium pervades infinite space, 

 as the medium of transmission of the energies of light and heat (the very 

 main-springs of organic existence) from the centre of each solar system to 

 its dependent satellites, is a necessary consequence of the undulatory 

 theory : its existence is, in fact, demonstrated by the periodic retardation 

 of Encke's Comet. But the remainder of the hypothesis, namely that all 

 palpable matter is pervaded by sether for the purpose of transmitting 

 light- and heat-waves, is by no means equally necessary, or even tenable ; 

 for not- a shadow of evidence of the inadequacy of all matter to transmit 

 these motions has ever been produced, and in default of such evidence, the 

 contrary hypothesis is at least equally tenable : and moreover the intersti- 

 tial-cEther theory (in common with all preceding physical theories involving 

 imponderability) is burdened with grave inconsistencies. In the first place 

 the well-known phenomena of single and double refraction and polarization, 

 whether of light or heat, necessitate the somewhat violent hypothesis that 

 the elasticity of the supposed transmitting medium, aether, is not, as it is in 

 all cognizable fluids, a fixed and certain quality capable of numerical esti- 

 mation, but an ever-varying quality, depending quantitatively on the elas- 

 ticity of adjacent matter, and even varying in two or three directions within 

 the same body : it would be not more repugnant to reason to assume that the 

 elasticity of a gas is one thing in a glass bottle and another in one of brass, 

 or that the specific gravity of silver is a function of the moon's age, or the 

 melting-point of gold dependent on the sun's zenith-distance. Secondly, 

 the fundamental ideas of inertia, energy, and "work" are inseparably 

 associated with gravitation ; and it seems to imply a contradiction of terms, 

 to impute either inertia or energy (^. e. the capability of doing work) to an 

 imponderable particle, which is consequently destitute of attraction for any 

 other particle in the universe. 



The known enormous velocity (of probably not less than 250,000 miles 

 in a second) at which electricity travels through a copper conductor is 

 complete evidence that ordinary matter is capable of transmitting some- 

 thing (whether matter or motion it signifies nothing for the present 

 argument) at a considerably greater velocity than the waves of light and 

 heat ; why should not appropriate kinds of matter be assumed capable of 

 transmitting these also ? And if so, the need of the interstitial presence of 

 aether ceases altogether ; and it may with great advantage be excluded from 

 the domains of ponderable palpable matter by the very mild hypothesis 

 that it is not miscible with air, any more than oil, or palpable ether, with 

 water, but that it floats above the boundary surface of our atmosphere. 

 This hypothesis is not repugnant to reason, nor adverse to physical expe- 

 rience. On this supposition it is no longer needed to impute to aether 



