234 PHYSICAL SCIENCE 



'* The fluid vortex atom," said Larmor, ** faith- 

 fully represents in many ways the permanence 

 and mobility of the sub-atoms of matter ; but it 

 entirely fails to include an electric charge as part 

 of their constitution. According to any aether 

 theory, static electric attraction must be conveyed 

 by elastic action across the aether, and an electric 

 field must be a field of strain, which implies elastic 

 quality in the aether instead of complete fluidity : 

 the sub-atom with its attendant electric charge 

 must therefore be in whole or in part a nucleus 

 of intrinsic strain in the aether, a place at which 

 the continuity of the medium has been broken 

 and cemented together again (to use a crude 

 but effective image) without accurately fitting the 

 parts, so that there is a residual strain all round 

 the place." 



It will be noted that any such theory, by which 

 matter, the subject of experimental mechanics, is 

 explained as an aethereal manifestation, changes 

 the point of view from which we regard mechanical 

 models of the aether itself. /Ether, being now 

 regarded as a sub-material medium, is not neces- 

 sarily described by the experimental laws to which 

 the facts of ordinary mechanics conform. In 

 dealing with the aether, we are on an entirely 

 different plane, and have no right to assume 

 that a mechanical model of its properties is 

 possible — strictly speaking, the mere statement 

 in mechanical terms of the problems involved 

 may be in itself misleading. 



However that may be, on this theory the 

 corpuscle of J. J. Thomson, the electron of Stoney, 

 Larmor, and Lorentz, was represented in the 

 aethereal world by Larmor s conception of a centre 



