A. A. Michelson— Theory of the u X-RaysP 313 



are produced at the surface of the cathode, by the negative 

 charge, which forces them out from among the molecules of 

 the cathode. 



Let us now apply the tests above mentioned. 



According to this theory, an oscillatory discharge, while it 

 may be just as effective as a series of separate impulses, is not 

 essential to the formation of the vortices. The vortices being 

 forced outward from the surface of the cathode by the nega- 

 tive charge, the effect of the positive charge at the anode 

 would be to drive them in. Hence their appearance at the 

 cathode alone. 



One of the greatest puzzles connected with the behavior of 

 the X-rays is the fact that while they can pass almost unim- 

 peded through air at atmospheric pressure (let alone water, 

 glass, wood, flesh, bone, and metals) when once outside the 

 enclosure in which they are produced, they cannot even reach 

 the walls of the enclosure, except there be a very high vacuum 

 within. This problem receives a very natural solution if it be 

 considered that, in order that ether-vortices may result from 

 the electrical impulse, this impulse must be communicated to 

 them ; and must not be dissipated in the interchange of molec- 

 ular charges which accompanies, or rather produces, the dis- 

 charge at moderate or high pressures. 



As exhaustion proceeds there are fewer molecules present to 

 effect this discharge with sufficient rapidity, and as this limit is 

 approached there will be a division of the energy of the elec- 

 tric impulse between the electrified molecules and the ether- 

 vortices, and in the end all the energy of the discharge will be 

 confined to the latter. 



The reason for the non appearance of the rays under ordi- 

 nary conditions is not that the rays cannot reach the walls of 

 the enclosure or pass through them, but that they cannot form 

 at all. The propagation of vortices in straight lines, the 

 absence of interference phenomena, of reflection, refraction and 

 polarization, follow from the properties of vortices, and from 

 the absence of anything corresponding to a wave-front. The 

 passage of an ether-vortex through a mass of matter may be 

 compared with a passage of a smoke-ring through a wire gauze 

 screen or a series of such ; and as the motion of the rings is 

 more impeded the greater the diameter and the number of wires 

 per unit volume, so, the greater the number and the size of the 

 molecules — that is, the greater the density — the more effective 

 will the medium be in dissipating the energy of the ether vor- 

 tices. 



and this would lend support to the theory that this accumulation is not merely a 

 result of the negative charge, but that this excess of ether is what constitutes 

 the negative charge. 



