79 6 THE POPULAR SCIENCE MONTHLY. 



of attraction and bombardment would be the void focus of the disk, 

 toward which the resultant of all the forces in the ring would tend, as 

 a corollary from the deduction from synchronism that the force which 

 binds the atomic couples varies directly as the distance, instead of as 

 the inverse squares. 



In its passage through the disk-atom the ray takes up and conserves 

 the dropped motion as a transverse vibratory motion of some kind ; or, 

 as Maxwell styles it, " some vector property which does not interfere 

 with the motion of translation" (" Encyclopaedia Britannica," ninth edi- 

 tion, article " Ether "), and which it can impart again to the revolving 

 systems of atoms through which it travels, in an inverse mode to that 

 of its derivation. The invention of the mechanism of this vector 

 motion has its difficulties. I consider, first, that the radiant energies 

 are not exhibited in matter, except upon a certain degree of disturb- 

 ance, showing itself in a violent clashing of systems, either from the 

 forming of new combinations or from incandescence resulting from 

 the accession of energy from without or within. These clashings dis- 

 turb the equilibrium of the atomic orbits, and occasion their rapid 

 deformation by harmonic vibration in elliptic orbits whose rectangular 

 axes rapidly alternate from major to minor while the agitation is kejDt 

 up. Now, the circular movements of the components do not disturb 

 the uniform transit of the linear ray ; but the rapid approach and 

 recession of the components in passing through the violent elliptical 

 transitions cause a rapid alternation of stress in the field of stress 

 through which the rays pass since the stress varies as the distance of 

 the components causing a vibratory deflection of the stream of par- 

 ticles, due to the variation of the attractive force, in all rays except 

 the polar ray, and in the plane of the ray normal to the plane of stress. 

 Since the disk-atoms lie in all planes, we shall have transverse vibra- 

 tions in all directions ; but, if the rotating disk is gyratory, as would 

 be the rule and not the exception, the identical ray would receive a 

 vector or corkscrew motion, similar to what is called for by observation. 

 The amount of deflection I take to be the index of refraction of the 

 molecule. 



It may seem unaccountable that the whole ray should undulate 

 from passing through a single locality of oscillatory disturbance, be- 

 ing composed of discrete and unconnected particles ; but we may com- 

 pare the parallel phenomenon of a jet of water, forcibly ejected to a 

 great distance through a hose-nozzle, which exhibits to the eye similar 

 undulations when the source of discharge is slightly and rapidly oscil- 

 lated. 



It may also seem incredible that any orbital movements could be 

 permanent enough to sustain oscillatory vibrations of such inconceiv- 

 able frequency as those which luminous rays are known to execute ; 

 but I have computed, from the probable dimensions of the hydrogen- 

 molecule as assigned by the molecular physicists, and an orbital veloci- 



