MODEL OF POSITIVE ION 301 



in the form of very rapid vibration. If there are 

 certain free periods in the atom, then in the 

 transformation downwards of the rotations of the 

 electron the radiation will become intense as it 

 passes through these periods. Thus we arrive at 

 an explanation of the results of experiments that, 

 speaking generally, the spectrum of the fluorescent 

 light is independent of that of the exciting cause, 

 so that when ultra-violet light falls upon a fluores- 

 cent body the association or dissociation produced 

 is accompanied by radiation in the same part of 

 the spectrum, whatever the wave-length of the 

 exciting light. 



This model will lead us in search of forms of 

 radiation of a very penetrating kind from the 

 positive ion, as doubtless free periods of very high 

 frequency exist in the molecule to which the 

 intrinsic energy of a positive ion will most 

 effectively yield, as in the emanation from thorium 

 oxide and radium bromide. 



The phosphorescent molecules in a phosphores- 

 cent gas will not carry a free charge so long as 

 they are radiating, and will radiate in virtue of 

 the close proximity of the negative corpuscles. 

 The molecular agglomerations are an indispensable 

 part of the process in attracting the corpuscles so 

 as to liberate the potential energy of the atoms 

 composing them, which if scattered at comparatively 

 great distances do not accomplish the associations ' 

 with the same facility. 



