836 



LORD KELVIN. 



as it would be if the electric virtue of the atom were due to uniform 

 distribution tlirough the atom of an idéal electric substance of which 

 each inunitely small part repels infinitely small portions of the idéal 

 substance in other atoms, and attracts electrions, according to the inverse 

 square of the distance. But we cannot make the corresponding sujypo- 

 sition for the mutual force between two overlapping atorns; because we 

 must keep ourselves free to add a repulsion or attraction according to 

 any law of force, that we may hnd convenient for the explanation of 

 electric, elastic, and chemical properties of matter. 



§ 5. The neutralizing quantum of electrions for any atom or group 

 of atoms has exactly the same quantity of electricity of one kind as the 

 atom or group of atoms has of electricity of the opposite kind. The 

 quantum for any single atom may be one or two or three or any intégral 

 number, and need not be the same for ail atoms. The désignations mone- 

 lectrionic, dielectrionic, trielectrionic, tetraelectrionic, polyelectrionic, 

 etc., will accordingly be convenient. It is possible that the différences 

 of quality of the atoms of différent substances may be partially due to 

 the quantum-numbers of their electrions being différent; but it is possible 

 that the différences of quality are to be wholly explained in merely 

 Boscovichian fashion by différences in the laws of force between the 

 atoms, and may not imply any différences in the numbers of electrions 

 constituting their quantums. 



§ 6. Another possibility to be kept in view is that the neutralizing 

 quantum for an atom may not be any intégral number of electrions. 

 Thus for example the molécule of a diatomic gas, oxygen, or nitrogen, 

 or hydrogen, or chlorine, might conceivably have three electrions or some 

 odd number of electrions for its quantum so that the single atoms, 0, 

 N, H, Cl, if they could exist separately, must be either vitreously or 

 resinously electrified and cannot be neutral. 



§ 7. The présent usage of the désignations, positive and négative, for 

 the two modes of electrification originated no doubt with the use of , 

 glass globes or cylinders in ordinary electric machines giving vitreous 

 electricity to the insulated prime conductor, and resinous electricity to 

 the not always insulated rubber. Thus àepinus and his followers regar- 

 ded the prime conductors of their machines as giving the true electric 



