AEPINUS ATOMIZED 



BY 



Lord KELVIN. 



§ 1. According to the well-known doctrine of Aepinus,, commonly 

 referred to as the one-fluid theory of electricity, positive and négative 

 electrifications consist in excess above, and deficiency below, a natural 

 quantum of a fluid,, called the electric fluid, permeating among the 

 atoms of pondérable matter. Portions of matter void of the electric 

 fluid repel one another; portions of the electric fluid repel one another; 

 portions of the electric fluid and of void matter attract one another. 



§ 2. My suggestion is that the ÂEPiNus'fluid consists of exceedingly 

 minute equal and similar atoms, which I call electrions, *) mu ch. smal- 

 ler than the atoms of pondérable matter; and that they permeate freely 

 through the spaces occupied by thèse greater atoms and also freely 

 through space not occupied by them. As in AEriNiis' theory we must 

 have repulsions between the electrions; and repulsions between the 

 atoms independently of the electrions; and attractions between electrions 

 and atoms without electrions. For brevity, in future by atom I shall 



l ) I ventured to suggest this name in a short article published in n Nature" 

 May, 27, 1897, in which, after a slight référence to an old idea of a „one-fluid 

 theory of electricity" with résinons electricity as the electric fluid, the follow- 

 ing expression of my views at that time occurs: „I prefer to considei v an 

 „atomic theory of electricity foreseen as worthy of thought by Faraday and 

 „Clerk Maxwell, very definitely proposed by Helmholtz in his last lecture to 

 „the Royal Institution, and largely accepted by present-day workers and tea- 

 „chers. Indeed Faraday's law of electro-chemical équivalence seems to neces- 

 „sitate something atomic in electricity, and to justify the very modéra name 

 ^électron. The older, and at présent even more popular, name ion given sixty 



