4. PHYSICAL SCIENCE 



atom, or group of atoms, of the substance in 

 solution, associated with a positive or negative 

 electric charge ; it moves through the liquid 

 under the action of an applied electric force, 

 and gives up its charge to the electrode — that 

 is, the terminal by which the current enters or 

 leaves the liquid. The conduction, instead of 

 being conceived as a river flowing uniformly, 

 must figuratively be represented as taking place 

 by the passage of discrete quantities of electricity; 

 in much the same way as water is sometimes 

 carried from a lake to a burning house by means 

 of a chain of bucket-bearers. 



By the application of similar conceptions, the 

 passage of electricity through gases has received 

 a convincing explanation. Differences appear, 

 but the fundamental ideas are the same in the 

 two branches of the science of electrolytic conduc- 

 tion. It is, however, in the newer side of the subject 

 that the most striking results have been obtained. 

 Electrolysis in liquids had suggested the concep- 

 tion of ultimate units of electricity — atoms of 

 electricity, analogous to the atoms of matter. 

 Gaseous conduction enabled these electric atoms 

 to be isolated, separated from their attendant 

 material atoms, and studied independently. 



Great has been the revelation which followed. 

 The isolated atoms of negative electricity — the 

 electrons, as they have been named by Stoney — - 

 have been identified by the work of Thomson, 

 Lorentz, and Larmor, with one of the physical 

 bases of matter, with the corpuscles, or sub- 

 atoms, by means of which, combined in varying 

 numbers and in different arrangements with a 

 more essential positive nucleus, are composed 



