CHAPTER XVIII 



ELECTROLYTIC DISSOCIATION 



THE earliest indications of the electrical character 

 of matter were obtained from studies of the conduction 

 of electricity through solutions. To-day we know that 

 such conduction is essentially a mechanical process of 

 transferring electrons. In order that a medium which 

 has no dislodged electrons shall serve to transfer 

 through itself electricity, there must be brought about 

 and maintained an abnormal electronic condition for 

 some of its molecules. Normal molecules will not so 

 serve. 



This abnormality can only occur if the molecule is 

 dissociated into parts which are abnormal. If there 

 are thus formed two components they must depart 

 equally but oppositely from normality, that is, they 

 must be equally and oppositely charged. Even then 

 conduction can occur through such a medium only if 

 the abnormal particles are free to move, as would be 

 the case if the medium were a liquid. Now pure 

 liquids like water, alcohol, or hydrochloric acid are 

 non-conductors. Solutions of substances which are 

 chemical compounds, frequently but not generally, 

 are conductors. Those which conduct are called 

 electrolytes or sometimes "ionogens." 



The simplest dissociation would be that in which a 



244 



