384 



ELEMENTARY LESSONS ON [CHAP. xi. 



417. General Laws of Electrolytic Action. In 



addition to Faraday's quantitative laws given in Art. 211, 



the following are 

 important : : 



(a.) Every 

 electrolyte is de- 

 composed into 

 two portions, an 



_/^ anion and a ka- 



tion, which may 

 be themselves 

 either simple or 

 compound. In 

 the case of simple 

 binary com- 

 pounds, such as 

 fused salt (Na 

 Cl), the ions are 

 simple elements. 

 In other cases 

 the products are 

 often complicat- 

 ed by secondary 

 actions. It is 

 even possible to 

 deposit an alloy 

 of two metals 

 brass for example 

 from a mix- 

 ture of the cya- 

 nides of zinc and 

 of copper. 

 (b.) In binary compounds and most metallic solutions, 



the metal is deposited by the current where it leaves the 



cell, at the kathode. 



(c.) Aqueous solutions of salts of the metals of the 



alkalies and alkaline earths deposit no metal, but evolve 



Fig- 155- 



