ELECTROPLATING 



489 



In the preceding experiment the copper solution is de- 

 composed by the electric current as it passes through the 

 solution from the' copper strip to the lead strip, and the 

 copper freed from 

 the compound is de- 

 posited on the lead. 

 Just as fast as cop- 

 per from the solution 

 is deposited on the 

 lead strip, the same 

 amount of copper is 

 dissolved from the 

 copper strip; and so 

 the strength of the 

 solution is main- 

 tained as long as 

 there is any of the 

 copper strip remain- 

 ing. If it were de- 

 sired to plate with 

 silver, a silver strip 

 would have to be 

 substituted for the 

 copper strip and a 

 solution of a suitable 

 silver compound sub- 



AN ELECTROTYPE 



Photograph of the plate from which page 15 

 of this book is printed. 



stituted for the 



per sulphate solution. 



Whatever the metal used for plating, corresponding solutions 



would have to be used. All gold, silver, nickel, and other 



plating is done in this way. 



This book, like all books made in large numbers, has 



