SECTION III. 



ELECTRO-DEPOSITION. 



CHAPTER VIII. 



NICKEL-PLATING. 



Electro-deposition Nickel Physical Properties Chemical Properties Heat 

 due to the Formation of Double Salts Nickel-plating Preparation of the 

 Bath Nickel Baths Auxiliary Baths Preparation of Pieces for Nickel- 

 plating Nature of Anodes Modus operandi Electromotive Force of 

 the Current Treatment when taken out of the Bath Renickeling 

 Duration of the Baths Vats Nickel-plating of Zinc Powell's Process 

 Deposition of Nickel by Single Immersion. 



ELECTRO -DEPOSITION. -^Electro -deposition, or electroplating, 

 is the ensemble of means used for the reproduction or the coating 

 of objects by means of the electric current. In the first instance 

 it is especially used for the reproduction of artistic works and 

 typographic engravings, and in the second for silvering, gilding, 

 nickeling, and coppering a large number of decorative objects 

 of general use. 



The industry of metallic coating or plating being the most 

 important branch of electro-depDsition, we will deal with that 

 first, commencing with nickel, the success of which has been 

 steadily growing during the last few years, in Europe as well as 

 in the United States of America. 



NICKEL. It will be advantageous before describing the opera- 

 tions required in order to obtain a good coating of nickel to give 

 some information respecting this metal as yet very little known, 

 and which is destined, in a very near future, for applications as 



