ELECTROCHEMISTRY 155 



scale; antimony, bismuth, tin, platinum, zinc, and even 

 iron can be thus refined; the field is very inviting to the 

 experimenter and to the technologist, and is rapidly in- 

 creasing in industrial importance. 



Metal Plating: All electro-plating is done by the use 

 of electrolytic methods similar to those just described. If 

 we imagine the impure metal anode replaced by pure metal, 

 and the receiving cathode to be the object to be electro- 

 plated, we have before us the electro-plating bath ready 

 for action. Everybody knows the value and use of gold, 

 silver, and nickel plating; less well known are platinum, 

 cadmium, chromium, zinc, brass, and bronze plating. These 

 are among the oldest of the electrochemical industries. E'lec- 

 trotyping is only a variation of this work ; also the electro- 

 lytic reproduction of medals, engravings, cuts, etc., and 

 even the production of metallic articles of various and 

 complicated forms, such as tubes, needles, mirrors, vases, 

 statues, etc. There is opportunity here to hardly more 

 than catalog these various branches of electrometallurgical 

 activity. Pittsburg people will be interested, however, 

 in knowing that many of the newer buildings in this city 

 contain thousands of feet of electrical conduits zinc plated 

 in splendid fashion by electrolysis, at a works within a 

 few miles of this city. At McKeesport, tubes are coated 

 by dipping into melted zinc, on an immense scale, but the 

 electrolytic method is gaining a foothold, and we may live 

 to see all galvanizing in reality practised as it is spelled. 

 The removing of metallic tin from waste tin scrap is also 

 accomplished on a large scale by the application of similar 

 principles. It is being operated at a distance from Pitts- 

 burg, but your open-hearth furnaces use up annually 

 thousands of tons of the scrap steel thus cleaned and saved 

 for remanufacture into useful shape. 



Without having mentioned or described more than a 

 fraction of the electrolytic methods in actual industrial 

 use, I hope that I have made clear the importance and 

 extent of this kind of electrochemical processes. Assum- 



