148 E. F. ROEBER 



established chemical industries. The outcome of the war be- 

 tween the old chemical and the new electrochemical methods 

 has been a victory for the latter, although the financial returns 

 have been comparatively small, on account of the demorali- 

 zation of the market. 



While in the production of caustic and chlorine the pur- 

 pose is to separate and maintain separated the anodic and 

 cathodic products, just the reverse is the case when we want 

 to obtain bleaching liquors or hypochlorites, since they are 

 produced by the reaction between the chlorine and caustic. 

 For this purpose it is evidently necessary to have the elec- 

 trodes near together and to aid the above reaction by stirring. 

 Several forms of hypochlorite apparatus are in use abroad, 

 but have not yet found any extended use in this country. By 

 modifying the conditions of operation, it is possible to produce 

 chlorate, the main points being the use of a moderately high 

 temperature and precaution for preventing reduction. This 

 example shows how completely the results of a reaction may 

 be changed, by varying the conditions, and it emphasizes the 

 necessity, pointed out above, of carefully maintaining the 

 original conditions of the system unchanged during electroly- 

 sis, if we invariably want to get the same results. 



In electroplating, the problem is to have always a suffi- 

 cient number of the metallic ions to be deposited in close 

 proximity to the cathode. The tendency of the current is 

 to impoverish the solution near the cathode. This tendency 

 must be counteracted. Stirring the solution and revolving 

 the electrodes are suitable means and care must be taken 

 to obtain proper corrosion of the anode which has to supply 

 new metallic ions to replace those deposited at the cathode. 

 There are now more than 1,200 electroplating establishments 

 in the United States and in recent years a tendency has man- 

 ifested itself to give up the old rule-of-thumb methods and to 

 work according to exact principles. 



Of much greater industrial importance, however, is 

 the kindred art of electro-refining. In 1879 an experimental 

 copper refining plant was in operation for a short time at 

 Phoenixville, Pa., but the first commercial copper refining plant 

 in America was erected in the early '80's. This is the Balbach 



