68 Mr. H. Wilde on the Indefinite Quantitative 



many thousand tons of pure copper are produced annually, 

 slabs of crude copper containing gold and silver are sus- 

 pended in a number of electrolysing vessels containing a 

 nearly saturated solution of copper sulphate. Plates of 

 thin sheet copper are also immersed in the solution, 

 opposite the slabs of crude copper. A number of these 

 electrolytic vessels, ranging from 50 to 140, according to 

 different economical conditions, are coupled up in series ; 

 the crude copper constituting the anodes, and the thin 

 plates the cathodes of the arrangement. When an electric 

 current from a dynamo-electric machine is transmitted 

 through the series of vessels, the crude copper is dissolved in 

 the solution, and deposited in a pure state on the thin plates. 

 The gold and silver alloyed with the crude copper are 

 precipitated as insoluble deposits, and recovered subse- 

 quently by well-known metallurgical processes. 



In the application of the principle of indefinite electro- 

 lysis to the refining of copper by quantities of electricity 

 indefinitely small, it will be obvious that an indefinitely 

 large amount of metallic copper and sulphate solution 

 would be required ; but, in order that the amount may be 

 reduced to the limits of commercial practice, powerful 

 dynamo-electric machines, absorbing some hundreds of 

 horse-power, are employed in many establishments. The 

 immense scale on which this process is now conducted in 

 various parts of the world masks, in no small degree, the 

 principle of indefinite electrolysis on which the economic 

 value of the process depends, and may account for the 

 principle being so little recognised by scholastic science. 

 Hence from the like cause we may have the anomalous 

 spectacle of learned professors demonstrating the law of 

 definite electrolysis, and the definite magnetic action of 

 electric currents, as absolute and universal truths, by 

 means of copper conductors produced through the prin- 

 ciple of indefinite electrolysis, and by the use of dynamo- 



