REFINING OF COPPER AND LEAD. 205 



on each side with cotton cloth and filled with copper shots, was 

 placed. This frame divided the bath into two parts. Under 

 the action of the current the silver and the copper dissolved in 

 the dilute sulphuric acid ; the copper of the frame precipitated 

 the dissolved silver, and the copper only was deposited on the 

 cathode, which was also of copper. 



This process at first sight seemed somewhat complicated, 

 and particularly when it was completed by conical revolving 

 cathodes facilitating the gaseous escape; but M. Andre, whom 

 we went to see at Frankfort, affirmed to us that he thus 

 obtained economical results. 



There unhappily are very few data respecting the processes 

 in use in various factories for the electrolytic treatment of 

 copper. The various manufacturers have devices of their own, 

 their own compositions of baths, and their own methods for con- 

 ducting the whole of the operation. The difficulty of protect- 

 ing oneself against infringements prevents the manufacturers 

 from taking out patents ; on the other hand, they keep their 

 means of production to themselves, and do not allow anybody 

 to inspect their establishments. This certainly does not con- 

 tribute to the rapid development of the electro-chemical science, 

 but it is easy to understand that for a manufacturer or a com- 

 mercial concern, private interests are stronger than public 

 benefit. 



Though not in a position to give details respecting all the 

 large manufactories, we can give some information about the 

 installations of M. Hilarion Eoux, at Marseilles, and about 

 the Elliott Metal Company's Works at Selly Oak, near 

 Birmingham. 



M. HILARION Koux's WORKS. Mr. Mather has installed, 

 at Marseilles, for M. Hilarion Eoux, a small copper refining 

 plant, of which the following are the particulars : 



Number of baths 40 



Total surface of anodes ... . . . 900 square metres. 



Surface of anode per bath 

 Number of plates per bath 

 Length of the plates 

 Width of the plates 

 Thickness of the plates . . 



22-50 



115 



0-C8 metre. 



0-15 



0-01 



