TREATMENT OF ORES. 253 



by means of a partial roasting. If these materials are smelted 

 together, a matte containing all the sulphur, almost all the 

 copper, and a portion of the iron is formed. This matte can in 

 its turn be treated by a partial roasting, followed by a smelting 

 with an addition of siliceous substances. By these means, and 

 after a certain number of not at all onerous operations, a matte 

 sufficiently rich in copper for being used as an anode in an 

 electrolytic bath could be obtained. 



We are perfectly aware that our advice amounts to pro- 

 posing the use of the current for refining the copper instead of 

 using it for the treatment of natural sulphides ; this is true, but 

 it is a logical consequence of the theory of electrolysis, and it 

 is, we believe, impossible to otherwise operate in an industrial 

 installation. 



Marchese's Method. If we admitted that M. Marchese 

 applies in the works of the Societa di Miniere di Kame e di 

 Electro-metallurgia, near Genoa, the process for which he took 

 out a patent in 1883, and which is essentially based on the 

 anodes obtained by the compression of the copper ore in metallic 

 cases, we should have to alter our opinion, for the results are, it 

 appears, satisfactory. But we know from a letter, published by 

 the Director of the works in * La Lumiere filectrique,' that, 

 with the view of notably reducing the resistance of the circuit 

 in the electrolytic baths, the mode of formation of the anodes 

 has been altered. 



It is useless to discuss the object of this change ; it suffices 

 us to know that the anodes are no longer formed with natural 

 ores without roasting and a previous fusion, to be satisfied and 

 to believe in the financial success of the undertaking, and 

 particularly if the ores contain small quantities of gold and 

 silver. 



Lambert's Method. This process particularly relates to the 

 treatment of gold and silver ores. The ore is dissolved by 

 nascent chlorine, the latter being itself obtained by the de- 

 composition of a soluble chloride under the action of an electric 

 current. The metals of the ore are thereby transformed 

 into chleride, and are dissolved in the bath, either in virtue of 

 their own solubility, or owing to the salts which enter into the 



