242 ELECTROLYSIS. 



another opening at the top allowed the flowing in of the weak 

 solution. In one of these boxes was placed the metal intended 

 for the reception of the copper deposition, and between each of 

 them were the cast-iron plates intended for the production of 

 the current. The apparatus was regulated in such a manner, 

 that at every instant as much concentrated solution of copper 

 and weak solution of iron were admitted as weak copper liquor 

 and strong iron liquor run out; this. action continued without 

 any manipulation. The only labour required consisted in taking 

 away the copper sheets when they were of a suitable thickness, 

 and replacing the cast-iron plates when they were used up. 



Without stopping to consider the lead ore, which Becquerel 

 treated in a similar manner, we will quote, word for word, the 

 conclusion at which he arrived after ten years of ingenious 

 researches, experiments, and combinations respecting the electro- 

 chemical treatment of a great variety of ores. 



BECQUEKEL'S CONCLUSION. "From the facts set forth in 

 this book," he says, in his 'Traite d'^lectricite,' published in 1855, 

 "it evidently results that silver ores can be treated without 

 difficulty by the electro-chemical process when sea-salt is 

 at a low price and there is enough wood in the locality for 

 operating a roasting, if the chloruretting cannot be done by the 

 wet process ; that this process is particularly applicable to very 

 complex ores, that is to say, sulphuretted ores; and that, 

 although it is simpler than the Mexican or freyberyan amal- 

 gamation, there are, nevertheless, instances in which it will be 

 preferred to this last method, which would not be suitable for 

 the treatment of argentiferous galena and argentiferous cuprous 

 pyrites. It is most probable that the electro-chemical method 

 by means of which silver, copper, and lead ores can be treated, 

 will be adopted in practice when the principles upon which it 

 rests shall have become familiar. It will more particularly 

 be adopted in countries where mercury is only found with 

 difficulty, and where wood is too scarce for treating the ore 

 by smelting and where common salt is abundant." 



This conclusion, which nine years later was republished with- 

 out any alteration by the author in his ' Traite d'filectro-chimie,' 

 can be thus summed up : the electro-chemical process for the 



