Recovery of Copper from Its Solution in Mine Drainage. 327 



Table B. — Analyses of the principal 

 constituents of Ballygahan Water 

 before and after Cementation, in 

 partsper 100,000,by G. A.Kinahan. 



Table C— Analyses of the Mine 

 Waters of Schniollnitz before and 

 after Cementation, in Vienna, lbs. 

 per cub. ft. : by Lill von Lilienthal. 



Table D. — Analyses of the Lixivium and Cement Copper at Agordo 

 by M. de Hubert. 



Note added in Press. — October 16th, 1882. 



From Dr. C. W. Siemens' Address to the British Association, 1882. 



"The deposition of metals from their solutions is perhaps the oldest of 

 all useful applications of the electric current, but it is only in very 

 recent times that the dynamo current has been practically applied to' 

 the refining of copper and other metals, as now practised at Birmingham 

 and elsewhere, and upon an exceptionally large scale at Ocker, in 

 Germany. The dynamo machine there employed was exhibited at the 

 Palis Electrical Exhibition by Dr. Werner Siemens, its peculiar feature 

 being that the conductors of the rotating armature consisted of solid 

 bars of copper 30 mm. square, in section, which were found only just 

 sufficient to transmit the large quantity of electricity of low tension 

 neccessary for this operation. One such machine consuming 4-hoi-se 

 power, deposits about 300 kilogrammes of copper per 24 hours ; the 

 motive power at Ocker is derived from a waterfall." 



