DEPOSITION OF VARIOUS METALS. 183 



RUSSELL AND WOOLRICH PROCESSES. Messrs. Russell and 

 \\oolrich recommend the following brass bath: 



Brass Bath. 



Cupric acetate 3730 grammes. 



Zinc acetate .. 370 



Potassic acetate 3730 



Dissolve the above substances in 25 litres of hot water, and 

 add some cyanide until the formation of a precipitate, which is 

 dissolved in an excess of reagent. Maintain an excess of 

 cyanide in the bath. Use either one brass anode, or at the 

 same time, two anodes, one of brass, the other of copper. 



BRUNEL'S PROCESS. M. Brunei prepares his solution in 

 the following manner : 



Brass Bath. 



Cupric chloride 373 grammes. 



Potassic carbonate 9325 



Zinc sulphate 746 



Ammonic nitrate 4660 



Dissolve the chloride in 2 25 litres of water, the carbonate 

 in 27 litres of water, the zinc sulphate in 2 25 litres of hot 

 water. Mix these solutions. Add the ammonic nitrate, and 

 mix again very intimately. Add some cold water to make 

 50 litres. 



Another formula : 



Potassic carbonate 3730 grammes. 



Potassic cyanide 570 



Zinc sulphate 466 



Cupric chloride 310 litres. 



Water .. .. , 56 



Prepare separately the various solutions. Add to the zinc 

 sulphate and to the cupric chloride a part of the dissolved car- 

 bonate. Dissolve the precipitates which are formed by adding 

 ammonia; introduce the remainder of the potassic carbonate 

 and the cyanide, and complete with water. 



NEWTON'S PROCESS. Mr. Newton has prepared various 

 solutions for obtaining the deposition of copper, tin, and zinc 

 alloys. 



