COMPOUND CELL PROCESS. 



impure as not to be fit to melt and roll again, but it may be used in 

 the composition of common brass. Mr. De la Eue, in a communi- 

 cation to the Chemical Society, 1 gives the results of several analytical 

 experiments upon scrap zinc. Before distillation the scraps usually 

 give the following results in 100 parts: 



Zinc . . . 

 Mercury . . 

 Dross and loss 



67.3 

 4.3 



28.4 



100.0 

 The composition of the zinc left after distillation is given as 



Zinc 90. 



Iron 2.56 



Lead 6. 



Copper 1.44 



100.00 



Compound Cell Process. Another method of economizing power 

 was proposed in what is termed the compound cell system, by which 

 it was said that the electricity passing through a series of cells would 

 be able to produce the same quantity of work in every cell with no 

 more cost. This plan may be stated thus : 



A is a Smee's battery ; the wire z is conducting the electricity to the 

 compound trough which is composed of a series of water-tight cells, 

 as a a, and is connected with a piece of copper c, forming a positive 

 electrode ; in the same cell, and facing this electrode, is a medal, 

 connected by a copper wire to a piece of copper placed in the second 

 cell, opposite which is another medal connected in the same manner 

 with another piece of copper, and so on through the series, which 



1 Memoirs and Proceedings of the Chemical Society, Vol. ii. page 393. 



