1892.] 



Voltaic Cells with Fused Electrolytes. 



77 



tion of the two chlorides with each other affects the electromotive 

 force of the cell. It is impossible to answer this question without 

 further data of various sorts. The small irregular variations from 

 theory shown in the tables may possibly be due to some action of 

 this kind. The results of experiment show, however, that these few 

 complications have but a small effect ; very much less than those of 

 the aqueous form of cell with its metals coated with oxide and 

 hydrogen films, and its mixture of two or more electrolytes and dis- 

 solved oxygen, such as might perhaps be represented as 



Zinc + ZnO + H | ZnCl 2 + H 2 O + O j MgCl 2 + H 2 + O j Magnesium + MgH 2 O 2 + H, 



which seems to be too complicated for exact calculation. 



In arranging the practical details, care was taken to keep the 

 metals as clean as possible, the contacts good, the electrolytes fused 

 but not boiling, and the temperatures fairly equal at the two metals ; 

 also to prevent, as far as possible, the two chlorides from diffusing 

 into one another. After trying various arrangements, that of which 

 fig. 1 represents about half the actual size was adopted. 



Fig. 1 



A V-tuke A of hard glass, formed as shown, and supported by its 

 longer limb, contained one of the chlorides, in which dipped the 

 wire or strip of appropriate metal C. The bend of this tube was 

 heated as required by one or two Bunsen burners. Into the shorter 

 limb was inserted the other tube B, its lower end contracted some- 

 what, and filled with a plug of asbestos, to act as a porous partition. 

 This smaller tube contained the second chloride, with its appropriate 

 metal D. When the metal represented by C was fusible at nearly 



