Table 254. 



COMPOSITION AND ELECTROMOTIVE FORCE OF BATTERY CELLS. 



The electromotive forces given in this table approximately represent what may be expected from a cell in good work- 

 ing order, but with the exception of the standard cells all of them are subject to considerable variation. 



(a) Double Fluid Batteries. 



Name of 

 cell. 



Chromate 



Daniell* 



Grove 



Negative pole. 



Solution. 



Bunsen . . Amalgamated zinc 



Marie Davy 



Partz 



( I part H2SO4 to / 

 I 12 parts HoO . J 



12partsK.2Cr.2O7 

 to 25 parts of 

 H2SO4 and 100 

 parts H2O . . 



{ I part H2SO4 to I 

 I 12 parts H2O . ) 



( I part 1X2804 to ) 

 i 4 parts H2O . ) 



( I part II2SO4 to > 

 I 1 2 parts H2O . J 



( 5% solution of I 

 \ ZnS04 + 6H2O ( 



Positive 

 pole. 



Carbon 



I part NaCl to | 

 4 parts H2O . i 



( I part H2SO4 to ) 

 ( 12 parts H2O . ) 



Solution of ZnS04 



( H2SO4 solution, ) 

 I density 1.136 . ) 



( H2SO4 solution, 1 

 ( density 1.136 . \ 



{H2SO4 solution, 1 

 density 1.06 . ) 



( II2SO4 solution, ) 

 I density 1.14 . ( 



( H2SO4 solution, ) 

 ( density 1.06 . ) 



NaCl solution . . 



j I part H2SO4 to ) 

 I 12 parts H2O 5 



Solution of MgS04 



Copper 



Solution. 



Fuming H2NO3 

 HNO3, density 1.38 



( I part H2SO4 to / 

 I 12 parts H-iO . ) 



1 2 parts K2Cr207 |^ 

 to 100 parts HoO \ 



j Saturated solution ( 

 ( ofCuSOi+sHiO^ 



Platinum 



Carbon 



Fuming HNOs . . 



HNO3, density 1.33 



Concentrated HNOs 



HNOs, density 1.33 



HNO3, density 1.19 



" density 1.33 



( Paste of protosul- ) 

 ; phate of mercury > 

 ( and water . . . ) 



Solution of K2Cr207 



W.E 



1.94 

 1.86 



2.00 



2.03 

 1.06 

 1.09 

 1.08 

 1.05 



1-93 

 1.66 



1-93 



1.79 



1.71 



1.66 



1. 61 

 1.88 



1.50 



2.06 



* The Minotto or Sawdust, the Meidinger, the Callaud, and the Lockwood cells are modifications of the Daniell, 

 and hence have about the same electromotive force. 



Smithsonian Tables. 



246 



