Conductors of Electricity, and during Electrolysis. 273 

 the resistance of wire. I have shown, (55.) that the cur- 

 Fig. 6. 



402 W R 3-15 

 A , + 1 B 1°-9Q. 



Fig. 5. 



r 2-83 R 3-15 

 C , h . D 1°9Q. 



rent 1 0, 9 Q would pass against the resistance A B. But we 

 know that 1°*9 Q was also passed when the cell and the battery 

 formed the sole opposition (52.), and that on account of the 

 resistance to electrolyzation, the virtual battery intensity was 

 then one-sixth less, and hence that only five-sixths of the re- 

 sistance represented by A B could have been opposed in this 

 case, in order to the passage of the same current. Draw, 

 therefore, another line, C D, one-sixth less than A B, and it 

 will represent this resistance ; from which, on subtracting 

 R 3*15, we have r 2*83, the true resistance to conduction of 

 the decomposing apparatus. 



. . (1*9) 3 



58. From (28.), and the data above given, we have -,- , 2 



20' 

 X 2*83 X 7 0, 56 x -—f = 7°'29, the theoretical result. 



59. I made three other experiments with the same elec- 

 trodes, and with the same battery. The results of these with 

 those of the experiment just given at length, are as fol- 

 lows : — 



Experimental. Theoretical. 



Exp. 7. 7-26 7°29 



Exp. 8. 8-12 8«32 



Exp. 9. 10-2 10-2 



Exp. 10. 9*64 9-75 (Refitted battery.) 



Mean 8*8 8-89 



60. Exp. 11. — The mean current o, 846 Q from a battery 

 often zinc-iron pairs, was, by means of the same electrodes, 

 sent through two pounds of dilute sulphuric acid for half an 

 hour, during which the correct heat that was generated was 

 3 0, 09. 



61. In order to find the true resistance to conduction of 

 the decomposing cell, it was necessary to remember that in 

 this instance one-third of the intensity of the ten pairs was 

 expended in overcoming the resistance to electrolyzation of 

 the water. With this exception the calculations were made 

 precisely as before, and gave 3*76, the resistance of the cell ; 

 whence we have the theoi'etical heat 2°*88. 



Phil. Mag. S. 3. Vol. 19. No. 124. Oct. 1841. T 



