500 



Mr. J. P. Joule on the Heat disengaged 



Table XI. — Experiments on the Heat evolved by the Mercury 

 Spiral in the jar of Solution of Sulphate of Zinc used in the 

 experiments of Table IX. Pile of 5 cells. 



Table XII. — Experiments on the Heat evolved by the Mercury 

 Spiral in the can of water used in the experiments of Table X. 

 Pile of 5 cells. 2 lbs. 11 oz. of water in the can. 



From the last two tables we obtain for the capacity of the jar 

 of solution used in the experiments of Table IX., 

 3-0117 41-881 . OQO „ _. Qnn 



From Tables IX. and X. we obtain for the quantity of heat 



due to . _t. x BC, 



40-869 2-3372 



"2^38~ X 2 : l248 ><J ^ 7 - i457 7 * 

 And for the actual quantity of heat evolved during electrolysis, 



^g^x 1180-9=1565°. 



