1883.] the Electromotive Force and Resistance of Batteries. 



in the observations may have caused the non- coincidence between 

 the two parts. 



It follows from these experiments that changes of temperature do 

 not practically affect electromotive forces, but that they materially 

 affect the internal resistances, of cells. Faraday's observation is fully 

 confirmed, while Daniell's mistake is easily understood if he employed, 

 as he probably did, a galvanometer of low resistance. 



It also follows that of the various forms of batteries in practical 

 use the Daniell is most seriously influenced by variations in tempera- 

 ture, and that in all experiments with that battery, either the tempe- 

 rature must be kept constant, or frequent measurements should be 

 taken of its internal resistance and allowance made for the variation. 



