420 



Dr. G. Grore on a New Method and 



This curve shows : — 1st. That the electromotive force varies 

 with the temperature. And 2nd. That a regular variation of 

 temperature of the solution is attended by an irregular change 

 of -electromotive force. It is probable that the curve obtained 

 by varying the temperature is characteristic of the substance, 

 and would be different with every different substance and 

 degree of strength of its solution. 



In a similar experiment with a solution of '027 grain of 

 chloride of ammonium in 465 grains of water, the electro- 

 motive force of the zinc-platinum couple remained constant 

 at -9084 volt at all temperatures between 14° and 100° C, 

 and then very slightly increased. 



D. Curve by Varying the Temperature of the Solution 

 at One Metal only. 



In these measurements the large bent glass tube was em- 

 ployed (see section " B "). The liquid consisted of 39 grains 

 of potassium chloride dissolved in 465 grains of previously 

 boiled distilled water. In one series of measurements the 

 zinc was immersed in the heated portion of liquid and the 

 platinum in the cold portion : and in the other series the 

 reverse. The following are the curves obtained :— 



Fig. 21. 

 Curves of KC1 Solution. 



Zn varied. 



Centigrade £ g 

 degrees. 





