494 Mr. T. S. Moore on the 



Results:— {!) Cu, CuS0 4 , ZnS0 4 , Zn. (DanielPs cell.) 



K. 



4000... 



6000... 



12000... 



r (direct ex- 

 periment). 



r (reverse 1 -p. 



(calculated). 



(observed). 



1 

 (calculated). 



ohms. 

 1389 



1401-2 



13800 



ohms. volt. 

 1392 8135 



| 

 1389 0-8885 



1378 ! 0-9819 



volt. 

 0-8135 



0-8895 



9835 



volt. 

 1-3405 



1-2740 



1-1935 



volt. 

 1-3397 



1-2736 



1-1937 



For this cell D = 1*096 volt, B = 2*0434 volts. 



The second column of the above was calculated from the 

 observations by means of formula (a), the third column by (c), 

 the fourth by (6), and the sixth by (d). The value of r used 

 in the formulae (b) and (d) was 1388*2, the mean of the six 

 values obtained above. 



In this experiment (and in all following) the copper electrode 

 was electroplated and the zinc electrode cleaned with emery- 

 paper and dilute sulphuric acid. 



(2) Cu, CuS0 4 , CdS0 4 , Cd. 



r (direct 

 E. 1 experi- 



, men'). 



r (reverse 

 experi- 

 ment). 



(observed). 



(calculated). 



,3 



(observed). 



D 2 



(calculated). 



volt. 



•8068 



•7878 

 •7654 



4000... 



6000... 



12000... 



ohms. 

 11496 



1128-6 



1118-4 



ohms. 

 1150-6 



11511 



1168-0 



volt. 

 0-5740 



0-6220 



0-6760 



volt. 

 0-5746 



0-6206 



06746 



volt. 

 •8070 



•7880 



•7660 





For this cell D = 0*739 volt at 14° C, B = 1-0434. 

 Mean value for r = 1144*4. 



The cadmium used was a rod prepared by Johnson and 

 Matthey, and was warranted to be over 99 per cent, cadmium. 

 It was cleaned before each experiment by emery-cloth and 

 dilute sulphuric acid. 



