216 



Profs. W. E. Ayrton and John Perry. [Mar. 21, 



sulphate. 



Zinc sulphate 



is positive. 



Zero. 



Reading. 



Deflectic 



1083 -0 



1080 I 



2 -9 



81 '9 



82 -2 



-3 



82 '2 



80 1 



2 -1 



81 7 



82 -9 



1 *2 



82 7 



80 7 



2 '0 



82 -8 



83 -1 



0-3 



82 -5 



80 -9 



1 -6 



83 -1 



83 1 



o-o 



82 -6 



80 -8 



1 -8 



82 7 



83 -5 



0-8 



Mean 1 '3 or "033 volt, 



Distilled water and pure saturated copper sulphate (16° C). Copper 

 sulphate is positive. 



Zero. Reading. Deflection. 



1081 -6 1077 '2 4 *4 



82-1 84 7 2-6 



82 -0 78 -9 3 -1 



82 -2 84 -9 2 7 



83 -0 80 -0 3 -0 



83 "5 86 -0 2 -5 



84 -0 80 -8 3 -2 

 83 -0 85 -1 2 -1 

 82-5 79-8 . 2 7 

 82 -3 84 -8 2 -5 



Mean 2 '9 or "071 volt, 



The sulphates and metals of Table X as a Daniell, connected 

 directly to electrometer 1*068 to 1*081 volts, increasing very slowly. 



Simple cell with above zinc sulphate, 1,000 volts. An instanta- 

 neous and constant deflection. 



Simple cell with distilled water. A rapid increase in electromotive 

 force from the instant of contact of the metals with the liquid. Our 

 first reading was 0*832 volt, but there was a rapid increase when the 

 reading was being taken. 0*942 was our last reading, but there was 

 still a slow increase. 



The above copper sulphate and distilled water and the metals as a 

 Daniell. 1"060 to 1*010 volts, decreasing slowly. The same cell tried 

 again, the metals being clean, gave 0*960 to 0*951 volt. 



