1888.] Development of Electricity by Atmospheric Oxidation. 189 



ferent aeration plates : thus the following mean readings were 

 obtained. 



Increment in E.M.F. brought about by increasing the Strength of 

 Caustic Soda Solution from ra!Sra 2 O,100H 2 O to nNa 2 O,100H 2 O. 





m = 1 -75. 



m = 3 45. 



m — 1 "75. 





n = 3 -45. 



n = 7 -15. 



n = 7 15. 





0-033 



0-015 



-048 





0-029 



-004 



033 





0-014 



0-032 



0-046 





0-019 



0-027 



0-046 



Gold foil 



0-031 



o-oio 



0-041 





0-027 



0-016 



-043 





0-032 



0-007 



0-039 





0-029 



o-ooi 



0-030 



Combining these figures with the average values previously obtained 

 for 3'45Na 2 O,100H 2 O, the following mean values result. 



E.M.F. of Cells set up with Amalgamated Zinc and m!MTa 2 O,100H 2 O. 





m = 1 -75. 



m = 3 -45. 



m = 7-15. 





1-599 



1-618 



1-645 







1-563 









1-484 







1-334 



1-463 



1-467 





1-416 



1-448 



1-455 





1-416 



1-443 



1-459 





1-399 



1-428 



1-429 





1-395 



1-426 



1 -436 





1 -390 



1-423 



1-438 





1-382 



1-396 



1-428 







1-326 





Cells set up with Caustic Soda Solution and Various Kinds of Aeration 

 Plates opposed to Lead. 



It was found that when a given aeration plate had attained to a 

 condition of steadiness, if opposed to a piece of freshly brightened 

 pure lead, somewhat irregular readings were obtained for a few 

 minutes owing to the effect of the alkali on the polish of the lead ; 

 in a short time, however, this disturbing influence mostly subsided, 

 and tolerably constant values were obtained for two or three hours, 

 after which a slight lowering generally began to be noticed con- 



