1873.] Messrs. Gladstone and Tribe on an Air-battery. 251 



The results may be thus exhibited : — 



Proportion of surfaces. 



Deflection. 



Silver. 



Copper. 



Expt. I. 



Expt, II. 



Expt. III. 



1 



0-25 



24 



23 





1 



0-5 



28 



27 





1 



0-75 



81 



30 





1 



1-0 



33 



32 



28 



1 



1-33 







28 



1 



2-0 







32 



1 



4-0 







30 



The increase of the copper surface, therefore, has comparatively 

 little effect. 



Proportion 



of surfaces. 



Deflection. 



Copper. 



Silver. 



Expt, I. 



Expt. II. 



Expt. HI. 



1 



0-25 







7-5 



1 



0-5 







16 



1 



0-75 







21 



1 



m 



33 



32 



28 



1 



1-33 



41 



40 





1 



2-0 



56 



54 





1 



4-0 



96 



92 





The increase, therefore, of the silver or negative metal causes an 

 almost proportionate increase in the chemical action. This, doubtless, 

 arises from the necessity of oxygen, and explains the value of the large 

 surface exposed by the silver crystals in the tray. 



The effect of heat on the action of this cell was examined; it 

 increases the action greatly : thus an arrangement which gave a deflec- 

 tion of 40 at 20° C. gave one of 250 at 50° C. ; and the augmentation was 

 observed to be much more rapid in the higher than in the lower portions 

 of this range of temperature. 



If the formula given above for the reaction be a true one, it follows 

 that every atom of copper deposited on the silver in the state of suboxide 

 must be compensated by an atom of copper dissolved from the copper 

 plate. This was proved quantitatively. In a cell that had been in 

 action for a week the loss of the copper plate was 0'391 grm,, while 



