Laws of the Elementary Voltaic Battery. 



43 



The slips being new, as fresh surface was successively plunged, 

 an increased action generally took place, which however soon decli- 

 ned ; and each column of observations shews a general tendency lo 

 declension. 



4. To make the comparison at shorter intervals of time, and thus 

 avoid any declension which might arise from a long period of expo- 

 sure, — the following were made. 



Zinc 4 in. cop. dipped to, 



1 in. 52° 



2 in. 68 



3 in. 70 



4 in. 82 



Copper 4 in. zinc dipped to, 



1 in. 50° 



2 in. 65 



3 in. 58 



4 in. 60 



Diff. 52 and 82=30 



The same repeated gave the following. 

 Z. 4 in. cop. 



1 in. 25° 



2 in. 47 



3 in. 52 



4 in. 57 



DifF. 50 and 60=10 



Cop. 4 in. zinc. 



1 in. 45° 



2 in. 51 



3 in. 53 



4 in. 54 



57-25 = 32 



54-45=9 



Thus it would appear that when the copper surface is increased 

 from 1 to 4 inches, the zinc remaining constant at 4 inches, the in- 

 crease of activity in the battery is between three and four times as 

 great as when the zinc surface is increased in the same proportion. 



Subsequent experiments will shew that the above mode of compa- 

 ring the effects of the two metals is less correct than that adopted 

 afterwards, since the successive immersions oi fresh portions of the 

 plate produces an effect greater than the normal power of the sur- 

 face immersed when long in action. We should here observe that 

 throughout our experiments, whenever any portion of the plates was 

 drawn out of the solution the moistened part was carefully wiped 

 dry ; — otherwise a slight action in the surface newly exposed would 

 have made all the smaller deflections somewhat too great, and would 

 thus have modified the series by an error which would have tended 

 against the law. 



5. In all the foregoing experiments one of the surfaces is made to 

 increase until it equals the other, but never to exceed it. It was 

 thought however of importance, to examine the case where the va- 



