Laws of the Elementary Voltaic Battery. 55 



The observations were now repeated in the reverse order, after 

 the same interval. The order was reversed, because the action of 

 the liquid in the earlier immersions is tending continually to depress 

 the permanent deflection in the succeeding ones, independently of the 

 lessened surface and must cause the final deflections to be a little 

 too low. 



By inverting the order the error is counterbalanced, the larger de- 

 flections now suffering the reduction, as we see on comparing the 

 final deflection 118, with the first permanent one 132. 



It will be seen that in nearly all our other experiments, we began 

 by immersing the slips to the greatest depth to which they were to 

 go, for the sake of making the error lean in favor of the law which 

 our investigations were opposing. 



The results here obtained, so far from agreeing with the law in 

 question, which for a ten-fold surface should have produced a ten- 

 fold deflection, are throughout at variance with it, in as much as ten 

 times the surface displayed, gives us only twice the deflection, or 

 118° to60O. 



18. So striking a departure from the supposed law, induced us to 

 investigate it by new modifications of the experiments. An old pair 

 of slips, the same which we had used before in our experiments with 

 the nitric acid solution, was therefore next employed, and using the 

 sulphuric acid solution of 1 to 94, we obtained the following. Inter- 

 vals 5 minutes. 



8 inch. 6 inch. 4 inch. 2 inch. 



1st. effect, -500° -300° -{-200° 00° 



1' -95 64 49 25 



2' 84 61 49 23 



3' 84 56 44 22 



The solution was now strengthened so as to be 1 to 60, when we 

 obtained the following deflections. 



8 inch. 6 inch. 4 inch. 2 inch. 



1st. effect, -1-300° +250^ -{-250° -250° 



V 85 72 60 40 



2' 80 67 53 33 



3' 80 66 53 30 



