•with Formula for ascertaining its power. 26 1 



thosewhowere engaged in experimentseither in the construction 

 of the voltaic battery itself or in complex resistances, found it 

 perfectly inapplicable. By the equation for (W) we find that 



W 



A = -p — p- which I have already mentioned must be deter- 

 mined before we can 'find the value of I' A, or what is properly 

 called the power of any battery. 



Sometimes W is very small, as in De Luc's columns, where 

 the total amount of chemical action, although in) is frequently 

 500 to 1000, is so small, that experimenters have even denied 

 its existence ; but when we consider that these very persons 

 assert, that as soon as chemical action does become decidedly 

 manifest, the action ceases, how strongly do they favour our 

 views ! for, according to our equation, we expect (a) to be 

 gradually increased till all action would be stopped. W, in- 

 deed, according to our equation, might be so small, as not to 

 be cognizable to our senses for weeks, months, years, or cen- 

 turies ; and yet (I) multiplied by a very large (n) would show 

 enormous intensity or power of overcoming resistances. 



The present modifications of the theory of galvanism are 

 perfectly consonant with every practical direction given in the 

 preceding pages, and the only difference in the theory will 

 be found irt the uncertainty expressed upon the contact and 

 chemical action theories. Indeed, in page 54< of my work, 

 as already cited, the result is almost given in words though 

 not in letters. By removing the slight difficulties which ap- 

 peared to envelope the latter theory, by showing the necessity 

 for a negative pole to cause power is unfounded, the beautiful 

 doctrine of Faraday is placed on the surest foundation, and 

 the extraordinary and dogmatical paradox of a power without 

 a cause is proved to be a fanciful chimaera. 



With regard to the connexion of the voltaic power with 

 that of electricity produced from other sources, perhaps it 

 might be expected I should say a few words. In the voltaic 

 battery (I) is small, but may be increased to any size by (n), 

 and as we have the power of increasing (A) also unlimitedly, 

 we can perform any amount of work per second, indeed we 

 might throw down hundreds of tons of copper per second, if 

 we were disposed to make our circuit large enough. In 

 frictional electricity (I) is enormous, but (A) is depressed to its 

 utmost limit, so that not having a perfect command over (A) 

 to increase it indefinitely, we cannot at present obtain what 

 work we please in a given time. In animal electricity (I) is 

 great, (A) is moderately large. In thermo-electricity (I) is 

 depressed, perhaps increasingly, so that although (A) and (n) 

 may be multiplied indefinitely, yet, practically, we should never 

 be able thoroughly to overcome the smallness of (I). In that 



