254 Mr 4 Smee's Nexv Definition of the Voltaic Circuit, 



battery the hydrogen acts upon nitric acid, forming water, 

 and setting deutoxide of nitrogen, &c. free ; but in this case 

 the intermediate part between the combination of the first 

 element and the removal of the second, is only the atom of 

 hydrogen ; it therefore follows that this action must be re- 

 garded as nothing but a series of little local batteries, or atomic 

 circles, having nothing to do with the great battery which we 

 make available for our purposes. 



It is absolutely essential, according to our definition of the 

 voltaic force, that to be enabled to apply this principle for any 

 purpose, however small a quantity of the force may be re- 

 quired, that either (c) or (r) should possess a capability of 

 being so far prolonged as to enable us, with the imperfect 

 powers that nature has furnished us, to handle or deal with 

 these intervening portions of the circuit. 



In the principal batteries now in use, their relative powers 

 and attributes may be fully understood by considering each of 

 the above properties in their construction. 



F. a. c. r. e. 



Grove large small small medium little. 



Daniell large small small most much. 



Smee large small small small much. 



Smooth platinum large small small small enormous. 



Thus the four batteries may be considered equal in the 

 properties of the F, a, c, the differences being only in (r) and 

 (e). In Grove's the (e) is so small as not only to compensate 

 a slight increase in the (r) over mine, as usually constructed, 

 but to give a great advantage to his form of battery. In 

 DanielFs the (e) is perhaps rather smaller than in mine, but 

 that is more than counterbalanced by (r) being larger in 

 Daniell's than in mine. The effect of these properties are, 

 that F in Grove's is diminished but little, F in mine more, in 

 Daniell's more still; and in the smooth platinum battery by 

 far the most. Thus is explained the decomposition of dilute 

 sulphuric acid between platinum plates, by one cell of Grove's 

 battery, and the same result not being obtained by the others. 

 This equation is not only valuable for batteries, but applies to 

 every single case where any substance acts upon a compound 

 fluid in such a way as first to decompose it, then to combine 

 with one of its elements, and set free in some way the other. 

 Thus, if potassium be cast into dilute muriatic acid, (F) is im- 

 mensely large, potassium having a violent affinity for oxy- 

 gen; («) is exceedingly small, potash being readily soluble in 

 water; (r) is almost nothing, only one atom of fluid being 

 traversed by the force; (c) is practically nothing from the 



