440 OHM ON THE GALVANIC CIRCUIT. 



changes occur in a constant form, are therefore of the highest 

 importance for testing this assumption : for if the conclusions 

 drawn from the supposition are thoroughly confirmed by those 

 phjenomena, it is admissible, and may then be applied without 

 any further consideration to all analogous researches, at least 

 within the same limits of force. 



We have assumed, in accordance with the obser^-ations hitherto 

 made, that when by any two exteriorly like constituted elements, 

 whether they be of the same or of different matter, a mutual 

 change in their electi-ical state is produced, the one loses just so 

 much force as the other gains. Should it hereafter be shown 

 bv experiments that bodies exhibit a relation similar to that 

 which in the theory of heat is termed the capacity of bodies, 

 the law we have estabhshed m ill have to undergo a slight altera- 

 tion, which we shall point out in the proper place. 



4. When the two elements E and E' are not of equal magni- 

 tude, it is still allowed to regard them as sums of equal parts. 

 Granting that an element E consist of m perfectly equal parts, 

 and the other E' of m' exactly similar parts, then, if we imagine 

 the elements E and E' exceedingly small in comparison with 

 their mutual distance, so that the distances from each part of 

 the one to each part of the other element are equal, the sum 

 of the actions of all the m' parts of the element E' on a part of 

 E will be m' times that which a single part exerts, and the sum 

 of all the actions of the element E' on all the tn parts of E wiU 

 be OT m' times that which a part of E' exerts on a part of E. It 

 is hence e^•ident, that in order to ascertain the mutual actions 

 of dissimilar elements on each other, they must be taken as pro- 

 portional not merely to the difference of their electroscopic forces 

 and their duration, but also to the product of their relative mag- 

 nitudes. We shall in future term the sum of the electroscopic! 

 actions, referred to the magnitude of the elements — by which 

 therefore we have to understand the force multipUed by the 

 masnitude of the space over which it is diffused, in the case 

 where the same force prevails at all places in this space — the 

 quantity of electricity, without intending to determine anything 

 therebv with respect to the material nature of electricity. The 

 same observation is applicable to all figurative expressions intro- 

 duced, without which, perhaps for good reasons, our language 

 could not exist. 



In cases where the elements cannot be regarded as evanescent 



