OHM OX THE GALVANIC CIRCUIT. 409 



the lines F G and Him the portions A B and B C, composed of 

 like substance, will be inversely to each other as the areas of the 

 sections of these parts. By this the figure F G H I is now fully 

 determined. 



When the parts A B and B C of the ring have the same 

 section but are composed of different substances, the transition 

 of the electricity will then no longer be dependent solely on the 

 progressive change of electricity in each part from element to 

 element, but at the same time also on the peculiar nature of 

 each substance. This ditference in the distribution of the elec- 

 tricity, caused solely by the material natm-e of the bodies, whe- 

 ther it have its origin in the peculiar structure or in any other 

 peculiar state of the bodies to electricity, establishes a distinc- 

 tion in the electrical conductibility of the various bodies ; and 

 even the present case may afford some information respecting 

 the actual existence of such a distinction and give rise to its 

 more accurate determination. In fact, since the ring composed 

 of the two parts A B and B C differs from the homogeneous one 

 only in this respect, that the two parts are formed of two differ- 

 ent substances, a difference in the dip of the two lines F G and 

 H I will make known a difference in the conductibility of the 

 two substances, and one may serve to determine the other. In 

 this way we arrive at the following position, supplying the place 

 of a definition : In a ring consisting of two parts A B and B C!, 

 of like sections but formed of different substances, the dips of the 

 lines F G and H I are inversely as the conducting powers of the 

 two parts. If we have once ascertained the conducting powers 

 of the various substances, they may be employed to determine 

 the dips of the lines F G and H I in every case that may occur. 

 By this, then, the figure F G H I is entirely determined. The 

 determination of the conductibility from the separation of tlie 

 electricity is rendered very difficult from the weak intensity of 

 galvanic electricity, and from the imperfection of the requisite 

 apparatus ; subsequently we shall obtain a more easy means of 

 effecting this purpose. 



From these two particular cases we may now ascend in the 

 usual way to the general one, where the two prismatic parts of 

 the ring neither possess the same section nor are constituted 

 of the same substance. In this case the dips of the two parts 

 must be in the inverse ratio of the products of the sections 

 and powers of conduction. We are hereby enabled to deter- 



VOL. II. PART VII. 2 E 



