OHM ON THE GALVANIC CIRCUIT. 421 



perty of galvanic circuits, representing, as it were, their entire 

 nature, had akeady been noticed long ago in various bad con- 

 ducting bodies, and its origin sought for in their peculiar con- 

 stitution * ; I have, however, enumerated in a letter to the editor 

 of the Annalen der Physikf, the conditions under which this 

 property of the galvanic circuit may be observed, even in the 

 best conductors, the metals ; and the necessary precautions, 

 founded on experience, by which the success of the experiment 

 is assured, described in it, are in perfect accordance with the 

 present considerations. 



A (a) 

 The expression y- . -jj-, denoting the dip of any portion of 



the circuit, vanishes when L is indefinitely gi*eat, while A 

 and jj^ retain finite values. Consequently, if L assumes an in- 

 definitely great value, while A remains finite, the dip of the 

 straight Unes representing the separation of the electricity, in 

 all such pai-ts of the circuit, whose reduced length has a finite 

 ratio to the actual length, vanishes, or what comes to the same 

 thing, the electricity is of equal force at all places of each such 

 part. Now, since L represents the sum of the reduced lengths 

 of all the parts of the circuit, and these reduced lengths evi- 

 dently can only assume positive values, L becomes indefinite as 

 soon as one of the reduced lengths assumes an infinite value. 

 Further, since the reduced length of any part represents the 

 quotient obtained by dividing the actual length by the product 

 of the conductibility and the section of the same part, it becomes 

 infinite Avhen the conductibility of this part vanishes, i. e. when 

 this part is a non-conductor of electricity. When, therefore, a 

 part of the circuit is a non-conductor, the electricity expands 

 uniformly over each of the other parts, and its change from one 

 part to the other is equal to the whole tension there situated. 

 This separation of the electricity, relative to the open circuit, 

 is far more simple than that in the closed circuit, which has 

 hitherto formed the object of our consideration, as is geome- 

 trically represented by the lines F G, HI, K L, (fig. 3) taking 

 a position parallel to A D. It distinctly demonstrates that the 

 difference between the electrical forces, occurring at any two 



* Gilbert's Annalen, vol. viii. pp. 205, 207, and 456. Vol. x. p, 11. 

 t Jahrgang, 1826. Partv. p.I17. 



