90 Prof. E. Edlund on Galvanic Resistance as 



aether, we have by the theory i=8ah. Thus the current- 

 intensity is measured by the mass of aether which flows through 

 the cross section of the conductor in the unit of time : this I 

 have called the mechanical measure of the intensity *. If r 

 denotes the resistance of the unit of length of the conductor 

 when a current of unit intensity flows through it, then is r 

 the resistance in the usual signification of the term ; and this 

 resistance, in order to distinguish it from those which take 

 place with other current-intensities, I have named the principal 

 resistance to conduction f. Consequently, if r denotes the re- 

 sistance with the current-intensity i, we have, according to the 

 theory, r=r i, or, eliminating i, ?'=f 8aA. 



Theoretically, therefore, the resistance r is proportional to 

 the relative velocity between the aether molecules and the mo- 

 lecules of the conductor. If, then, the conductor receive a 

 velocity h Y in the same direction in which the aether flows, the 

 resistance r will be diminished ; for it will become 



r=r 8a(h — hi). 



If, on the contrary, we impart to the conductor the same velo- 

 city hi, but in the opposite direction, the resistance is aug- 

 mented and we get 



r=;r 8a(h + hi). 



After the current-intensity has become constant, the electro- 

 motive force of the series must, according to the theory, be 

 equal to the sum of all the resistances. If, then, the electro- 

 motive force and the principal resistance of the battery be de- 

 noted respectively by E and R ? an( i if r o signifies the principal 

 resistance in the conductor which connects the poles of the 

 battery, and i the intensity of the current, then is E = R^' + r i, 

 whence 



= E 



Bo + fo" 



If now to the conductor whose principal resistance is r a 

 velocity ±h is imparted, then, in accordance with what 

 was said above, if i x signifies the current-intensity, it makes 



E = IV'i + »*o(*i H 1 8ah), 

 whence 



. _ ^±r hahi 



h ~ U + r 

 Consequently the difference of the two currents becomes 



^i^f- tf 



* Theorie des Phenombnes Electriques, p. 10. f Ibid. p. 24. 



