256 WIEDEMANN ON THE MOTION OF LIQUIDS. 



By this law a simple measure is given for the electric tension 

 (or electromotive force) and its mechanical action, expressed in 

 atmospheric pressures, or in the unit of the force of gravity ; 

 this measure too is completely independent of all concurrent 

 circumstances. 



We have seen that the transportation of liquids by the gal- 

 vanic current is a manifestation solely of the electromotive force, 

 which may thus in a certain measure be viewed as a moving 

 force. 



Let us imagine an electromotive power, acting at the. surface 

 of contact of two liquids, forming a circuit ; and let us suppose 

 that in each liquid a porous partition is immersed whose sec- 

 tional area shall be equal to that of the liquid, and whose thick- 

 ness shall be unity. Then, by means of the generated galvanic 

 current, the liquids will move through the clay partitions with 

 forces which can be measured by hydrostatic pressures. Accord- 

 ing to the above law these pressures are directly proportional to 

 the resistances of the Uquids, and inversely proportional to the 

 surfaces of the clay partitions (the intensity of the current and 

 thickness of the clay partitions being in this case equal in both 

 liquids). The descents of the liquids measured by the differ- 

 ences of pressure on both sides of each clay partition of the 

 unit of thickness correspond therefore in like manner to the 

 same magnitudes. 



But according to Ohm^s mode of viewing the subject, the distri- 

 bution of electric tension has exactly the same connexion with 

 these same magnitudes. Here also the falls of electricity (the 

 difference of two ordinates, representing the electric tensions at 

 two points separated by the unit of length) are directly propor- 

 tional to the 7'esistances, and inversely as the transverse sectional 

 areas of the liquids. 



The foregoing experiments, therefore, furnish an experimental 

 proof that the mechanical actions of the galvanic current follow 

 exactly the same laws as Ohm has established for the distribu- 

 tion of electricity in the galvanic circuit. This proof may have 

 some value, as confirmatory of a former hypothesis ; and, on the 

 other hand, the intimate connexion of the newly-observed action 

 of the current, with earlier and already investigated actions, lend 

 an increased interest to the present investigation. 



