103 Prof. Clausius on the Conduction of 



where the position of the molecules is not yet sufficiently favour- 

 able to cause spontaneous decomposition, the cooperation of the 

 electric force may hasten the same. On the contrary, all de- 

 compositions which necessitate a motion of the partial molecules 

 opposed to the electric force will be retarded by the latter, and 

 thereby rendered less frequent. 



Let us consider a superficial element within this liquid per- 

 pendicular to the direction of the electric force acting at the 

 moment ; in the unit of time there are more positive partial mole- 

 cules passing through this element of surface in the j)ositive than in 

 the negative direction, and more negative partial molecules in the 

 negative than in the positive direction. But as for each kind of 

 partial molecules, two oppositely-directed passages nuitually de- 

 stroy each other's action, and as it is only the residual excess of 

 passages in one direction which demands consideration, the fore- 

 going may be more simply expressed thus : — a certain number of 

 positive partial molecules traverse the element of surface in the 

 positive direction, and a certain number of negative partial mole- 

 cules traverse it in the negative direction. The magnitudes of 

 these two numbers need not be equal, since they depend not 

 only upon the moving force, which is the same for both, but also 

 upon the degree of mobility, which, for many reasons, may be 

 different for different kinds of partial molecules. 



These opposite motions of the two kinds of partial molecules 

 constitute the galvanic current within the liquid. In order to 

 determine the intensity of this current, it is not necessary to 

 know how many positive partial molecules traverse the element 

 of surface in the positive, and how many negative ones in the 

 negative direction ; it will suffice if merely the sum of these 

 two numbers is known. For, no matter whether w-e start from 

 the hypothesis of two electricities, and assume that a negative 

 partial molecule possesses a certain quantity of free negative 

 electricity, or from the hypothesis of one electric fluid, and 

 conceive a negative partial molecule to possess less electricity 

 than is necessary for the neutral condition, in both cases we 

 must assume that a galvanic current is intensified just as much 

 by the motion of an electro-positive partial molecule in the direc- 

 tion of the current, as it is by that of an equally charged electro- 

 negative partial molecule in the opposite direction. Conse- 

 quently if, in the case of a molecular motion where an excess in 

 one direction exists for positive partial molecules alone, we re- 

 present by Q, .n the intensity of the current corresponding to 

 tbe passage of n ])ositive partial molecules in the positive direc- 

 tion through the element of surface in tlie unit of time, then, 

 in a similar manner, C (n-f-n') will represent the strength of 

 the current when simultaneously n positive partial inolccules 



