DYNAMICAL PRINCIPLES TO PHYSICAL PHENOMENA. 
525 
We can apply precisely the same method to any other physical effect which influences 
the resistance. Suppose that an alteration in the configuration Sp alters the resistance ; 
then, when the current u passes through the conductor, there will be a force, tending to 
increase p, equal to 
- ^( <rwa )f w ®.( 83 ) 
Let us now consider the effect which this term in the expression for T — V will 
produce on the chemical phenomena which we discussed in the earlier part of this 
paper. The alteration in T — Y due to this term is 
/3 
— icma — 
* n 
or 
— ^crafty?. 
Now, if the specific resistance depends, as we know it does to a very large extent in 
the case of liquids, on the substances dissolved in them, the chemical equilibrium will 
be affected by the passage of an electric current through them. 
Let us first take the case of solution ; then, when we were considering that subject, 
we showed that, if T — V were increased by — 8w, the change 80 in the temperature, 
which would produce the same effect as that produced by this change in T — Y, is 
given by the equation 
S6 _ dw 
e ~ ~dl’ 
where q' is the mass of the solution, and X the amount of heat absorbed when one 
gramme of the salt dissolves at constant temperature. Applying this formula to our 
case, we have 
SO 
0 
j3u z 
A~ 
(84) 
so that, if the specific resistance of the solution depends upon the amount of salt 
dissolved, then, if we make a current pass through a saturated solution, it will either 
absorb or deposit salt; if the specific resistance increases as the salt dissolves, it will 
deposit salt; if the resistance diminishes, it will absorb it. In trying the experiment, 
it would be well to use alternating currents to avoid any difficulty which might arise 
from the substances set free by electrolysis. 
Again, if we have dilute solutions of any number of substances, and if the resistance 
of the solution depends upon the relative proportion of these substances, then the 
