Page:The fundamental laws of electrolytic conduction.djvu/65

 For this purpose let us adopt the method of representation given by Berzelins in his works, in which the two ions are represented one below the other, and supposed to move by each other in a horizontal direction (Fig. 2). It is assumed that the electrolyte is brought into the liquid state by means of an indifferent non-conducting solvent.

If we can divide the liquid at any definite place, we shall find that the ions in each portion are in a different proportion after electrolysis has taken place than before. This proportion is determined by the distance through which each ion moves during the passage of the current.

If, for example, we make the assumption, tacitly made in former presentations, that these distances are equal, in which case both migrating ions meet half way between their original positions, a glance at Fig. 2 shows., that after electrolysis, that portion of liquid which borders on the anode will contain half an equivalent less cations than before. The converse is of course true for the other portion which is in contact with the cathode. By equivalent is understood the quantity of the component liberated.

If the two ions do not move through equal distances—that

Fig. 2

is, if they do not meet each other half way—then the side of the liquid in which the more rapidly moving ion makes its appearance will be increased by more than half an equivalent of it, and diminished by less than half an equivalent of the other ion. Fig. 3 shows this for the case when the anion moves, the cation of the distance. The anode side of the liquid contains of an equivalent more anions and of an equivalent less