Page:The fundamental laws of electrolytic conduction.djvu/26

 evolves the two ions, chlorine and lead, the former being an anion, and the latter a cation. These terms, being once well defined, will, I hope, in their use enable me to avoid much periphrasis and ambiguity of expression. I do not mean to press them into service more frequently than will be required, for I am fully aware that names are one thing and science another.

It will be well understood that I am giving no opinion respecting the nature of the electric current now, beyond what I have done on former occasions; and that though I speak of the current as proceeding from the parts which are positive to those which are negative, it is merely in accordance with the conventional, though in some degree tacit, agreement entered into by scientific men, that they may have a constant, certain, and definite means of referring to the direction of the forces of that current.

[Section IV., including eight pages "On Some General Conditions of Electrochemical Decomposition," is here omitted.]

I have already said, when engaged in reducing common and voltaic electricity to one standard of measurement, and again when introducing my theory of electrochemical decomposition, that the chemical decomposing action of a current is constant for a constant quantity of electricity, notwithstanding the greatest variations in its sources, in its intensity, in the size of the electrodes used, in the nature of the conductors (or non-conductors) through which it is passed, or in other circumstances. The conclusive proofs of the truth of these statements shall be given almost immediately.

I endeavored upon this law to construct an instrument which should measure out the electricity passing through it, and which, being interposed in the course of the current used in any particular experiment, should serve at pleasure, either as a comparative standard of effect or as a positive measurer of this subtile agent.