1736.  This condition of things, which is very remarkable, accords perfectly with the effects observed in solid helices where wires are coiled over wires to the amount of five or six or more layers in succession, no diminution of effect on the outer ones being occasioned by those within.

S 22.  Note on electrical excitation.

1737.  That the different modes in which electrical excitement takes place will some day or other be reduced under one common law can hardly be doubted, though for the present we are bound to admit distinctions.  It will be a great point gained when these distinctions are, not removed, but understood.

1738.  The strict relation of the electrical and chemical powers renders the chemical mode of excitement the most instructive of all, and the case of two isolated combining particles is probably the simplest that we possess.  Here however the action is local, and we still want such a test of electricity as shall apply to it, to cases of current electricity, and also to those of static induction.  Whenever by virtue of the previously combined condition of some of the acting particles (923.) we are enabled, as in the voltaic pile, to expand or convert the local action into a current, then chemical action can be traced through its variations to the production of all the phenomena of tension and the static state, these being in every respect the same as if the electric forces producing them had been developed by friction.

1739.  It was Berzelius, I believe, who first spoke of the aptness of certain particles to assume opposite states when in presence of each other (959.).  Hypothetically we may suppose these states to increase in intensity by increased approximation, or by heat, &c. until at a certain point combination occurs, accompanied by such an arrangement of the forces of the two particles between themselves as is equivalent to a discharge, producing at the same time a particle which is throughout a conductor (1700.).

1740.  This aptness to assume an excited electrical state (which is probably polar in those forming non-conducting matter) appears to be a primary fact, and to partake of the nature of induction (1162.), for the particles do not seem capable of retaining their particular state independently of each other (1177.) or of matter in the opposite state.  What appears to be definite about the particles of matter is their assumption of a particular state, as the positive or negative, in relation to each other, and not of either one or other indifferently; and also the acquirement of force up to a certain amount.